JP7563008B2 - Resin product manufacturing system and resin product manufacturing method - Google Patents

Description

This disclosure relates to a resin product manufacturing system and a resin product manufacturing method.

Recently, plastic containers have become common as containers for holding food, beverages, and other contents. Plastic containers are manufactured by injection molding or biaxial stretch blow molding, in which a preform is inserted into a mold and then biaxially stretched and blown.

However, it is important to prevent defectively molded containers from being sold on the market, and to prevent foreign matter from being mixed into the resin that constitutes the container. Against this background, inspection devices for inspecting containers are known (see, for example, Patent Documents 1 and 2).

Patent Document 1 discloses an inspection device for inspecting the mouth of a container, which is capable of preventing a decrease in the illuminance of the inspection light. In addition, Patent Document 2 discloses an inspection device for containers whose mouth is formed in a narrowed bottle shape and is transparent to illumination light in a specified wavelength range.

Patent No. 6688501 Patent No. 6409178

However, with resin containers, it is necessary not only to prevent molding defects and the inclusion of foreign matter in the resin that makes up the container, but also to prevent discoloration of the container.

This disclosure has been made in consideration of these points, and aims to provide a resin product manufacturing system and a resin product manufacturing method that can suppress discoloration of resin products.

A resin product manufacturing system according to one embodiment includes a pellet input device that inputs first pellets made from a first resin and second pellets made from a second resin having a different color from the first resin, a mixer that mixes the first pellets and the second pellets input from the pellet input device, a molding device that molds a resin product using the first pellets and the second pellets mixed in the mixer, an inspection device that measures the color of the molded resin product, and a control device that controls at least one of the amount of the first pellets input from the pellet input device to the mixer and the amount of the second pellets input from the pellet input device to the mixer based on the color of the resin product measured by the inspection device.

A resin product manufacturing system according to one embodiment includes a pellet input device that inputs first pellets made from a first resin and second pellets made from a second resin having a different color from the first resin, a mixer that mixes the first pellets and the second pellets input from the pellet input device, a molding device that melts the first pellets and the second pellets mixed in the mixer to produce a molten resin material and molds a resin product using the resin material, an inspection device that measures the color of the produced resin material, and a control device that controls at least one of the amount of the first pellets input from the pellet input device to the mixer and the amount of the second pellets input from the pellet input device to the mixer based on the color of the resin material measured by the inspection device.

In one embodiment of the resin product manufacturing system, the inspection device may further measure the color of the molded resin product, and the control device may further control at least one of the amount of the first pellets fed from the pellet feeding device to the mixer and the amount of the second pellets fed from the pellet feeding device to the mixer based on the color of the resin product measured by the inspection device.

In one embodiment of the resin product manufacturing system, the first resin may be recycled polyester and the second resin may be virgin polyester.

In one embodiment of the resin product manufacturing system, the control device may change the amount of the second pellets fed from the pellet feeding device to the mixing device when the color measurement value measured by the inspection device is outside a predetermined range.

In one embodiment of the resin product manufacturing system, the control device may increase the amount of the second pellets fed from the pellet feeding device to the mixing device when the color measurement value measured by the inspection device is greater than a predetermined value.

In one embodiment of the resin product manufacturing system, the pellet feeding device may include a first pellet feeding device that feeds the first pellets into the mixer, and a second pellet feeding device that feeds the second pellets into the mixer.

A resin product manufacturing system according to one embodiment includes a resin supplying device that supplies a first resin and a second resin having a different color from the first resin, a decontamination device that heats the first resin and the second resin supplied from the resin supplying device to produce decontaminated molten resin, a pellet producing device that produces first pellets from the molten resin decontaminated by the decontamination device, a molding device that molds a resin product using the first pellets, an inspection device that measures the color of the molded resin product, and a control device that controls at least one of the amount of the first resin supplied from the resin supplying device to the decontamination device and the amount of the second resin supplied from the resin supplying device to the decontamination device based on the color of the resin product measured by the inspection device.

A resin product manufacturing system according to one embodiment includes a resin supplying device that supplies a first resin and a second resin having a different color from the first resin, a decontamination device that heats the first resin and the second resin supplied from the resin supplying device to produce a decontaminated molten resin, a pellet producing device that produces a first pellet from the molten resin decontaminated by the decontamination device, a molding device that melts the first pellet to produce a molten resin material and molds a resin product using the resin material, an inspection device that measures at least one of the colors of the molten resin, the first pellet, and the resin material, and a control device that controls at least one of the amount of the first resin supplied from the resin supplying device to the decontamination device and the amount of the second resin supplied from the resin supplying device to the decontamination device based on the color measured by the inspection device.

In one embodiment of the resin product manufacturing system, the inspection device may further measure the color of the molded resin product, and the control device may further control at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color of the resin product measured by the inspection device.

In one embodiment of the resin product manufacturing system, the first resin may be recycled polyester and the second resin may be virgin polyester.

In one embodiment of the resin product manufacturing system, the control device may change the amount of the second resin supplied from the resin supply device to the decontamination device when the color measurement value measured by the inspection device is outside a predetermined range.

In one embodiment of the resin product manufacturing system, the control device may increase the amount of the second resin supplied from the resin supply device to the decontamination device when the color measurement value measured by the inspection device is greater than a predetermined value.

In one embodiment of the resin product manufacturing system, the resin supply device may include a first resin supply device that supplies the first resin to the decontamination device, and a second resin supply device that supplies the second resin to the decontamination device.

In one embodiment, the resin product manufacturing system may further include a crystallization device provided between the pellet production device and the molding device, which crystallizes the first pellets, and a solid-state polymerization device provided between the crystallization device and the molding device, which solid-state polymerizes the crystallized first pellets.

In one embodiment, the resin product manufacturing system further includes a second pellet input device that is provided upstream of the molding device and inputs second pellets made from a third resin having a different color from the first resin, and a mixer that mixes the first pellets with the second pellets input from the second pellet input device, and the molding device may mold the resin product using the first pellets and the second pellets mixed in the mixer.

In one embodiment of the resin product manufacturing system, the control device may further control the amount of the second pellets fed from the second pellet feeding device to the mixing device based on the color measured by the inspection device.

In one embodiment of the resin product manufacturing system, the third resin may be virgin polyester.

In one embodiment of the resin product manufacturing system, the control device may change the amount of the second pellets fed from the second pellet feeding device to the mixing device when the color measurement value measured by the inspection device is outside a predetermined range.

In one embodiment of the resin product manufacturing system, the control device may increase the amount of the second pellets fed from the second pellet feeding device to the mixing device when the color measurement value measured by the inspection device is greater than a predetermined value.

In one embodiment of the resin product manufacturing system, a first pellet drying device may be provided upstream of the mixing device to dry the first pellets before they are mixed.

In one embodiment of the resin product manufacturing system, a second pellet drying device may be provided upstream of the mixing device to dry the second pellets before they are mixed.

In one embodiment, the resin product manufacturing system may further include a drying device provided between the mixing device and the molding device for drying the mixed first pellets and second pellets.

In one embodiment, the resin product manufacturing system may further include a mixing device that is provided upstream of the molding device and mixes the first pellets and the second pellets mixed by the mixing device.

In one embodiment, the resin product manufacturing system may further include a colorant injection device that injects colorant into the mixing device.

In one embodiment of the resin product manufacturing system, the color measurement value measured by the inspection device may be at least the B value of the RGB values.

In one embodiment of the resin product manufacturing system, the molding device is an injection molding device, and the resin product manufacturing system may further include a mold holding device that holds a mold having a cavity formed therein into which the resin injected from the injection molding device is filled.

A method for manufacturing a resin product according to one embodiment includes the steps of feeding a first pellet made from a first resin and a second pellet made from a second resin having a different color from the first resin from a pellet feeding device into a mixing device, mixing the first pellets and the second pellets in the mixing device, molding a resin product using the first pellets and the second pellets mixed in the mixing device with a molding device, measuring the color of the molded resin product with an inspection device, and controlling at least one of the amount of the first pellets fed from the pellet feeding device to the mixing device and the amount of the second pellets fed from the pellet feeding device to the mixing device based on the color of the resin product measured by the inspection device.

A method for manufacturing a resin product according to one embodiment includes the steps of: feeding a first pellet made from a first resin and a second pellet made from a second resin having a different color from the first resin from a pellet feeding device into a mixing device; mixing the first pellets and the second pellets in the mixing device; melting the first pellets and the second pellets mixed in the mixing device to produce a molten resin material and molding a resin product using the resin material in a molding device; measuring the color of the resin material with an inspection device; and controlling at least one of the amount of the first pellets fed from the pellet feeding device to the mixing device and the amount of the second pellets fed from the pellet feeding device to the mixing device based on the color of the resin material measured by the inspection device.

A method for manufacturing a resin product according to one embodiment includes the steps of: supplying a first resin and a second resin having a color different from that of the first resin from a resin supply device to a decontamination device; preparing a decontaminated molten resin by heating the first resin and the second resin supplied to the decontamination device in the decontamination device; preparing a first pellet from the molten resin decontaminated by the decontamination device; molding a resin product using the first pellet with a molding device; measuring the color of the molded resin product with an inspection device; and controlling at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color of the resin product measured by the inspection device.

A method for manufacturing a resin product according to one embodiment includes the steps of: supplying a first resin and a second resin having a different color from the first resin from a resin supply device to a decontamination device; preparing a decontaminated molten resin by heating the first resin and the second resin supplied to the decontamination device in the decontamination device; preparing a first pellet from the molten resin decontaminated by the decontamination device; preparing a molten resin material by melting the first pellet, and molding a resin product using the resin material in a molding device; measuring at least one of the colors of the molten resin, the first pellet, and the resin material with an inspection device; and controlling at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color measured by the inspection device.

This disclosure makes it possible to suppress discoloration of resin products.

FIG. 1 is a front view showing a resin product produced by a resin product manufacturing system according to a first embodiment. FIG. 2 is a schematic diagram showing the resin product manufacturing system according to the first embodiment. FIG. 3 is a cross-sectional view showing an injection molding device of the resin product manufacturing system according to the first embodiment. FIG. 4 is a flowchart showing a method for manufacturing a resin product according to the first embodiment. 5(a) to 5(c) are cross-sectional views showing the method for manufacturing a resin product according to the first embodiment. 6(a) to 6(c) are cross-sectional views showing the method for manufacturing a resin product according to the first embodiment. FIG. 7 is a schematic diagram showing a modified example of the resin product manufacturing system according to the first embodiment. FIG. 8 is a cross-sectional view showing an injection molding device of a modified example of the resin product manufacturing system according to the first embodiment. FIG. 9 is a schematic diagram showing another modified example of the resin product manufacturing system according to the first embodiment. FIG. 10 is a schematic diagram showing yet another modified example of the resin product manufacturing system according to the first embodiment. FIG. 11 is a schematic diagram showing still another modified example of the resin product manufacturing system according to the first embodiment. FIG. 12 is a schematic diagram showing a resin product manufacturing system according to the second embodiment. FIG. 13 is a flowchart showing a method for manufacturing a resin product according to the second embodiment. FIG. 14 is a schematic diagram showing a modified example of the resin product manufacturing system according to the second embodiment. FIG. 15 is a schematic diagram showing another modified example of the resin product manufacturing system according to the second embodiment. FIG. 16 is a schematic diagram showing a resin product manufacturing system according to the third embodiment. FIG. 17 is a flowchart showing a method for manufacturing a resin product according to the third embodiment.

First embodiment Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. FIGS. 1 to 6 are diagrams showing the first embodiment. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, it is possible to carry out appropriate modifications within the scope of the technical idea. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed descriptions may be omitted. In addition, the numerical values such as the dimensions of each member and the material names described in this specification are examples of embodiments, and are not limited thereto, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are intended to include substantially the same state in addition to their strict meanings.

First, a resin product manufactured by the resin product manufacturing system according to the present disclosure will be described. The resin product may be, for example, a preform used to manufacture plastic bottles. Although an example in which the resin product is a preform will be described, the resin product is not limited to such preforms, and the resin product may be a molded product such as a container manufactured by injection molding, injection compression molding, compression molding, or direct blow molding.

As shown in FIG. 1, the preform 100 has a mouth portion 101, a body portion 102, and a bottom portion 103.

A threaded portion 104 is provided on the outer periphery of the mouth portion 101 for screwing on a cap (not shown) after the preform 100 is biaxially stretch-blow molded to produce a plastic bottle (not shown). In addition, an annular support ring 105 protrudes from the lower portion of the mouth portion 101.

