JP2840518B2 - Method and apparatus for adjusting bulk density of pulverized foamed resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for adjusting the bulk density of a pulverized foamed resin product.

[0002]

2. Description of the Related Art Conventionally, as a method for reusing a resin foam such as waste polystyrene foam, a resin foam is appropriately ground, mixed with a primary foamed new material, and the new material is secondarily foamed under heating and humidification. As a result, integral molding is performed as a foam molded article. Such remanufactured products are effectively used, for example, as relatively large foam resin blocks buried in the soil when embanking on soft ground or when constructing a platform, or as a core material of a float. Have been.

[0003] At the time of molding, the foamed resin material is first pulverized by a pulverizer and, if necessary, secondarily pulverized waste foamed resin material is directly charged into a molding machine together with a new material and heated steam is injected to form a foam. It is.

[0004]

Generally, in the production of a foamed molded product, the desired product is obtained by adjusting the temperature of the heated steam and the amount of the supplied steam and adjusting the foaming conditions to change the bulk density (expansion ratio). I try to gain weight. When foam molding is performed using only a new material, the desired bulk density can be easily obtained by this method, and the initial adjustment purpose can be achieved. However, the crushed waste resin foam material usually has a lower bulk density than the state before crushing, and the rate of change varies depending on crushing conditions. It is difficult to always control the final product to be formed at a required average bulk density (weight per unit volume) by adjusting the mixing ratio when molding by molding. In addition, the resin material after pulverization is not necessarily all pulverized to the same particle size, and usually becomes a mixture of aggregates having different bulk densities. Furthermore, it was virtually impossible to make everything the same weight.

Further, in order to obtain a molded article having a bulk density equal to or higher than the bulk density of the waste resin material to be mixed, the mixing ratio of the crushed waste resin material must be reduced. , Could not raise enough cost merit. When the resin product is pulverized by a pulverizer, in addition to the block-shaped pulverized product, avoid including bubbles that have been broken into thin films or long fibers that have gathered in a wavy shape. Can not do. Since this type of material has a specific gravity smaller than that of the block-shaped pulverized product, when the pulverized product is mixed with a new material and put into a foam molding machine, the product becomes a floating state. When molding was performed for a long period of time, the suspended matter caused clogging of the steam supply port of the molding machine.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the inconvenience caused by the above-mentioned pulverized product when a new foam molded product is produced by mixing a pulverized product of waste resin foam into a new material. More specifically, it is an object of the present invention to provide a method and an apparatus for making a ground resin product having a desired bulk specific gravity so that a final product having a desired weight can be easily formed.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the object, the present invention relates to a method of stirring a predetermined amount of a crushed foamed resin under a predetermined heating condition for a required time, during which the foamed resin is stirred. A method for adjusting the bulk density of a foamed resin pulverized product in which the whole pulverized product is adjusted by partially heat shrinking the pulverized product, wherein one of the foamed resin pulverized products subjected to stirring for a predetermined time under a predetermined heating condition. The method further comprises the step of taking out the part, measuring the bulk density thereof, and adjusting the heating conditions and / or the stirring time based on the measured value.

[0008] The present invention further provides an apparatus for carrying out the above-mentioned adjusting method, comprising:
A stirring tank for receiving and stirring the foamed resin pulverized product from the fixed amount supply means, a stirring means for stirring the foamed resin pulverized product in the stirring tank, and a heating for heating the foamed resin pulverized product in the stirring tank The present invention also discloses an apparatus for adjusting the bulk density of a crushed foamed resin product, comprising: a means for weighing the crushed foamed resin product subjected to stirring and heating.

The term "pulverized foamed resin" as used in the present invention refers to all pulverized foamed resins which can be usually reused, and is not limited thereto. However, the present invention is particularly effective in the case of pulverized styrene foam. To work.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings. FIG. 1 is a partial sectional view showing one embodiment of a processing apparatus suitable for carrying out the processing method of the present invention.

This processing apparatus is roughly divided into a pulverized product accommodating means 10, a pulverized product stirring / heating means 30, and a weighing / unloading means 50. The crushed product storage means 10 includes a hopper 11 for receiving and holding the crushed product of the foamed resin material.
And a fixed amount feeding means 20. The hopper 11 has an input port 12 and an output port 13 and has a level sensor 1 provided at a lower position and an upper position thereof by appropriate means such as optical means.
4 and 15. A pulverized resin foam material is fed into the inlet 12 from a conventionally known pulverizer (not shown) via a blower. Downstream of the discharge port 13 is a fixed-quantity feeding means 20 for measuring the discharged pulverized product and sending the pulverized product to a pulverized product stirring / heating means 30 described later. The fixed amount feeding means 20 fulfills a valve function and a metering function. As shown in FIG.
It has a gutter-shaped measuring mass 22 and a motor 25 for rotating the measuring mass 22. The motor 25 and the rotating shaft are connected via an appropriate speed control mechanism 26.