The body 102 has a cylindrical shape. The body 102 may have a tubular shape that gradually narrows in diameter from the mouth 101 side toward the bottom 103 side. The bottom 103 has a substantially hemispherical shape.

Such a preform 100 can be produced, for example, by injection molding a synthetic resin material.

Resin Product Manufacturing System Next, a resin product manufacturing system according to a first embodiment will be described with reference to Fig. 2 and Fig. 3. In this disclosure, "recycled polyester" means polyester that has been subjected to a recycling process. Also, "virgin polyester" means polyester that has not been subjected to a recycling process, i.e., unused polyester.

As shown in FIG. 2, the resin product manufacturing system 1 includes a pellet input device 11 that inputs recycled pellets (first pellets) Pe1 and virgin pellets (second pellets) Pe2, a mixer 13 that mixes the recycled pellets Pe1 and the virgin pellets Pe2, and an injection molding device (molding device) 30 that molds a resin product using the recycled pellets Pe1 and the virgin pellets Pe2 mixed in the mixer 13. The resin product manufacturing system 1 also includes an inspection device 70 that measures the color of the molded resin product, and a control device 75 connected to the inspection device 70. In this embodiment, the pellet input device 11 includes a recycled pellet input device (first pellet input device) 11A that inputs recycled pellets (first pellets) Pe1 into the mixer 13, and a virgin pellet input device (second pellet input device) 11B that inputs virgin pellets (second pellets) Pe2 into the mixer 13.

Here, the recycled pellets Pe1 are pellets made from recycled polyester (first resin), and the virgin pellets Pe2 are pellets made from virgin polyester (second resin) having a different color from the recycled polyester (first resin). In addition, the recycled pellets Pe1 and the virgin pellets Pe2 are each resin lumps with a maximum width of about 1 mm to 7 mm, and may have, for example, a cylindrical or spherical shape. In this embodiment, the virgin polyester is preferably colorless and transparent. On the other hand, the recycled polyester may have a certain yellowish color. In the following, "discoloration" is explained as meaning a change in color of a resin product based on a resin product made of virgin polyester (second resin).

In addition, in this disclosure, "polyester" refers to a copolymer of a dicarboxylic acid compound and a diol compound.

Examples of dicarboxylic acid compounds include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, pimelic acid, azelaic acid, methylmalonic acid, ethylmalonic acid, adamantanedicarboxylic acid, norbornenedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 5-sodiumsulfoisophthalic acid, phenylendanedicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, 9,9'-bis(4-carboxyphenyl)fluorene acid, and ester derivatives thereof.

Examples of diol compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalenedimethanol, decahydronaphthalenediethanol, norbornanedimethanol, norbornanediethanol, tricyclodecanedimethanol, tricyclodecaneethanol, tetracyclododecanedimethanol, tetracyclododecanediethanol, decalindimethanol, decalindiethanol, 5-cyclohexane ... -Methylol-5-ethyl-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane, cyclohexanediol, bicyclohexyl-4,4'-diol, 2,2-bis(4-hydroxycyclohexylpropane), 2,2-bis(4-(2-hydroxyethoxy)cyclohexyl)propane, cyclopentanediol, 3-methyl-1,2-cyclopentadiol, 4-cyclopentene-1,3-diol, adamantanediol, paraxylene glycol, bisphenol A, bisphenol S, styrene glycol, trimethylolpropane, and pentaerythritol.

Among polyesters, polyethylene terephthalate (hereinafter also referred to as PET), which is a copolymer of terephthalic acid and ethylene glycol, or modified polyethylene terephthalate in which a copolymerization monomer has been added to this, is preferred.

The polyester may contain monomers other than the dicarboxylic acid compound and the diol compound, but the content of such monomers is preferably 10 mol % or less, more preferably 5 mol % or less, and even more preferably 3 mol % or less, based on the total constituent units.

Next, we will explain the recycled pellet feeding device 11A, the virgin pellet feeding device 11B, and the mixer 13.

The recycled pellet input device 11A is for inputting the recycled pellets Pe1 into the mixer 13 and storing the recycled pellets Pe1. The recycled pellet input device 11A is configured to store the recycled pellets Pe1 that have been cooled to about room temperature. The recycled pellet input device 11A is connected to the control device 75 and is configured to be controlled by the control device 75. The volume of the recycled pellet input device 11A may be, for example, 20 m3 or ^more and 700 ^m3 or less.

The virgin pellet feeding device 11B is for feeding the virgin pellets Pe2 into the mixer 13 and storing the virgin pellets Pe2. The virgin pellet feeding device 11B stores the virgin pellets Pe2 cooled to about room temperature. The virgin pellet feeding device 11B is connected to the control device 75 and is configured to be controlled by the control device 75. The volume of the virgin pellet feeding device 11B may be, for example, 20 m3 or ^more and 700 ^m3 or less.

The mixer 13 mixes the recycled pellets Pe1 fed from the recycled pellet feeder 11A with the virgin pellets Pe2 fed from the virgin pellet feeder 11B. In the mixer 13, the recycled pellets Pe1 and the virgin pellets Pe2 are mixed so that they are substantially uniformly dispersed. This makes it possible to prevent variations in the quality of the resin products made from the recycled pellets Pe1 and the virgin pellets Pe2 (hereinafter also simply referred to as recycled pellets Pe1, etc.) mixed by the mixer 13.

The resin product manufacturing system 1 further includes a recycling pellet drying device (first pellet drying device) 12A that is provided upstream of the mixing device 13 and dries the recycling pellets Pe1 before mixing. In this embodiment, the recycling pellet drying device 12A is provided between the recycling pellet input device 11A and the mixing device 13. The recycling pellet drying device 12A is for drying the recycling pellets Pe1 stored in the recycling pellet input device 11A at about room temperature by heating them. As a result, the mixing device 13 is configured to be supplied with the recycling pellets Pe1 dried by the recycling pellet drying device 12A. In this recycling pellet drying device 12A, the recycling pellets Pe1 may be heated to, for example, 140°C or higher and 220°C or lower. By heating the recycling pellets Pe1 to 140°C or higher, the recycling pellets Pe1 can be efficiently dried. In addition, by setting the heating temperature of the recycling pellets Pe1 to 220°C or lower, the recycling pellets Pe1 can be prevented from being damaged by heat. In addition, by heating the recycled pellets Pe1 to a temperature of 220°C or less, further energy savings can be achieved, costs can be reduced in the manufacturing process for resin products, and yellowing of resin products can be reduced.

In this embodiment, "upstream" refers to the side closer to the recycled pellet input device 11A in the flow direction of the recycled pellets Pe1, or the side closer to the virgin pellet input device 11B in the flow direction of the virgin pellets Pe2. In this embodiment, "downstream" refers to the side closer to the die 40 described later in the flow direction of the recycled pellets Pe1 or virgin pellets Pe2.

The resin product manufacturing system 1 further includes a virgin pellet drying device (second pellet drying device) 12B that is provided upstream of the mixing device 13 and dries the virgin pellets Pe2 before mixing. In this embodiment, the virgin pellet drying device 12B is provided between the virgin pellet input device 11B and the mixing device 13. The virgin pellet drying device 12B is for drying the virgin pellets Pe2 stored in the virgin pellet input device 11B at about room temperature by heating them. As a result, the mixing device 13 is configured to be supplied with the virgin pellets Pe2 dried by the virgin pellet drying device 12B. In this virgin pellet drying device 12B, the virgin pellets Pe2 may be heated to, for example, 140°C or higher and 220°C or lower. By heating the virgin pellets Pe2 to 140°C or higher, the virgin pellets Pe2 can be efficiently dried. In addition, by setting the heating temperature of the virgin pellets Pe2 to 220°C or less, it is possible to prevent the virgin pellets Pe2 from being damaged by heat. In addition, by setting the heating temperature of the virgin pellets Pe2 to 220°C or less, it is possible to further save energy, reduce the cost of the manufacturing process for resin products, and reduce yellowing of resin products.

The resin product manufacturing system 1 may further include a mixing device M1 that is provided upstream of the injection molding device 30 and mixes the recycled pellets Pe1 and virgin pellets Pe2 mixed by the mixing device 13.

The stirring device M1 is disposed between the injection molding device 30 and the mixing device 13. The stirring device M1 stirs the recycled pellets Pe1 and the virgin pellets Pe2, thereby preventing the recycled pellets Pe1 and the like, which are maintained at a high temperature, from adhering to each other before being transported to the injection molding device 30. The stirring blades used in the stirring device M1 may be, for example, propeller blades, turbine blades, paddle blades, anchor blades, etc.

In the illustrated example, one stirring device M1 is provided. However, this is not limited to the above, and multiple stirring devices M1 may be provided. In particular, it is preferable to provide multiple stirring devices M1 along the flow direction of the recycled pellets Pe1, etc. This allows the recycled pellets Pe1, etc. to be stirred in multiple stages. This makes it possible to more effectively prevent the recycled pellets Pe1, etc., which are maintained at a high temperature, from adhering to each other before being transported to the injection molding device 30.

Next, the injection molding device 30 will be described. This injection molding device 30 melts the recycled pellets Pe1 and virgin pellets Pe2 mixed in the mixer 13 to produce molten resin (resin material) R, and uses the resin (resin material) R to injection mold a resin product. As shown in FIG. 3, the injection molding device 30 has a barrel 50 to which the recycled pellets Pe1, etc. are supplied, a conveying screw 60 provided in the barrel 50 to melt the recycled pellets Pe1, etc., and send the molten resin R downstream, a drive unit 65 to drive the conveying screw 60, a storage unit 80 provided downstream of the barrel 50 to store the resin R sent by the conveying screw 60, and a nozzle 90 to inject the resin R stored in the storage unit 80.

Of these, the barrel 50 is connected to the pipe Pi, which will be described later. A heater 51 for heating the barrel 50 is arranged on the outer periphery of the barrel 50. This allows the recycled pellets Pe1 and the like supplied into the barrel 50 to be heated. In addition, the barrel 50 is connected to a first flow path 31 for transporting the resin R sent by the transport screw 60 to the downstream side.

The conveying screw 60 plays a role of plasticizing the recycled pellets Pe1, etc., by rotating, to produce molten resin R. The conveying screw 60 is provided with a flight 61 that rotates in a spiral shape. The flight 61 applies a frictional force to the recycled pellets Pe1, etc., and the resin R, which plasticizes the recycled pellets Pe1, etc., and the resin R. The conveying screw 60 is configured to move forward and backward within the barrel 50 along the longitudinal direction of the barrel 50 by the above-mentioned drive unit 65. The conveying screw 60 moves forward relative to the barrel 50 when sending the resin R in the barrel 50 to the storage unit 80. The drive unit 65 that drives the conveying screw 60 may be, for example, a motor.

The storage section 80 includes a cylinder 81 that stores the resin R sent by the conveying screw 60, and a plunger 82 that pushes out the resin R stored in the cylinder 81. The plunger 82 is configured to advance while sliding within the cylinder 81 by a drive mechanism 83, and to retract while sliding within the cylinder 81 due to the pressure of the resin R. When the plunger 82 retracts relative to the cylinder 81, the resin R is stored and measured within the cylinder 81. On the other hand, when the plunger 82 advances relative to the cylinder 81, the resin R is injected from the nozzle 90 into the injection molding die (die 40).

The storage section 80 is connected to a second flow path 32 for transporting the resin R transported by the first flow path 31 to the storage section 80 and supplying the resin R stored in the storage section 80 to the nozzle 90. The above-mentioned first flow path 31 is connected to the middle of this second flow path 32. In addition, a three-way valve 33 is provided between the first flow path 31 and the second flow path 32 to prevent backflow of the resin R stored in the storage section 80 and to prevent the resin R from being supplied to the nozzle 90 when storing the resin R in the storage section 80. As described later, this three-way valve 33 is opened so that the first flow path 31 and the second flow path 32 communicate with each other when the resin R supplied to the barrel 50 is sent to the storage section 80. In this case, the first flow path 31 does not communicate with the nozzle 90. On the other hand, when the resin R stored in the storage section 80 is injected into the cavity 41 of the mold 40, the three-way valve 33 is opened so that the second flow path 32 and the nozzle 90 communicate with each other. In this case, the second flow path 32 does not communicate with the first flow path 31. In this way, when the resin R is sent to the storage section 80, the resin R is prevented from being supplied to the nozzle 90, and when the resin R is injected from the nozzle 90, the resin R is prevented from flowing back into the barrel 50.

The resin product manufacturing system 1 further includes a mold clamping device (mold holding device) 44 that holds a mold 40 in which a cavity 41 (see FIG. 3) is formed and filled with the resin R (see FIG. 3) injected from the injection molding device 30. The mold 40 held by the mold clamping device 44 includes a cavity side mold 42 and a core 43. Of these, the cavity side mold 42 is attached to a fixed platen 44a of the mold clamping device (mold holding device) 44. Note that components of the mold clamping device 44 other than the fixed platen 44a are omitted from the illustration. This mold 40 is designed to form a cavity 41 corresponding to the shape of the resin product to be manufactured by clamping the cavity side mold 42 and the core 43 using the mold clamping device 44. The above-mentioned mold clamping device 44 may be, for example, a direct pressure type or a toggle type.

Next, the inspection device 70 will be described. In this embodiment, the inspection device 70 includes a color camera. This color camera captures an image of a resin product to obtain information about the color of the resin product from the captured image. The size and/or shape of the area from which the color camera obtains information about the color of the resin product is not particularly limited as long as the area is within the resin product in the captured image. For example, the color camera may obtain information about the color of the resin product from any area of about 10 mm square in the body 102 of the preform 100. One pixel of a color image of such a color camera is represented by the gradation values of the three primary colors R (red), G (green), and B (blue), for example. In this case, the RGB elements of one pixel may be represented by, for example, 8-bit gradation values. That is, the color image may be composed of 24 bits (8 bits x 3 colors) for one pixel. Such an inspection device 70 is connected to a control device 75, and is configured so that the measured value of the color of the resin product (i.e., information about the color of the resin product) is transmitted to the control device 75 as a signal. The measured color value of the resin product may be, for example, the average value of the measured values of multiple resin products, for example, the average value of the measured values of 50 resin products.

Here, when white light is irradiated onto a resin product, if the resin product absorbs light with a wavelength corresponding to blue, light with a wavelength other than blue will be recognized as yellow. For this reason, in this embodiment, it is proposed that the inspection device 70 measures at least the B value of the RGB values of the resin product. This makes it possible to effectively inspect the resin product for yellowing.

Next, the control device 75 will be described. The control device 75 controls at least one of the amount of recycled pellets Pe1 fed from the pellet feeding device 11 to the mixer 13 and the amount of virgin pellets Pe2 fed from the pellet feeding device 11 to the mixer 13 based on the color of the resin product measured by the inspection device 70. Specifically, the control device 75 controls at least one of the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixer 13 and the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13 based on the color of the resin product measured by the inspection device 70.

In this embodiment, when the measured value of the color of the resin product measured by the inspection device 70 is outside a predetermined range, the control device 75 changes the amount of virgin pellets Pe2 fed from the pellet feed device 11 to the mixer 13. As an example, when the measured value of the color of the resin product measured by the inspection device 70 is greater than a predetermined value (i.e., greater than the upper limit of a predetermined range (hereinafter, also simply referred to as the upper limit)), the control device 75 may increase the amount of virgin pellets Pe2 fed from the virgin pellet feed device 11B to the mixer 13. This makes it possible to increase the content of virgin pellets Pe2 in the recycled pellets Pe1 and virgin pellets Pe2 (i.e., recycled pellets Pe1, etc.) mixed in the mixer 13. Therefore, it is possible to suppress discoloration (e.g., yellowing) of the resin product produced by the recycled pellets Pe1, etc. Here, the upper limit of the predetermined range is a reference value (threshold value) for determining whether or not the amount of virgin pellets Pe2 used in the resin product should be increased. Such an upper limit value can be set arbitrarily according to the color of the resin product to be obtained.

However, when the measured value of the color of the resin product becomes larger than the upper limit, recycled pellets Pe1, etc. are already present in the mixing device 13. In this way, even if the input amount of virgin pellets Pe2 to the mixing device 13 is increased, some of the recycled pellets Pe1, etc. (hereinafter, simply referred to as existing recycled pellets Pe1, etc.) already present in the mixing device 13 are used to produce the resin product without increasing the content of virgin pellets Pe2. Therefore, even if the input amount of virgin pellets Pe2 to the mixing device 13 is increased, a time lag occurs before the measured value of the color of the resin product becomes smaller. In addition, in this case, the measured value of the color of the resin product using existing recycled pellets Pe1, etc. may gradually increase. For this reason, it is preferable that the upper limit is a value that does not cause discoloration (e.g., yellowing) to the extent that it becomes defective in the resin product even if only existing recycled pellets Pe1, etc. are used without increasing the input amount of virgin pellets Pe2.

For example, the B value (i.e., the gradation value of B (blue)) may be used as such an upper limit value. In this case, the B value as the upper limit value may be 32 or more and 250 or less, and preferably 62 or more and 170 or less, when the RGB elements of one pixel are each represented by an 8-bit gradation value. As an example, the B value as the upper limit value may be 128 when the RGB elements of one pixel are each represented by an 8-bit gradation value.

On the other hand, when the color measurement value of the resin product measured by the inspection device 70 is equal to or lower than the upper limit, the control device 75 does not change the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixer 13 and the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13. This makes it possible to prevent the proportion of recycled pellets Pe1 used in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

Between each of the above-mentioned devices, a pipe Pi is provided to connect each device to each other. This pipe may be made of metal, for example, stainless steel. Furthermore, the inner surface of each pipe may be formed with fine irregularities. By forming fine irregularities on the inner surface of each pipe, friction between the recycled pellets Pe1 or virgin pellets Pe2 and the inner surface of each pipe is reduced, and the generation of fine powder can be suppressed.

Manufacturing Method of Resin Product Next, the operation of this embodiment having the above-mentioned configuration, that is, the manufacturing method of a resin product, will be described with reference to FIGS.

First, the recycled pellets Pe1 and virgin pellets Pe2 are fed from the pellet feeding device 11 into the mixer 13. In this case, the recycled pellets Pe1 are fed from the recycled pellet feeding device 11A into the mixer 13 (first pellet feeding process, reference symbol S1 in FIG. 4). At this time, the recycled pellets Pe1 stored in the recycled pellet feeding device 11A are first transported to the recycled pellet drying device 12A. Then, the recycled pellets Pe1 are heated in the recycled pellet drying device 12A. This dries the recycled pellets Pe1. Next, the recycled pellets Pe1 dried by the recycled pellet drying device 12A are supplied to the mixer 13.

In parallel with the first pellet input process (reference symbol S1 in FIG. 4), virgin pellets Pe2 are input from the virgin pellet input device 11B to the mixer 13 (second pellet input process, reference symbol S2 in FIG. 4). At this time, first, the virgin pellets Pe2 stored in the virgin pellet input device 11B are transported to the virgin pellet drying device 12B. Then, in the virgin pellet drying device 12B, the virgin pellets Pe2 are heated. This dries the virgin pellets Pe2. Next, the virgin pellets Pe2 dried by the virgin pellet drying device 12B are supplied to the mixer 13.

Next, the recycled pellets Pe1 and the virgin pellets Pe2 are mixed in the mixer 13 (mixing step, reference symbol S3 in FIG. 4). In the mixer 13, the recycled pellets Pe1 and the virgin pellets Pe2 are mixed so as to be dispersed approximately uniformly.

Next, the mixed recycled pellets Pe1 and virgin pellets Pe2 are stirred by the stirring device M1 (stirring process, reference symbol S4 in FIG. 4). This makes it possible to prevent the recycled pellets Pe1 and virgin pellets Pe2, which are maintained at a high temperature, from adhering to each other before being transported to the injection molding device 30. Thereafter, as shown in FIG. 5(a), the mixed recycled pellets Pe1 and virgin pellets Pe2 are transported to the injection molding device 30.

Next, a resin product is molded by the injection molding device 30 using the recycled pellets Pe1 and virgin pellets Pe2 mixed in the mixer 13 (injection process, reference symbol S5 in FIG. 4). At this time, first, as shown in FIG. 5(b), the mixed recycled pellets Pe1 and virgin pellets Pe2 are supplied to the barrel 50 (pellet supply process, reference symbol S51 in FIG. 4). In this case, the recycled pellets Pe1, etc. are supplied to the barrel 50 without being cooled, while being maintained at a temperature of 140°C or more and 220°C or less.

Next, the recycled pellets Pe1, etc. supplied into the barrel 50 are heated by the heater 51 around the conveying screw 60. At this time, the conveying screw 60 is rotated by the drive unit 65 (see FIG. 3). As a result, the recycled pellets Pe1, etc. supplied into the barrel 50 are subjected to a frictional force by the flight 61 of the conveying screw 60, and are plasticized by this frictional force. In this way, molten resin R is produced, as shown in FIG. 5(c).

The conveying screw 60 is gradually retracted relative to the barrel 50 by the pressure of the resin R. At this time, the three-way valve 33 is closed, and the resin R is not supplied to the storage section 80. In this way, a predetermined amount of resin R is stored in the barrel 50 and the first flow path 31. The conveying screw 60 may be retracted relative to the barrel 50 by the drive section 65.

Next, as shown in FIG. 6(a), the resin R in the barrel 50 is sent to the storage section 80 (sending step, reference symbol S52 in FIG. 4). At this time, first, the three-way valve 33 is opened so that the first flow path 31 and the second flow path 32 communicate with each other. In this case, the first flow path 31 does not communicate with the nozzle 90. Next, the rotation of the conveying screw 60 is stopped by the drive unit 65. Then, the conveying screw 60 is advanced relative to the barrel 50 by the drive unit 65. As a result, the resin R is sent into the cylinder 81 of the storage section 80 through the first flow path 31 and the second flow path 32. Note that when sending the resin R into the cylinder 81 of the storage section 80, the conveying screw 60 may be advanced relative to the barrel 50 while being rotated by the drive unit 65.

The plunger 82 of the storage section 80 advances relative to the cylinder 81 before the resin R is sent into the cylinder 81 (see Figures 5(b)-(c)), and gradually retreats relative to the cylinder 81 due to the pressure of the resin R sent into the cylinder 81. The resin R is then sent into the cylinder 81 of the storage section 80 until the plunger 82 inside the cylinder 81 retreats to a predetermined position. In this way, the resin R stored in the storage section 80 is metered.

Next, as shown in FIG. 6(b), the resin R stored in the storage section 80 is sent out toward the nozzle 90 (sending step, reference symbol S53 in FIG. 4). At this time, first, the three-way valve 33 is opened so that the second flow path 32 and the nozzle 90 communicate with each other. In this case, the second flow path 32 does not communicate with the first flow path 31. Next, the plunger 82 is advanced toward the cylinder 81 by the drive mechanism 83 (see FIG. 3) of the storage section 80. As a result, the resin R stored in the cylinder 81 is pushed out through the second flow path 32 and the nozzle 90 into the cavity 41 of the mold 40 (see FIG. 3).

The resin R extruded into the cavity 41 is then cooled and solidified within the cavity 41. In this way, a resin product is obtained within the cavity 41.

After that, as shown in FIG. 6(c), the above-mentioned feeding process (reference number S52 in FIG. 4) is carried out, and the resin R in the barrel 50 is fed to the storage section 80. Then, the above-mentioned sending out process (reference number S53 in FIG. 4, FIG. 6(b)) is carried out. In this manner, the above-mentioned feeding process (reference number S52 in FIG. 4) and sending out process (reference number S53 in FIG. 4) are repeated. This allows the continuous production of resin products.

Next, the color of the molded resin product is measured by an inspection device 70 (inspection process, reference symbol S6 in FIG. 4). In this inspection device 70, the B value of the RGB values of the resin product is measured. The measured color value of the resin product measured by the inspection device 70 is then sent as a signal to the control device 75. Note that the B value may be measured for each of, for example, 50 resin products. Also, the average of the measured B values may be used as the measured color value of the resin product.

Then, the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 is controlled based on the color of the resin product measured by the inspection device 70.

In this case, when a signal is sent to the control device 75, the control device 75 judges whether the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit (reference S7 in FIG. 4). If the control device 75 judges that the measured value is greater than the upper limit (YES in reference S7 in FIG. 4), the control device 75 increases the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 (control step, reference S8 in FIG. 4). This makes it possible to increase the content of virgin pellets Pe2 in the recycled pellets Pe1 and virgin pellets Pe2 (i.e., recycled pellets Pe1, etc.) mixed in the mixing device 13. This makes it possible to suppress discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc.

On the other hand, if the control device 75 determines that the measured value is equal to or lower than the upper limit (NO at S7 in FIG. 4), the control device 75 does not increase the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13. This makes it possible to prevent the proportion of recycled pellets Pe1 used in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

In this way, a resin product with reduced discoloration is obtained.