A guide plate 31 having an upwardly convex cross-sectional shape is located on the delivery side of the measuring mass 22, and the guide plate 31 extends into the pulverized product stirring / heating means 30. That is, the stirring / heating means 30 has a stirring tank 40 surrounded by both side walls 32 and 33 and a cylindrical casing 34 located between the side walls, as shown in FIG.
The guide plate 31 extends through the opening 35 into the stirring tank 40. Further, the cylindrical casing 34 has a discharge opening 36 below, and a shutter 37 is slidably disposed near the discharge opening 36. The shutter 37
Is opened and closed by an appropriate shutter opening and closing mechanism 38 attached to the side wall 32.

A disk 41 having a diameter slightly smaller than the inner diameter of the cylindrical casing 34 is provided in the stirring tank 40 at a position close to the side wall 32, and the disk 41 is rotatable on the side wall 32 via an appropriate bearing. Is fixed to a support shaft 42 supported by the support shaft 42. The support shaft 42 is connected to a motor 43 via a suitable speed adjusting means (not shown). Further, the disk 4
In FIG. 1, two stirring rods 44a, 44b and 45a, 45b are fixed in the vicinity of the outer peripheral edge thereof, and two stirring rods 44a, 44b and 45a, 45b near the center thereof, respectively, at symmetrical positions with respect to the support shaft 42. As shown in FIG. 1, it extends to the vicinity of the opposing side wall 33. On the other hand, two fixed rods 46a and 46b having a space inside are fixed to the side wall 33 so as to be located in the middle of the rotation locus of the stirring rods 44 and 45.

A flat heater 47 is attached to the inner peripheral wall of the cylindrical casing 34 and the wall surface of the side walls 32, 33 defined by the cylindrical casing 34.
A rod-shaped heater 48 (FIG. 1) is provided in the internal space of the fixed rod 46.
Are inserted, and the flat heater 47 and the rod-shaped heater 48
Are connected to a power supply unit (not shown) via an appropriate circuit.

Below the discharge opening 36 formed in the cylindrical casing 34, a metering / unloading means 50 is provided.
That is, the guiding funnel 5 is located below the discharge opening 36.
1, 52 are located below the funnel 52, and a weighing hopper 53 is provided below the funnel 52 via an appropriate load cell 54.
33 supported. A conveyor 56 connected to a blower 55 is located near the discharge port of the weighing hopper 53. The guide funnels 51 and 52 are provided for the purpose of preventing the processed material in the cylindrical casing 34 from dropping into the measuring hopper 53 at one time.

Further, this apparatus has a control box 100 and a level sensor 1 provided on a hopper 11.
4, 15, the speed control mechanism 26 of the motor 25, the speed control means of the motor 43, the power supply circuit of the flat heater 47 and the rod-shaped heater 48, the load cell 54 of the measuring hopper 53, and the blower 5.
5 and electrically controls the operation of the apparatus.

Next, the operation of this device will be described.
As described above, the accumulated resin foam, which is mainly waste material, is crushed to an appropriate size by a crusher (not shown),
The air is supplied from the inlet 12 into the hopper 11 by a blower. The level of the supplied crushed product is determined by the upper level sensor 15.
If it is detected by, the operation of the blower is stopped and the supply is stopped. A predetermined amount of the pulverized product in the hopper 11 is measured by rotation of the measuring mass 22 driven by the motor 25,
It falls on the guide plate 31 from the delivery side of the measuring mass 22. The fallen crushed product is sent into the stirring tank 40 from the opening 35 formed in the side wall 33, gradually moves along the slope of the guide plate 31, and falls into the stirring tank 40.

Inner peripheral wall and side wall 3 of cylindrical casing 34
At this time, the heater 47 attached to the fixing rods 2 and 33 and the heater 48 inserted into the fixing rod 46 are energized, and the internal space of the stirring tank 40 becomes 100 ° C.
The heating atmosphere is about 00 ° C. In this state, the rotating disk 41 is rotated by driving the motor 43. As a result, the pulverized product of the resin foam material supplied is stirred by the stirring rods 44 and 45.
Due to the interaction between the liquid and the fixing rod 46, the liquid is heated while being substantially uniformly stirred. Due to the stirring under the heating atmosphere, the pulverized product is partially subjected to heat shrinkage from its surface. At the same time, suspended matters such as bubbles formed during the above-mentioned pulverization and broken into thin films or long fibers and gathered in a swirl shape are also thermally shrunk and formed into blocks.

After the stirring process under the heating atmosphere is performed for a predetermined time, the shutter 37 is opened and the processed product is guided to the guide funnel 5.
It is transferred to the weighing hopper 53 via 1 and 52. In the measuring hopper 53, the bulk density of the processed material is measured by the load cell 54, and the measured value is sent to the control box 100. The weighed processed material is transferred from the weighing hopper 53 to the conveyor 56, and transferred from the blower 55 to an appropriate processed material collection point outside the apparatus. Then, when necessary, it is mixed with a new material to form a resin foam product.