According to the present embodiment, the resin product manufacturing system 1 includes an inspection device 70 that measures the color of the molded resin product, and a control device 75 connected to the inspection device 70. The control device 75 controls the amount of virgin pellets Pe2 fed from the pellet feed device 11 to the mixer 13 based on the color of the resin product measured by the inspection device 70. This makes it possible to prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc. In particular, the inspection device 70 measures the color of the molded resin product. In this way, the inspection device 70 measures the color of the resin product that is actually produced, and thus the color of the resin product produced from the recycled pellets Pe1, etc. can be adjusted without considering the thermal history that the recycled pellets Pe1, etc. receive when producing the resin product. This makes it possible to effectively prevent discoloration of the resin product.

Furthermore, according to this embodiment, the control device 75 changes the amount of virgin pellets Pe2 fed from the pellet feeding device 11 to the mixing device 13 when the measured color value of the resin product measured by the inspection device 70 is outside a predetermined range. In this case, the control device 75 increases the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 when the measured color value of the resin product measured by the inspection device 70 is greater than the upper limit value. This makes it possible to more effectively prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc.

In addition, according to this embodiment, the resin product manufacturing system 1 further includes a recycled pellet drying device 12A that is provided upstream of the mixer 13 and dries the recycled pellets Pe1 before they are mixed. This allows the recycled pellets Pe1 supplied to the mixer 13 to be dried. This makes it possible to prevent the virgin pellets Pe2 from absorbing moisture from the recycled pellets Pe1 when the recycled pellets Pe1 and virgin pellets Pe2 are mixed.

In addition, according to this embodiment, the resin product manufacturing system 1 further includes a virgin pellet drying device 12B that is provided upstream of the mixing device 13 and dries the virgin pellets Pe2 before they are mixed. This allows the virgin pellets Pe2 supplied to the mixing device 13 to be dried. This makes it possible to prevent the recycled pellets Pe1 from absorbing moisture from the virgin pellets Pe2 when the recycled pellets Pe1 and the virgin pellets Pe2 are mixed.

In this manner, in this embodiment, when the recycled pellets Pe1 and the virgin pellets Pe2 are mixed, it is possible to prevent the recycled pellets Pe1 and the virgin pellets Pe2 from absorbing moisture. This allows the recycled pellets Pe1, etc. to be injection molded by the injection molding device 30 without the need for a process of drying the mixed recycled pellets Pe1 and virgin pellets Pe2. In other words, the process of reheating the recycled pellets Pe1, etc. can be omitted.

In addition, since the process of reheating the recycled pellets Pe1, etc. during injection molding can be omitted, energy savings and cost reduction in the manufacturing process of the resin product can be achieved.In addition, since the process of reheating the recycled pellets Pe1, etc. during injection molding can be omitted, the thermal history that the recycled pellets Pe1, etc. are subjected to can be reduced compared to when the recycled pellets Pe1, etc. are reheated during injection molding.This makes it possible to suppress discoloration (e.g., yellowing) of the resin product made from the recycled pellets Pe1, etc.

In addition, according to this embodiment, the resin product manufacturing system 1 further includes a mixing device M1 that is provided upstream of the injection molding device 30 and mixes the recycled pellets Pe1 and virgin pellets Pe2 mixed by the mixer 13. This makes it possible to prevent the recycled pellets Pe1 and virgin pellets Pe2 from adhering to each other before being transported to the injection molding device 30.

In addition, according to this embodiment, the color measurement value measured by the inspection device 70 is at least the B value of the RGB values of the resin product. This makes it possible to effectively inspect the resin product for yellowing. This makes it possible to more effectively prevent yellowing from occurring in resin products made from recycled pellets Pe1, etc.

In the above-described embodiment, the control device 75 controls the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 based on the color of the resin product measured by the inspection device 70, but the present invention is not limited to this. Although not shown, the control device 75 may control the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixing device 13 based on the color of the resin product measured by the inspection device 70. In this case, for example, when the control device 75 determines that the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit value, the control device 75 may reduce the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixing device 13. Also, although not shown, the control device 75 may control the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixing device 13 and the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 based on the color of the resin product measured by the inspection device 70.

In the above-described embodiment, the inspection device 70 measures the color of the molded resin product, but the present invention is not limited to this. For example, as shown in FIG. 7 and FIG. 8, the inspection device 70 may measure the color of the resin (resin material) R produced by the injection molding device 30. In this case, as shown in FIG. 8, a transparent member 31a may be connected to the first flow path 31 connected to the barrel 50. This transparent member 31a is configured so that the resin R passing through the first flow path 31 can be viewed from the outside, and the color camera of the inspection device 70 may capture the resin R passing through the first flow path 31 from the outside through this transparent member 31a. Such a transparent member 31a may be formed of a material such as glass. In the above-described example, the inspection device 70 measures the color of the resin R passing through the first flow path 31, but the inspection device 70 may measure the color of the resin R passing through the second flow path 32, or may measure the color of the resin R passing through the nozzle 90.

In addition, in this modified example, the control device 75 controls at least one of the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixer 13 and the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13 based on the color of the resin R measured by the inspection device 70.

In this case, for example, as shown in FIG. 7, the inspection device 70 may measure the color of the resin (resin material) R and also measure the color of the molded resin product. Then, the control device 75 may further control at least one of the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixer 13 and the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13 based on the color of the resin product measured by the inspection device 70. Note that the inspection device 70 may only measure the color of the resin (resin material) R without measuring the color of the molded resin product.

In this modified example, the inspection device 70 inspects the color of the resin (resin material) R when the resin R in the barrel 50 is fed into the storage section 80 (i.e., during the feeding process (see reference symbol S52 in FIG. 4). At this time, similar to the above-mentioned inspection process (reference symbol S6 in FIG. 4), the B value of the RGB values of the resin product is measured. The measured color value of the resin product measured by the inspection device 70 is then transmitted as a signal to the control device 75.

Next, based on the color of the resin R measured by the inspection device 70, at least one of the amount of recycled pellets Pe1 fed from the pellet feeding device 11 to the mixer 13 and the amount of virgin pellets Pe2 fed from the pellet feeding device 11 to the mixer 13 is controlled. At this time, for example, similar to the above-mentioned control process (reference symbol S8 in FIG. 4), the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13 is controlled based on the color of the resin R measured by the inspection device 70. Note that in this modified example, the inspection process to the control process may be performed in order after the injection process (reference symbol S5 in FIG. 4) similar to reference symbols S6 to S8 in FIG. 4.

As described above, according to this modified example, the resin product manufacturing system 1 includes an inspection device 70 that measures the color of the resin (resin material) R, and a control device 75 connected to the inspection device 70. The control device 75 controls at least one of the amount of recycled pellets Pe1 fed from the pellet feeding device 11 to the mixer 13 and the amount of virgin pellets Pe2 fed from the pellet feeding device 11 to the mixer 13, based on the color of the resin R measured by the inspection device 70. Even in this case, discoloration (e.g., yellowing) can be suppressed in the resin product produced from the recycled pellets Pe1, etc.

In addition, according to this modified example, the inspection device 70 further measures the color of the molded resin product. Then, the control device 75 further controls at least one of the amount of recycled pellets Pe1 fed from the pellet feed device 11 to the mixer 13 and the amount of virgin pellets Pe2 fed from the pellet feed device 11 to the mixer 13 based on the color of the resin product measured by the inspection device 70. Even in this case, discoloration (e.g., yellowing) of the resin product made from the recycled pellets Pe1, etc. can be suppressed. In particular, by the inspection device 70 measuring the color of the resin product to be actually produced, the color of the resin product made from the recycled pellets Pe1, etc. can be adjusted without considering the thermal history that the recycled pellets Pe1, etc. receive when producing the resin product. Therefore, discoloration of the resin product can be effectively suppressed.

In the above-described embodiment, an example has been described in which the first resin is recycled polyester and the second resin is virgin polyester, but this is not limited to this. Any resin can be used as the first resin and the second resin, as long as the second resin has a different color from the first resin.

In the above-described embodiment, an example of suppressing color change of a resin product based on a resin product made of a second resin has been described, but this is not limited to the above. Although not shown in the figures, the resin product may be configured to suppress color change based on a resin product made of a first resin.

In addition, in the above-described embodiment, an example has been described in which the control device 75 increases the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 when the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit value, but this is not limited to this. When the measured value of the color of the resin product measured by the inspection device 70 is smaller than a predetermined value (i.e., smaller than the lower limit value of a predetermined range (hereinafter also simply referred to as the lower limit value)), the control device 75 may control at least one of the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixing device 13 and the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13. For example, when the measured value of the color of the resin product measured by the inspection device 70 is smaller than the lower limit value, the control device 75 may reduce the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13. Alternatively, if the color measurement value of the resin product measured by the inspection device 70 is smaller than the lower limit, the control device 75 may increase the amount of recycled pellets Pe1 fed from the recycled pellet feeding device 11A to the mixer 13. In these cases, it is possible to prevent the content of recycled pellets Pe1 in the recycled pellets Pe1 and virgin pellets Pe2 (i.e., recycled pellets Pe1, etc.) mixed in the mixer 13 from becoming too low. This makes it possible to prevent the proportion of recycled pellets Pe1 used in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

As such a lower limit, for example, the B value (i.e., the gradation value of B (blue)) may be used, as in the upper limit. In this case, the B value as the lower limit may be 32 or more and 250 or less, and preferably 62 or more and 170 or less, when the RGB elements of one pixel are each represented by an 8-bit gradation value. As an example, the B value as the lower limit may be 62 when the RGB elements of one pixel are each represented by an 8-bit gradation value.

In the above-described embodiment, an example has been described in which the pellet input device 11 has a recycled pellet input device (first pellet input device) 11A that inputs recycled pellets (first pellets) Pe1 into the mixer 13, and a virgin pellet input device (second pellet input device) 11B that inputs virgin pellets (second pellets) Pe2 into the mixer 13, but this is not limited to the above. For example, as shown in FIG. 9, recycled pellets Pe1 and virgin pellets Pe2 may be stored in a single pellet input device 11. Then, the recycled pellets Pe1 and virgin pellets Pe2 may be input from this pellet input device 11 into the mixer 13 independently of each other.

In the above-described embodiment, an example was described in which the resin product manufacturing system 1 further includes a recycled pellet drying device 12A that is provided upstream of the mixing device 13 and dries the recycled pellets Pe1 before mixing. Also, an example was described in which the resin product manufacturing system 1 further includes a virgin pellet drying device 12B that is provided upstream of the mixing device 13 and dries the virgin pellets Pe2 before mixing. However, without being limited to this, as shown in FIG. 10, the resin product manufacturing system 1 may further include a drying device 12C that is provided between the mixing device 13 and the injection molding device 30 and dries the mixed recycled pellets Pe1 and virgin pellets Pe2. In this case, even if the temperatures of the recycled pellets Pe1 and virgin pellets Pe2 are low when the recycled pellets Pe1 and virgin pellets Pe2 are mixed, the recycled pellets Pe1 and virgin pellets Pe2 heated to the desired temperature can be transported to the injection molding device 30. This can improve the productivity of the resin product. The rest of the configuration of the drying device 12C is the same as that of the recycled pellet drying device 12A and the virgin pellet drying device 12B described above, so a detailed description will be omitted here.

In the above-described embodiment, an example has been described in which the resin product manufacturing system 1 includes a pellet input device 11 having a recycled pellet input device 11A and a virgin pellet input device 11B. In this case, as shown in FIG. 11, the resin product manufacturing system 1 may further include a colorant input device 11C that inputs a colorant C to the mixing device 13. The colorant input device 11C is for inputting the colorant C to the mixing device 13 and storing the colorant C. The volume of the colorant input device 11C may be, for example, 20 m ³ or more and 700 m ³ or less. The colorant C may be, for example, pellets in which a pigment is dispersed in a resin. A drying mechanism (not shown) for drying the colorant C may be provided between the colorant input device 11C and the mixing device 13. Alternatively, a drying mechanism (not shown) for drying the mixed recycled pellets Pe1, virgin pellets Pe2, and colorant C may be provided between the mixing device 13 and the injection molding device 30.

In this modified example, the control device 75 may further control the amount of colorant C added from the colorant adding device 11C to the mixing device 13 based on the color of the resin product measured by the inspection device 70.

In the above-described embodiment, the inspection device 70 measures the RGB values of the resin product, but this is not limited to the above. For example, the inspection device 70 may measure the Lab value of the resin product, the XYZ value of the resin product, or the HSV value of the resin product.

In the above-described embodiment, an example has been described in which the molding device that molds the resin product is the injection molding device 30, but this is not limited to this. Although not shown, for example, the molding device may be a molding device that performs injection compression molding, compression molding, or direct blow molding, and when molding a resin product using recycled pellets Pe1, etc., the resin product may be molded by injection compression molding, compression molding, or direct blow molding.

Second embodiment Next, a second embodiment will be described with reference to Figures 12 and 13. The second embodiment shown in Figures 12 and 13 is different from the first embodiment mainly in that the control device controls the supply amount of virgin polyester from the virgin polyester supply device to the decontamination device based on the color of the resin product measured by the inspection device. In Figures 12 and 13, the same parts as those in the first embodiment are given the same reference numerals and detailed description will be omitted.

Resin product manufacturing system First, a resin product manufacturing system according to a second embodiment will be described with reference to FIG. 12. As shown in FIG. 12, the resin product manufacturing system 1A includes a resin supplying device 2 that supplies recycled polyester (first resin) r1 and virgin polyester (second resin) r2, and a decontamination device 3 that heats the recycled polyester r1 and virgin polyester r2 supplied from the resin supplying device 2 to produce decontaminated molten resin r. The resin product manufacturing system 1A also includes a pellet manufacturing device 10 that produces recycled pellets Pe1 from the molten resin r decontaminated by the decontamination device 3, and an injection molding device 30 that molds a resin product using the recycled pellets Pe1. Furthermore, the resin product manufacturing system 1 includes an inspection device 70 that measures the color of the molded resin product, and a control device 75.

The resin supply device 2 includes a recycled polyester supply device (first resin supply device) 2A that supplies recycled polyester (first resin) r1 to the decontamination device 3, and a virgin polyester supply device (second resin supply device) 2B that supplies virgin polyester (second resin) r2 to the decontamination device 3. A drying mechanism (not shown) for drying the recycled polyester r1 may be provided between the recycled polyester supply device 2A and the decontamination device 3. A drying mechanism (not shown) for drying the virgin polyester r2 may be provided between the virgin polyester supply device 2B and the decontamination device 3.

The recycled polyester supplying device 2A is for supplying the recycled polyester r1 to the decontamination device 3. This recycled polyester supplying device 2A is connected to the control device 75 and is configured to be controlled by the control device 75. The recycled polyester supplying device 2A also contains resin flakes made from the recycled polyester r1. These resin flakes are made by sorting, crushing, and cleaning used plastic products. The used plastic products may be, for example, polyester containers. Such resin flakes are small pieces of resin bodies, and may be, for example, about 5 mm square to 15 mm square.

The virgin polyester supplying device 2B is for supplying virgin polyester r2 to the decontamination device 3. This virgin polyester supplying device 2B is connected to the control device 75 and is configured to be controlled by the control device 75. Furthermore, the virgin polyester supplying device 2B contains small pieces of resin bodies made from virgin polyester. Note that such small pieces of resin bodies may be, for example, 5 mm square or more and 15 mm square or less.

Next, the decontamination device 3 will be described. The decontamination device 3 mainly heats the recycled polyester r1 and the virgin polyester r2 under reduced pressure to volatilize and remove contaminants from the recycled polyester r1, and also melts the recycled polyester r1 and the virgin polyester r2. In this embodiment, the resin product manufacturing system 1A is equipped with one decontamination device 3.

The decontamination device 3 has a decontamination section 3a that decontaminates the recycled polyester r1 by heating the recycled polyester r1 and the virgin polyester r2, and a vacuum extruder 5 provided below the decontamination section 3a. An exhaust path 4 for reducing the pressure inside the decontamination section 3a is connected to the decontamination section 3a. The exhaust path 4 is connected to a vacuum pump (not shown). The pressure inside the decontamination section 3a is reduced by driving the vacuum pump. During decontamination, the pressure inside the decontamination section 3a is preferably 10 mbar or less. By setting the pressure inside the decontamination section 3a to 10 mbar or less, contaminants can be more effectively removed from the recycled polyester r1.

A heating mechanism (not shown) is provided in the decontamination section 3a. The heating mechanism heats the recycled polyester r1 supplied to the decontamination section 3a, causing the contaminants to volatilize. During decontamination, the temperature in the decontamination section 3a is preferably 180°C or higher. By setting the temperature in the decontamination section 3a to 180°C or higher, contaminants can be more effectively removed from the recycled polyester r1. During decontamination, nitrogen may be injected into the decontamination section 3a. By injecting nitrogen into the decontamination section 3a, oxidation of the recycled polyester r1 and the virgin polyester r2 in the decontamination section 3a is reduced, thereby reducing yellowing of the resin product. Although not shown, the decontamination device 3 may be provided with a drying chamber for drying the recycled polyester r1 while removing foreign matter such as dust from the recycled polyester r1 before heating the recycled polyester r1.

The vacuum extruder 5 connects the decontamination section 3a and the filter 6. A screw 5a is provided in the vacuum extruder 5, which rotates to melt the recycled polyester r1 and the virgin polyester r2 to produce the molten resin r. The screw 5a is rotated to extrude the molten resin r into the filter 6 provided downstream of the vacuum extruder 5. The recycled polyester r1 and the virgin polyester r2 may be melted in the decontamination section 3a to produce the molten resin r, and the molten resin (molten resin r) may be supplied to the vacuum extruder 5.

In this embodiment, "downstream" refers to the side closer to the mold 40 in the flow direction of the recycled polyester r1, virgin polyester r2, molten resin r, recycled pellets Pe1, or resin R.

The filter 6 is for removing minute foreign objects from the molten resin r. This filter 6 may be, for example, a mesh filter with many small holes having a pore size of about 25 μm or more and 40 μm or less.

A pellet making device 10 is provided downstream of the filter 6. The pellet making device 10 cuts the molten resin r extruded from the filter 6 into granules to produce recycled pellets Pe1.

The pellet making device 10 may make the recycled pellets Pe1 by a so-called hot cut method, in which the molten resin r is cut in a molten state without being cooled, or may make the recycled pellets Pe1 by a so-called cold cut method, in which the molten resin r is cut after being cooled. When cooling the molten resin r, a cooling method such as a water cooling method in which water is directly poured onto the molten resin r, a mist cooling method in which water is turned into a mist and poured onto the molten resin r, or an air cooling method in which air is blown onto the molten resin r can be used. Note that the pellet making device 10 can be configured in a known manner, and therefore detailed explanations are omitted in this specification.

In addition, the resin product manufacturing system 1A further includes a crystallization device 15 that is provided between the pellet production device 10 and the injection molding device 30 and crystallizes the recycled pellets Pe1, and a solid-state polymerization device 20 that is provided between the crystallization device 15 and the injection molding device 30 and solid-state polymerizes the crystallized recycled pellets Pe1.

The crystallization device 15 crystallizes the recycled pellets Pe1 supplied from the pellet production device 10 by heating them to about 140°C. In addition, nitrogen may be injected into the crystallization device 15 during crystallization. By injecting nitrogen into the crystallization device 15, oxidation of the recycled pellets Pe1 in the crystallization device 15 is reduced, thereby reducing yellowing of the resin product.

The solid-phase polymerization device 20 heats the recycled pellets Pe1 to solid-phase polymerize them, and serves to increase the viscosity (IV value) of the recycled pellets Pe1 by solid-phase polymerizing the recycled pellets Pe1. The solid-phase polymerization device 20 is provided with a pressure reducing mechanism and a heating mechanism (not shown), and is configured to heat the recycled pellets Pe1 to a desired temperature under a desired pressure. When the polyester of the above-mentioned recycled polyester r1 and virgin polyester r2 is, for example, polyethylene terephthalate, the IV value of the recycled pellets Pe1 may be increased to about 0.72 dL/g or more and 0.92 dL/g or less in the solid-phase polymerization device 20. The IV value can be measured by a measurement method that complies with the conditions of JIS K 7390:2003.

The solid-state polymerization apparatus 20 also plays a role in enhancing the decontamination effect of the recycled pellets Pe1 by heating the recycled pellets Pe1 under reduced pressure. That is, even if contaminants remain in the recycled pellets Pe1, the recycled pellets Pe1 are heated by the solid-state polymerization apparatus 20, so that the contaminants remaining in the recycled pellets Pe1 are volatilized and removed. During solid-state polymerization, the pressure inside the solid-state polymerization apparatus 20 is preferably 10 mbar or less. By setting the pressure inside the solid-state polymerization apparatus 20 to 10 mbar or less, contaminants can be more effectively removed from the recycled pellets Pe1.

During solid-state polymerization, the temperature inside the solid-state polymerization apparatus 20 is preferably 180°C or higher. By setting the temperature inside the solid-state polymerization apparatus 20 to 180°C or higher, contaminants can be more effectively removed from the recycled pellets Pe1. Furthermore, nitrogen may be injected into the solid-state polymerization apparatus 20 during solid-state polymerization. By injecting nitrogen into the solid-state polymerization apparatus 20, oxidation of the recycled pellets Pe1 in the solid-state polymerization apparatus 20 is reduced, thereby reducing yellowing of the resin product.

The resin product manufacturing system 1 further includes a conveying device 25 that conveys the solid-phase polymerized recycled pellets Pe1 to the injection molding device 30 while maintaining the pellets at a high temperature. The conveying device 25 is configured to convey the solid-phase polymerized recycled pellets Pe1 while maintaining the temperature at 140°C or higher and 220°C or lower. By conveying the recycled pellets Pe1 while maintaining the temperature at 140°C or higher, it is possible to prevent the temperature of the recycled pellets Pe1 from decreasing. This makes it possible to prevent the recycled pellets Pe1 from absorbing moisture. Therefore, the recycled pellets Pe1 can be injection molded by the injection molding device 30 without providing a process for drying the recycled pellets Pe1. That is, the process of reheating the recycled pellets Pe1 can be omitted. As a result, the manufacturing time of the resin product can be shortened and the productivity of the resin product can be improved. In addition, since the process of reheating the recycled pellets Pe1 during injection molding can be omitted, it is possible to save energy, reduce the cost of the manufacturing process of the resin product, and reduce the yellowing of the resin product. In addition, by keeping the temperature of the transported recycled pellets Pe1 at 220°C or less, it is possible to prevent the recycled pellets Pe1 from being damaged by heat. Furthermore, by keeping the temperature of the transported recycled pellets Pe1 at 220°C or less, it is possible to further save energy, reduce the cost of the resin product manufacturing process, and reduce the yellowing of the resin product.

Such a conveying device 25 has a conveying section 26 through which the recycled pellets Pe1 pass, and a heater 27 provided on the outer periphery of the conveying section 26. Of these, the conveying section 26 may be a metal, for example, stainless steel pipe. With this configuration, the recycled pellets Pe1 passing through the conveying section 26 are heated by the heater 27, so that the temperature of the recycled pellets Pe1 is maintained at 140°C or higher and 220°C or lower. In addition, the inner surface of the conveying section 26 may be formed with fine irregularities. By forming fine irregularities on the inner surface of the conveying section 26, friction between the high-temperature recycled pellets Pe1 and the inner surface of the conveying section 26 is reduced, and the generation of fine powder can be suppressed.

In addition, a stirring mechanism M2 may be arranged in the conveying section 26 of the conveying device 25. This stirring mechanism M2 stirs the recycled pellets Pe1 passing through the conveying section 26. By stirring the recycled pellets Pe1 passing through the conveying section 26 with the stirring mechanism M2, it is possible to prevent the recycled pellets Pe1 maintained at a high temperature from adhering to each other before being conveyed to the injection molding device 30. The stirring blade used in this stirring mechanism M2 may be, for example, a propeller blade, a turbine blade, a paddle blade, an anchor blade, etc. In addition, in the illustrated example, one stirring mechanism M2 is provided in the conveying section 26. However, this is not limited to this, and multiple stirring mechanisms M2 may be provided in the conveying section 26. In particular, it is preferable that multiple stirring mechanisms M2 are provided along the flow direction of the recycled pellets Pe1. This allows the recycled pellets Pe1 passing through the conveying section 26 to be stirred in multiple stages. This makes it possible to more effectively prevent the recycled pellets Pe1, which are maintained at a high temperature, from adhering to each other before being transported to the injection molding device 30.

Next, the control device 75 will be described. In this embodiment, the control device 75 controls at least one of the amount of recycled polyester r1 supplied from the resin supply device 2 to the decontamination device 3 and the amount of virgin polyester r2 supplied from the resin supply device 2 to the decontamination device 3 based on the color of the resin product measured by the inspection device 70. Specifically, the control device 75 controls at least one of the amount of recycled polyester r1 supplied from the recycled polyester supply device 2A to the decontamination device 3 and the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 based on the color of the resin product measured by the inspection device 70.

In this embodiment, the control device 75 changes the supply amount of virgin polyester r2 from the resin supply device 2 to the decontamination device 3 when the measured color value of the resin product measured by the inspection device 70 is outside a predetermined range. As an example, the control device 75 may increase the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3 when the measured color value of the resin product measured by the inspection device 70 is greater than a predetermined value (i.e., greater than the upper limit value of the predetermined range). This makes it possible to increase the content of virgin polyester r2 in the recycled pellets Pe1. This makes it possible to suppress discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1.

On the other hand, when the color measurement value of the resin product measured by the inspection device 70 is equal to or lower than the upper limit, the control device 75 does not change the amount of recycled polyester r1 supplied from the recycled polyester supply device 2A to the decontamination device 3 and the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3. This makes it possible to prevent the content of recycled polyester r1 in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

Manufacturing Method of Resin Product Next, the operation of this embodiment having the above-mentioned configuration, that is, the manufacturing method of a resin product, will be described with reference to FIG.

First, recycled polyester r1 and virgin polyester r2 are supplied from the resin supply device 2 to the decontamination device 3. In this case, recycled polyester r1 is supplied from the recycled polyester supply device 2A to the decontamination device 3 (first resin supply step, reference symbol S11 in FIG. 13). The inside of the decontamination section 3a of the decontamination device 3 is depressurized via the exhaust path 4 by a pump (not shown).

In parallel with the first resin supply process (reference symbol S11 in FIG. 13), virgin polyester r2 is supplied from the virgin polyester supply device 2B to the decontamination device 3 (second resin supply process, reference symbol S12 in FIG. 13).

Next, the recycled polyester r1 and virgin polyester r2 supplied to the decontamination device 3 are heated in the decontamination device 3 to produce a decontaminated molten resin r (decontamination process, reference symbol S13 in FIG. 13). At this time, first, in the decontamination section 3a, the recycled polyester r1 and virgin polyester r2 supplied to the decontamination section 3a are heated under reduced pressure by a heating mechanism (not shown). In addition, by heating the recycled polyester r1, contaminants attached to the recycled polyester r1 are volatilized. As a result, the contaminants are removed from the recycled polyester r1. Next, the recycled polyester r1 and virgin polyester r2 from which the contaminants have been removed are supplied to a vacuum extruder 5. Then, by rotating the screw 5a provided in the vacuum extruder 5, the recycled polyester r1 and virgin polyester r2 are melted to produce a molten resin r.

Next, recycled pellets Pe1 are produced from the molten resin r decontaminated by the decontamination device 3 (recycled pellet production process, reference symbol S14 in FIG. 13). At this time, the screw 5a installed in the vacuum extruder 5 is rotated to supply the molten resin r to the filter 6. The molten resin r supplied to the filter 6 passes through the filter 6, whereby minute foreign matter is removed. The molten resin r extruded from the filter 6 is then cut into granules by the pellet production device 10 to produce recycled pellets Pe1. At this time, the pellet production device 10 may produce recycled pellets Pe1 by a so-called hot cut method in which the molten resin r is cut in a molten state without being cooled.

Next, the recycled pellet Pe1 is crystallized (crystallization step, reference symbol S15 in FIG. 13). At this time, the recycled pellet Pe1 is first sent to the crystallization device 15. Next, the recycled pellet Pe1 is heated to about 140°C by the crystallization device 15. This causes the recycled pellet Pe1 to crystallize.

Next, the crystallized recycled pellets Pe1 are solid-phase polymerized in the solid-phase polymerization device 20 (solid-phase polymerization step, reference symbol S16 in FIG. 13). When the recycled pellets Pe1 are solid-phase polymerized, the recycled pellets Pe1 are first sent to the solid-phase polymerization device 20. Next, the recycled pellets Pe1 sent to the solid-phase polymerization device 20 are heated under reduced pressure. This increases the viscosity (IV value) of the recycled pellets Pe1 to a viscosity that is preferable in the injection step described below. At this time, for example, when the polyester of the recycled polyester r1 and the virgin polyester r2 is polyethylene terephthalate, the IV value of the recycled pellets Pe1 may be increased to about 0.72 dL/g or more and 0.92 dL/g or less in the solid-phase polymerization device 20. In addition, by heating the recycled pellets Pe1, even if contaminants remain in the recycled pellets Pe1, the contaminants remaining in the recycled pellets Pe1 are volatilized and removed.

In the solid-phase polymerization device 20, the recycled pellets Pe1 may be heated to a temperature of 180°C or higher and 220°C or lower. By heating the recycled pellets Pe1 to a temperature of 180°C or higher, the viscosity (IV value) of the recycled pellets Pe1 can be increased to a desired viscosity. In addition, by heating the recycled pellets Pe1 to a temperature of 180°C or higher, even if contaminants remain in the recycled pellets Pe1, the contaminants remaining in the recycled pellets Pe1 can be effectively removed by volatilizing them. In addition, by setting the temperature of the heated recycled pellets Pe1 to 220°C or lower, the recycled pellets Pe1 can be prevented from being damaged by heat. Furthermore, by setting the temperature of the heated recycled pellets Pe1 to 220°C or lower, energy saving and cost reduction in the manufacturing process of the resin product can be achieved.

Next, the solid-phase polymerized recycled pellets Pe1 are transported to the injection molding device 30 while being maintained at a temperature of 140°C or more and 220°C or less (transportation process, reference symbol S17 in FIG. 13). At this time, the recycled pellets Pe1 pass through the transport section 26 of the transport device 25. The recycled pellets Pe1 passing through the transport section 26 are heated by a heater 27 provided on the outer periphery of the transport section 26 while passing through the transport section 26. In this way, the recycled pellets Pe1 passing through the transport section 26 are transported to the injection molding device 30 while being maintained at a temperature of 140°C or more and 220°C or less.

At this time, the recycled pellets Pe1 may be stirred by the stirring mechanism M2. This makes it possible to prevent the recycled pellets Pe1, which are maintained at a high temperature, from adhering to each other before being transported to the injection molding device 30.

Next, the recycled pellets Pe1 are used to mold a resin product by the injection molding device 30. In this case, for example, similar to reference symbol S5 in FIG. 4, the pellet supply process (reference symbol S181 in FIG. 13), the feed process (reference symbol S182 in FIG. 13), and the feed process (reference symbol S183 in FIG. 13) are carried out in sequence, and the recycled pellets Pe1 transported to the injection molding device 30 are injection molded (injection process, reference symbol S18 in FIG. 13). In this manner, a resin product is obtained.

Next, the color of the molded resin product is measured by the inspection device 70 (inspection process, reference symbol S19 in FIG. 13). The measured value of the color of the resin product measured by the inspection device 70 is then transmitted as a signal to the control device 75.

Then, the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 is controlled based on the color of the resin product measured by the inspection device 70.

In this case, when a signal is sent to the control device 75, the control device 75 determines whether the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit (reference S20 in FIG. 13). If the control device 75 determines that the measured value is greater than the upper limit (YES in reference S20 in FIG. 13), the control device 75 increases the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 (control step, reference S21 in FIG. 13). This makes it possible to increase the content of virgin polyester r2 in the recycled pellets Pe1. This makes it possible to prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1.

On the other hand, if the control device 75 determines that the measured value is equal to or lower than the upper limit (NO at S20 in FIG. 13), the control device 75 does not increase the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3. This makes it possible to prevent the content of recycled polyester r1 in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

In this way, a resin product with reduced discoloration is obtained.

As described above, according to this embodiment, the resin product manufacturing system 1A includes an inspection device 70 that measures the color of the molded resin product, and a control device 75 connected to the inspection device 70. The control device 75 controls the supply amount of virgin polyester r2 from the resin supply device 2 to the decontamination device 3 based on the color of the resin product measured by the inspection device 70. This makes it possible to prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1. In particular, the inspection device 70 measures the color of the molded resin product. In this way, the inspection device 70 measures the color of the resin product actually produced, so that the color of the resin product produced from the recycled pellets Pe1 can be adjusted without considering the thermal history that the recycled pellets Pe1 receive when producing the resin product. This makes it possible to effectively prevent discoloration of the resin product.

In addition, according to this embodiment, the control device 75 changes the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 when the measured color value of the resin product measured by the inspection device 70 is outside a predetermined range. In this case, the control device 75 increases the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 when the measured color value of the resin product measured by the inspection device 70 is greater than the upper limit value. This makes it possible to more effectively prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1.

In the above-described embodiment, the control device 75 controls the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3 based on the color of the resin product measured by the inspection device 70, but the present invention is not limited to this. Although not shown, the control device 75 may control the supply amount of recycled polyester r1 from the recycled polyester supply device 2A to the decontamination device 3 based on the color of the resin product measured by the inspection device 70. In this case, for example, when the control device 75 determines that the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit value, the control device 75 may reduce the supply amount of recycled polyester r1 from the recycled polyester supply device 2A to the decontamination device 3. Also, although not shown, the control device 75 may control the supply amount of recycled polyester r1 from the recycled polyester supply device 2A to the decontamination device 3 and the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3 based on the color of the resin product measured by the inspection device 70.

In the above-described embodiment, the inspection device 70 has been described as measuring the color of the molded resin product, but the present invention is not limited to this. For example, as shown in FIG. 14, the inspection device 70 may measure at least one of the colors of the molten resin r, the recycled pellets Pe1, and the resin (resin material) R. In this case, although not shown, a transparent member configured to allow the molten resin r passing through the inside to be visible from the outside may be connected to the vacuum extruder 5. Furthermore, although not shown, a transparent member configured to allow the recycled pellets Pe1 passing through the inside to be visible from the outside may be connected to the conveying section 26 of the conveying device 25. Furthermore, although not shown, a transparent member configured to allow the resin R passing through the inside to be visible from the outside may be connected to the first flow path 31 connected to the barrel 50. Then, the color camera of the inspection device 70 may capture the molten resin r, the recycled pellets Pe1, and/or the resin R from the outside through these transparent members. These transparent members may be made of the same material as the transparent member 31a described above. In addition, in the above example, an example was described in which the inspection device 70 measures the color of the recycled pellets Pe1 passing through the conveying section 26 of the conveying device 25, but the inspection device 70 may also measure the color of the recycled pellets Pe1 passing through the piping Pi between the pellet production device 10 and the crystallization device 15, or may measure the color of the recycled pellets Pe1 passing through the piping Pi between the crystallization device 15 and the solid-state polymerization device 20.

In addition, in this modified example, the control device 75 controls at least one of the amount of recycled polyester r1 supplied from the recycled polyester supply device 2A to the decontamination device 3 and the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 based on the color measured by the inspection device 70.

In this case, for example, as shown in FIG. 14, the inspection device 70 may measure at least one of the colors of the molten resin r, the recycled pellets Pe1, and the resin (resin material) R, and may further measure the color of the molded resin product. Then, the control device 75 may further control at least one of the amount of recycled polyester r1 supplied from the recycled polyester supply device 2A to the decontamination device 3 and the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3, based on the color of the resin product measured by the inspection device 70. Note that the inspection device 70 may measure at least one of the colors of the molten resin r, the recycled pellets Pe1, and the resin (resin material) R without measuring the color of the molded resin product.

In this modified example, when the inspection device 70 measures the color of the molten resin r, the inspection device 70 inspects the color of the molten resin r during the decontamination process (see reference symbol S13 in FIG. 13). When the inspection device 70 measures the color of the recycled pellets Pe1, the inspection device 70 inspects the color of the recycled pellets Pe1 during the conveying process (see reference symbol S17 in FIG. 13). When the inspection device 70 measures the color of the resin (resin material) R, the inspection device 70 inspects the color of the resin (resin material) R when the resin R in the barrel 50 is fed into the storage section 80 (i.e., during the feeding process (see reference symbol S182 in FIG. 13). In these cases, the B value of the RGB value of the resin product is measured in the same manner as in the above-mentioned inspection process (reference symbol S19 in FIG. 13). The measured value of the color of the resin product measured by the inspection device 70 is then transmitted as a signal to the control device 75.

Then, based on the color measured by the inspection device 70, at least one of the amount of recycled polyester r1 supplied from the resin supply device 2 to the decontamination device 3 and the amount of virgin polyester r2 supplied from the resin supply device 2 to the decontamination device 3 is controlled. At this time, for example, similar to the above-mentioned control process (reference number S21 in FIG. 13), the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 is controlled based on the color measured by the inspection device 70. Note that in this modified example, the inspection process to the control process may be performed in order after the injection process (reference number S18 in FIG. 13), similar to reference numbers S19 to S21 in FIG. 13.

As described above, according to this modified example, the resin product manufacturing system 1 includes an inspection device 70 that measures at least one of the colors of the molten resin r, the recycled pellets Pe1, and the resin (resin material) R, and a control device 75 connected to the inspection device 70. The control device 75 controls at least one of the amount of recycled polyester r1 supplied from the recycled polyester supply device 2A to the decontamination device 3 and the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 based on the color measured by the inspection device 70. Even in this case, discoloration (e.g., yellowing) can be suppressed in the resin product produced from the recycled pellets Pe1.

In addition, according to this modified example, the inspection device 70 further measures the color of the molded resin product. Then, the control device 75 further controls at least one of the amount of recycled polyester r1 supplied from the recycled polyester supply device 2A to the decontamination device 3 and the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 based on the color of the resin product measured by the inspection device 70. Even in this case, discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1 can be suppressed. In particular, by the inspection device 70 measuring the color of the resin product actually produced, the color of the resin product produced from the recycled pellets Pe1 can be adjusted without considering the thermal history that the recycled pellets Pe1 receive when producing the resin product. Therefore, discoloration of the resin product can be effectively suppressed.

In addition, in the above-described embodiment, an example has been described in which the control device 75 increases the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3 when the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit value, but this is not limited to this. When the measured value of the color of the resin product measured by the inspection device 70 is smaller than the lower limit value, the control device 75 may control at least one of the supply amount of recycled polyester r1 from the recycled polyester supply device 2A to the decontamination device 3 and the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3. For example, when the measured value of the color of the resin product measured by the inspection device 70 is smaller than the lower limit value, the control device 75 may reduce the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3. Alternatively, when the measured value of the color of the resin product measured by the inspection device 70 is smaller than the lower limit value, the control device 75 may increase the supply amount of recycled polyester r1 from the recycled polyester supply device 2A to the decontamination device 3. In these cases, it is possible to prevent the content of recycled polyester r1 in the recycled pellets Pe1 from becoming too low. Therefore, it is possible to prevent the content of recycled polyester r1 in the resin product from becoming too low, and the environmental impact of the resin product can be reduced.

In the above-described embodiment, an example has been described in which the resin supplying device 2 has a recycled polyester supplying device (first resin supplying device) 2A that supplies recycled polyester (first resin) r1 to the decontamination device 3, and a virgin polyester supplying device (second resin supplying device) 2B that supplies virgin polyester (second resin) r2 to the decontamination device 3, but this is not limited to this. For example, as shown in FIG. 15, recycled polyester r1 and virgin polyester r2 may be contained in a single resin supplying device 2. Then, recycled polyester r1 and virgin polyester r2 may be supplied to the decontamination device 3 from this resin supplying device 2 independently of each other.

In addition, in the above-described embodiment, an example has been shown in which the resin product manufacturing system 1 is equipped with one decontamination device 3, but this is not limited to this. Although not shown, for example, the resin product manufacturing system 1 may be equipped with multiple decontamination devices 3. By having the resin product manufacturing system 1 equipped with multiple decontamination devices 3, the decontamination effect of the molten resin r can be improved.

Third embodiment Next, a third embodiment will be described with reference to Figures 16 and 17. The third embodiment shown in Figures 16 and 17 is different from the second embodiment mainly in that the injection molding device molds a resin product using the first pellets and the second pellets mixed in the mixer. In Figures 16 and 17, the same parts as those in the first or second embodiment are given the same reference numerals and detailed description thereof will be omitted.

Resin product manufacturing system First, a resin product manufacturing system according to the third embodiment will be described with reference to FIG. 16. As shown in FIG. 16, the resin product manufacturing system 1B is provided upstream of the injection molding device 30, and further includes a virgin pellet input device 11B that inputs virgin pellets Pe2 made from virgin polyester (third resin) r3, and a mixer 13 that mixes recycled pellets Pe1 and virgin pellets Pe2 input from the virgin pellet input device 11B. The resin product manufacturing system 1 is also provided upstream of the mixer 13 and further includes a virgin pellet drying device 12B that dries the virgin pellets Pe2 before being mixed. In this embodiment, the injection molding device 30 is configured to mold a resin product using the recycled pellets Pe1 and virgin pellets Pe2 mixed in the mixer 13. In this embodiment, "upstream" refers to the side closer to the virgin pellet input device 11B with respect to the flow direction of the virgin pellets Pe2.

Although not shown, a drying device 12C for drying the mixed recycled pellets Pe1 and virgin pellets Pe2 may be provided between the mixing device 13 and the injection molding device 30. In this case, even if the temperatures of the recycled pellets Pe1 and virgin pellets Pe2 are low when the recycled pellets Pe1 and virgin pellets Pe2 are mixed, the recycled pellets Pe1 and virgin pellets Pe2 heated to the desired temperature can be transported to the injection molding device 30. This improves the productivity of resin products.

As shown in FIG. 16, in this embodiment, the conveying device 25 is connected to the mixing device 13 and is configured to convey the solid-phase polymerized recycled pellets Pe1 to the mixing device 13 while maintaining the pellets at a high temperature. This makes it possible to prevent the temperature of the virgin pellets Pe2 from dropping when the recycled pellets Pe1 and the virgin pellets Pe2 are mixed. This makes it possible to prevent the virgin pellets Pe2 from absorbing moisture. Therefore, the recycled pellets Pe1 and the like can be injection molded by the injection molding device 30 without providing a process for drying the recycled pellets Pe1 and the like. That is, the process of reheating the recycled pellets Pe1 and the like can be omitted. As a result, the manufacturing time of the resin product can be shortened and the productivity of the resin product can be improved. In addition, since the process of reheating the recycled pellets Pe1 and the like during injection molding can be omitted, energy saving, cost reduction in the manufacturing process of the resin product, and reduction in yellowing of the resin product can be achieved.

Next, the control device 75 will be described. In this embodiment, the control device 75 further controls the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13 based on the color of the resin product measured by the inspection device 70.

In this embodiment, when the measured value of the color of the resin product measured by the inspection device 70 is outside a predetermined range, the control device 75 changes the amount of virgin pellets Pe2 fed from the virgin pellet feed device 11B to the mixer 13. As an example, when the measured value of the color of the resin product measured by the inspection device 70 is greater than a predetermined value (i.e., greater than the upper limit of the predetermined range), the control device 75 increases the amount of virgin polyester r2 fed from the virgin polyester supply device 2B to the decontamination device 3 and increases the amount of virgin pellets Pe2 fed from the virgin pellet feed device 11B to the mixer 13. This makes it possible to increase the content of virgin polyester r2 in the recycled pellets Pe1 and to increase the content of virgin pellets Pe2 in the recycled pellets Pe1 and virgin pellets Pe2 (i.e., recycled pellets Pe1, etc.) mixed in the mixer 13. This makes it possible to suppress discoloration (e.g., yellowing) of the resin product produced by the recycled pellets Pe1, etc.

On the other hand, when the measured color value of the resin product measured by the inspection device 70 is equal to or lower than the upper limit, the control device 75 does not increase the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3. In addition, the control device 75 does not change the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixer 13. This makes it possible to prevent the content of recycled polyester r1 in the recycled pellets Pe1 from becoming too low, and also to prevent the proportion of the recycled pellets Pe1 used in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

Manufacturing Method of Resin Product Next, the operation of this embodiment having the above-mentioned configuration, that is, the manufacturing method of a resin product, will be described with reference to FIG.

First, similar to steps S11 to S16 in FIG. 13, the first resin supplying process (S31 in FIG. 17), the second resin supplying process (S32 in FIG. 17), the decontamination process (S33 in FIG. 17), the recycled pellet production process (S34 in FIG. 17), the crystallization process (S35 in FIG. 17), and the solid-state polymerization process (S36 in FIG. 17) are carried out in this order.

Next, the recycled pellets Pe1 are fed into the mixer 13 (first pellet feeding step, reference symbol S37 in FIG. 17). At this time, the solid-phase polymerized recycled pellets Pe1 are first supplied to the mixer 13 by the conveying device 25 while being maintained at a temperature of 140°C or higher and 220°C or lower.

In parallel with the first pellet introduction step (reference number S37 in FIG. 17), virgin pellets Pe2 are introduced from the virgin pellet introduction device 11B into the mixer 13, similar to reference number S2 in FIG. 4 (second pellet introduction step, reference number S38 in FIG. 17).

After that, similar to symbols S3 to S4 in FIG. 4, a mixing process (symbol S39 in FIG. 17) and a stirring process (symbol S40 in FIG. 17) are performed in order. Then, a resin product is molded using the mixed recycled pellets Pe1 and virgin pellets Pe2. In this case, for example, similar to symbol S5 in FIG. 4, a pellet supply process (symbol S411 in FIG. 17), a feed process (symbol S412 in FIG. 17) and a feed process (symbol S413 in FIG. 17) are performed in order, and the recycled pellets Pe1 and virgin pellets Pe2 transported to the injection molding device 30 are injection molded (injection process, symbol S41 in FIG. 17). In this way, a resin product is obtained.

Next, the color of the molded resin product is measured by the inspection device 70 (inspection process, reference symbol S42 in FIG. 17). The measured value of the color of the resin product measured by the inspection device 70 is then transmitted as a signal to the control device 75.

Next, the amount of virgin polyester r2 supplied from the virgin polyester supply device 2B to the decontamination device 3 is controlled based on the color of the resin product measured by the inspection device 70. Also, the amount of virgin pellets Pe2 fed from the virgin pellet feed device 11B to the mixer 13 is controlled based on the color of the resin product measured by the inspection device 70.

In this case, when a signal is sent to the control device 75, the control device 75 judges whether the measured value of the color of the resin product measured by the inspection device 70 is greater than the upper limit (reference S43 in FIG. 17). If the control device 75 judges that the measured value is greater than the upper limit (YES in reference S43 in FIG. 17), the control device 75 increases the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3 and increases the input amount of virgin pellets Pe2 from the virgin pellet input device 11B to the mixer 13 (control step, reference S44 in FIG. 17). This makes it possible to increase the content of virgin polyester r2 in the recycled pellets Pe1 and the virgin pellets Pe2 (i.e., recycled pellets Pe1, etc.) mixed in the mixer 13, and to increase the content of virgin pellets Pe2. This makes it possible to suppress discoloration (e.g., yellowing) of the resin product produced by the recycled pellets Pe1, etc.

In particular, in this embodiment, when the control device 75 determines that the measured value is greater than the upper limit value, the control device 75 increases the amount of virgin pellets Pe2 fed into the mixing device 13. This makes it possible to shorten the time it takes for the content of virgin polyesters (second resin and third resin) r2 and r3 in the resin product to increase, compared to when the control device 75 only increases the supply amount of virgin polyester r2 to the decontamination device 3. That is, by increasing the amount of virgin pellets Pe2 fed into the mixing device 13, the content of virgin polyesters r2 and r3 in the resin product can be easily increased without waiting for the decontamination processing time in the decontamination process. Therefore, the time lag until the measured value of the color of the resin product becomes smaller can be reduced. As a result, discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc. can be effectively suppressed.

On the other hand, if the control device 75 determines that the measured value is equal to or lower than the upper limit (NO at S43 in FIG. 17), the control device 75 does not increase the supply amount of virgin polyester r2 from the virgin polyester supply device 2B to the decontamination device 3. The control device 75 also does not increase the input amount of virgin pellets Pe2 from the virgin pellet input device 11B to the mixer 13. This makes it possible to prevent the content of recycled polyester r1 in the recycled pellets Pe1 from becoming too low, and also to prevent the proportion of the recycled pellets Pe1 used in the resin product from becoming too low, thereby reducing the environmental impact of the resin product.

In this way, a resin product with reduced discoloration is obtained.

As described above, according to this embodiment, the resin product manufacturing system 1B is provided upstream of the injection molding device 30 and further includes a virgin pellet input device 11B that inputs virgin pellets Pe2 made from virgin polyester r3, and a mixer 13 that mixes recycled pellets Pe1 with the virgin pellets Pe2 input from the virgin pellet input device 11B. The injection molding device 30 is also configured to mold a resin product using the recycled pellets Pe1 and virgin pellets Pe2 mixed in the mixer 13. This can further reduce the environmental impact of the resin product.

In addition, according to this embodiment, the control device 75 further controls the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13 based on the color of the resin product measured by the inspection device 70. This makes it possible to effectively prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc. In particular, in this embodiment, the control device 75 increases the amount of virgin pellets Pe2 fed to the mixing device 13, so that the time lag until the measured value of the color of the resin product becomes smaller can be reduced. This makes it possible to effectively prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc.

In addition, according to this embodiment, when the measured color value of the resin product measured by the inspection device 70 is greater than the upper limit value, the control device 75 increases the amount of virgin pellets Pe2 fed from the virgin pellet feeding device 11B to the mixing device 13. This makes it possible to more effectively prevent discoloration (e.g., yellowing) of the resin product produced from the recycled pellets Pe1, etc.

In the above embodiment, the third resin is virgin polyester, but this is not limiting. Any resin can be used as the third resin as long as it has a different color from the first resin.

The components disclosed in each of the above embodiments and modifications may be combined as needed. Alternatively, some components may be deleted from all the components shown in each of the above embodiments and modifications.

REFERENCE SIGNS LIST 1 Resin product manufacturing system 1A Resin product manufacturing system 1B Resin product manufacturing system 2 Resin supply device 2A Recycled polyester supply device 2B Virgin polyester supply device 3 Decontamination device 10 Pellet production device 11 Pellet input device 11A Recycled pellet input device 11B Virgin pellet input device 11C Colorant input device 12A Recycled pellet drying device 12B Virgin pellet drying device 12C Drying device 13 Mixing device 15 Crystallization device 20 Solid-state polymerization device 30 Injection molding device 40 Mold 41 Cavity 44 Mold clamping device 70 Inspection device 75 Control device M1 Stirring device Pe1 Recycled pellet Pe2 Virgin pellet R Resin r Molten resin r1 Recycled polyester r2 Virgin polyester r3 Virgin polyester

Claims (28)

a pellet input device that inputs first pellets made from a first resin and second pellets made from a second resin having a color different from that of the first resin;
a mixer that mixes the first pellets and the second pellets that are input from the pellet input device;
a first pellet drying device provided upstream of the mixing device and configured to dry the first pellets before they are mixed;
a second pellet drying device provided upstream of the mixing device and configured to dry the second pellets before they are mixed;
a molding device that molds a resin product using the first pellets and the second pellets mixed in the mixing device;
An inspection device for measuring the color of the molded resin product;
a control device that controls at least one of an amount of the first pellets fed from the pellet feeding device to the mixing device and an amount of the second pellets fed from the pellet feeding device to the mixing device based on the color of the resin product measured by the inspection device ,
In the first pellet drying device, the first pellets are heated to 140° C. or more and 220° C. or less,
A resin product manufacturing system , wherein in the second pellet drying device, the second pellets are heated to 140°C or higher and 220°C or lower . a pellet input device that inputs first pellets made from a first resin and second pellets made from a second resin having a color different from that of the first resin;
a mixer that mixes the first pellets and the second pellets that are input from the pellet input device;
a first pellet drying device provided upstream of the mixing device and configured to dry the first pellets before they are mixed;
a second pellet drying device provided upstream of the mixing device and configured to dry the second pellets before they are mixed;
a molding device that melts the first pellets and the second pellets mixed in the mixing device to prepare a molten resin material and molds a resin product using the resin material;
An inspection device for measuring the color of the produced resin material;
a control device that controls at least one of an amount of the first pellets fed from the pellet feeding device to the mixing device and an amount of the second pellets fed from the pellet feeding device to the mixing device based on the color of the resin material measured by the inspection device ,
In the first pellet drying device, the first pellets are heated to 140° C. or more and 220° C. or less,
A resin product manufacturing system , wherein in the second pellet drying device, the second pellets are heated to 140°C or higher and 220°C or lower . The resin product manufacturing system according to claim 2, wherein the inspection device further measures the color of the molded resin product, and the control device further controls at least one of the amount of the first pellets fed from the pellet feeding device to the mixer and the amount of the second pellets fed from the pellet feeding device to the mixer based on the color of the resin product measured by the inspection device. The resin product manufacturing system according to any one of claims 1 to 3, wherein the first resin is recycled polyester and the second resin is virgin polyester. The resin product manufacturing system according to any one of claims 1 to 4, wherein the control device changes the amount of the second pellets fed from the pellet feeding device to the mixing device when the color measurement value measured by the inspection device is outside a predetermined range. The resin product manufacturing system according to claim 4, wherein the control device increases the amount of the second pellets fed from the pellet feeding device to the mixing device when the color measurement value measured by the inspection device is greater than a predetermined value. The resin product manufacturing system according to any one of claims 1 to 6, wherein the pellet input device includes a first pellet input device that inputs the first pellets into the mixer, and a second pellet input device that inputs the second pellets into the mixer. a resin supplying device that supplies a first resin and a second resin having a color different from that of the first resin;
a decontamination device that prepares a decontaminated molten resin by heating the first resin and the second resin supplied from the resin supply device;
a pellet preparation device that prepares first pellets from the molten resin decontaminated by the decontamination device;
a molding device that molds a resin product using the first pellets;
a second pellet input device provided upstream of the molding device and configured to input second pellets made of a third resin having a color different from that of the first resin;
a mixer that mixes the first pellets with the second pellets introduced from the second pellet introduction device;
a second pellet drying device provided upstream of the mixing device and configured to dry the second pellets before they are mixed;
An inspection device for measuring the color of the molded resin product;
and a control device that controls at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color of the resin product measured by the inspection device ;
A resin product manufacturing system , wherein in the second pellet drying device, the second pellets are heated to 140°C or higher and 220°C or lower . a resin supplying device that supplies a first resin and a second resin having a color different from that of the first resin;
a decontamination device that prepares a decontaminated molten resin by heating the first resin and the second resin supplied from the resin supply device;
a pellet preparation device that prepares first pellets from the molten resin decontaminated by the decontamination device;
a molding device that melts the first pellets to prepare a molten resin material and molds a resin product using the resin material;
a second pellet input device provided upstream of the molding device and configured to input second pellets made of a third resin having a color different from that of the first resin;
a mixer that mixes the first pellets with the second pellets introduced from the second pellet introduction device;
a second pellet drying device provided upstream of the mixing device and configured to dry the second pellets before they are mixed;
an inspection device for measuring at least one of a color of the molten resin, a color of the first pellets, and a color of the resin material;
and a control device that controls at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color measured by the inspection device ;
A resin product manufacturing system , wherein in the second pellet drying device, the second pellets are heated to 140°C or higher and 220°C or lower . The resin product manufacturing system according to claim 9, wherein the inspection device further measures the color of the molded resin product, and the control device further controls at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color of the resin product measured by the inspection device. The resin product manufacturing system according to any one of claims 8 to 10, wherein the first resin is recycled polyester and the second resin is virgin polyester. The resin product manufacturing system according to any one of claims 8 to 11, wherein the control device changes the amount of the second resin supplied from the resin supply device to the decontamination device when the color measurement value measured by the inspection device is outside a predetermined range. The resin product manufacturing system according to claim 11, wherein the control device increases the amount of the second resin supplied from the resin supply device to the decontamination device when the color measurement value measured by the inspection device is greater than a predetermined value. The resin product manufacturing system according to any one of claims 8 to 13, wherein the resin supplying device includes a first resin supplying device that supplies the first resin to the decontamination device, and a second resin supplying device that supplies the second resin to the decontamination device. The resin product manufacturing system according to any one of claims 8 to 14, further comprising a crystallization device provided between the pellet preparation device and the molding device, for crystallizing the first pellets, and a solid-state polymerization device provided between the crystallization device and the molding device, for solid-state polymerizing the crystallized first pellets. The resin product manufacturing system according to claim 8 , wherein the molding device molds the resin product using the first pellets and the second pellets mixed in the mixer. The resin product manufacturing system according to claim 16, wherein the control device further controls the amount of the second pellets fed from the second pellet feeding device to the mixing device based on the color measured by the inspection device. The resin product manufacturing system according to claim 16 or 17, wherein the third resin is virgin polyester. The resin product manufacturing system according to any one of claims 16 to 18, wherein the control device changes the amount of the second pellets fed from the second pellet feeding device to the mixing device when the color measurement value measured by the inspection device is outside a predetermined range. The resin product manufacturing system according to claim 18, wherein the control device increases the amount of the second pellets fed from the second pellet feeding device to the mixing device when the color measurement value measured by the inspection device is greater than a predetermined value. The resin product manufacturing system according to claim 1 , further comprising a stirring device provided upstream of the molding device and configured to stir the first pellets and the second pellets mixed by the mixing device. The resin product manufacturing system according to any one of claims 1 to 21 , further comprising a colorant supply device that supplies a colorant to the mixing device. The resin product manufacturing system according to claim 1 , wherein the measurement value of the color measured by the inspection device is at least a B value among RGB values. The resin product manufacturing system according to any one of claims 1 to 23, wherein the molding device is an injection molding device, and the resin product manufacturing system further comprises a mold holding device that holds a mold having a cavity formed therein into which resin injected from the injection molding device is filled. A step of feeding first pellets made from a first resin and second pellets made from a second resin having a color different from that of the first resin from a pellet feeding device into a mixer;
mixing the first pellets and the second pellets in the mixer;
a step of molding a resin product by a molding device using the first pellets and the second pellets mixed by the mixing device;
measuring the color of the molded resin product with an inspection device;
and controlling at least one of an amount of the first pellets fed from the pellet feeding device to the mixing device and an amount of the second pellets fed from the pellet feeding device to the mixing device based on the color of the resin product measured by the inspection device ,
The step of feeding the first pellets from the pellet feeding device into the mixer includes a step of heating the first pellets in a first pellet drying device and a step of heating the second pellets in a second pellet drying device,
In the step of heating the first pellets, the first pellets are heated to 140° C. or more and 220° C. or less;
The method for producing a resin product, wherein in the step of heating the second pellets, the second pellets are heated to 140°C or higher and 220°C or lower . A step of feeding first pellets made from a first resin and second pellets made from a second resin having a color different from that of the first resin from a pellet feeding device into a mixer;
mixing the first pellets and the second pellets in the mixer;
melting the first pellets and the second pellets mixed in the mixer to prepare a molten resin material, and molding a resin product using the resin material in a molding device;
measuring the color of the resin material with an inspection device;
and controlling at least one of an amount of the first pellets fed from the pellet feeding device to the mixer and an amount of the second pellets fed from the pellet feeding device to the mixer based on the color of the resin material measured by the inspection device ,
The step of feeding the first pellets from the pellet feeding device into the mixer includes a step of heating the first pellets in a first pellet drying device and a step of heating the second pellets in a second pellet drying device,
In the step of heating the first pellets, the first pellets are heated to 140° C. or more and 220° C. or less;
The method for producing a resin product, wherein in the step of heating the second pellets, the second pellets are heated to 140°C or higher and 220°C or lower . A step of supplying a first resin and a second resin having a color different from that of the first resin from a resin supply device to a decontamination device;
preparing a decontaminated molten resin by heating the first resin and the second resin supplied to the decontamination apparatus in the decontamination apparatus;
preparing a first pellet from the molten resin decontaminated by the decontamination device;
A step of feeding the first pellets and second pellets made of a third resin having a color different from that of the first resin into a mixer;
molding a resin product using the first pellets and the second pellets with a molding device;
measuring the color of the molded resin product with an inspection device;
and controlling at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color of the resin product measured by the inspection device ;
The step of feeding the second pellets into the mixer includes heating the second pellets in a second pellet drying device;
The method for producing a resin product, wherein in the step of heating the second pellets, the second pellets are heated to 140°C or higher and 220°C or lower . A step of supplying a first resin and a second resin having a color different from that of the first resin from a resin supply device to a decontamination device;
preparing a decontaminated molten resin by heating the first resin and the second resin supplied to the decontamination apparatus in the decontamination apparatus;
preparing a first pellet from the molten resin decontaminated by the decontamination device;
A step of feeding the first pellets and second pellets made of a third resin having a color different from that of the first resin into a mixer;
melting the first pellets and the second pellets to prepare a molten resin material, and molding a resin product using the resin material with a molding device;
measuring at least one of a color of the molten resin, a color of the first pellets, and a color of the resin material with an inspection device;
and controlling at least one of the amount of the first resin supplied from the resin supply device to the decontamination device and the amount of the second resin supplied from the resin supply device to the decontamination device based on the color measured by the inspection device ;
The step of feeding the second pellets into the mixer includes heating the second pellets in a second pellet drying device;
The method for producing a resin product, wherein in the step of heating the second pellets, the second pellets are heated to 140°C or higher and 220°C or lower .