If there is a deviation between the measured value and the initial value, control is performed to correct the deviation. There are various methods for correcting the deviation. For example, the correction signal may be sent from the control box 100 to the temperature control mechanism of the heaters 47 and 48 to raise or lower the temperature inside the cylindrical casing 34, or the control mechanism of the shutter 37 may not change the feed temperature. Alternatively, the stirring time may be lengthened or shortened. Furthermore, it is also possible to adjust by controlling the rotation speed of the motor 43. Moreover, you may control by combining each said means.

Although not particularly shown, a flow path switching valve may be provided at the outlet of the blower 55 to form a return path for returning the processed material to the hopper 11 with a bulk density of a predetermined value or less. As the process proceeds, the level of the crushed product in the hopper 11 decreases. When the lower sensor 14 detects the level of the crushed product, the crusher is operated to supply the crushed product into the hopper 11.

Hereinafter, this operation is performed by the control box 1
It is repeated based on the command from 00. By this treatment, the pulverized resin foam is adjusted to a desired bulk density. It will be easily understood that the set bulk specific gravity value can be changed during the operation. The above description is only a description of one embodiment of the method and apparatus of the present invention, and there are many other variations.

For example, the type of the level sensor provided in the hopper 11 is arbitrary, and the level sensor itself is optional. As the fixed amount feeding means provided on the outlet side of the hopper 11, any means can be used as long as it can repeatedly supply a predetermined amount. For example, a supply unit using a shutter plate that opens and closes at regular time intervals may be used.
The guide plate 31 having an upwardly convex cross-sectional shape is provided for the purpose of preventing the pulverized product from suddenly forming a block and being thrown into the cylindrical casing. For example, in the case of a configuration in which a small number of units are supplied many times, a simple flat guide plate may be used.

The number and mounting position of the stirring rod and the fixing rod are also arbitrary, and may be appropriately determined experimentally so as to obtain more uniform stirring of the pulverized product. The shape does not need to be a cylindrical rod as shown in the figure, but may be rectangular or oval. Furthermore, a flat and rod-shaped heater for heating the inside of the cylindrical casing into a heating atmosphere is also shown as an example of the heating means, and may be supplied by supplying dry or humidified high-temperature air to the pulverized product generated at the time of stirring. It is also possible to use frictional heat between comrades or a stirring rod and a crushed product. Also,
They can also be used in appropriate combinations. Especially,
The flat heater 47 can be mounted on the outer wall of the cylindrical casing 34 and the side walls 32, 33, or on both the inner and outer sides. The means for measuring the bulk density with the measuring hopper is also optional, and a conventionally known bulk density measuring method can be appropriately used. In the case of such a pulverized resin foam material, a bulk density measurement method by measuring a light transmission amount can also be used effectively.

[Use Example] Styrofoam foam was pulverized with a pulverizer so as to have an average particle diameter of 3 mm, and the bulk density was measured to be about 0.01 g / cc. The pulverized product is put into the apparatus shown in the drawing, and the temperature in the cylindrical casing is reduced to 15 ° C.
The mixture was stirred at 0 ° C. for 5 minutes. When the bulk density of the agitated product was measured with a measuring hopper, it was about 0.02 g / cc.
And could be. When the bulk density was measured by continuing the stirring for further 5 minutes, it could be about 0.12 g / cc.

[0026]

According to the present invention, the bulk specific gravity of a resin foam pulverized product pulverized by a pulverizer can be easily adjusted to a desired value. When processing a mixture of pulverized materials having different specific gravities, the mixture can be finally adjusted to have a uniform bulk density. As a result, it is possible to reliably perform weight management when molding a product in which the recycled foam material treated according to the present invention and the novel foam material are mixed. Further, since a measured amount of suspended matter contained in the pulverized product can be granulated, clogging does not occur in the steam supply port of the molding machine even when molding is performed for a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a processing apparatus according to the present invention.

FIG. 2 is a diagram illustrating an example of a fixed amount feeding unit.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a partially broken perspective view illustrating a stirring tank.

[Explanation of symbols]

11: hopper, 20: fixed amount supply means for pulverized foam resin, 40: stirring tank, 44, 45: stirring rod, 46: fixed rod, 47, 48: heater, 53: measuring hopper, 54:
Load cell

Claims (2)

(57) [Claims] 1. A foamed resin pulverizer in which a predetermined amount of a foamed resin pulverized product is stirred under a predetermined heating condition for a required time, and the foamed resin pulverized product is partially thermally shrunk during the stirring to adjust the overall bulk density. A method for adjusting the bulk density of a product , further comprising:
Foamed resin pulverized product that has been agitated for a predetermined period of time under constant heating conditions
Take out a part of it and measure its bulk density,
A step of adjusting heating conditions and / or stirring time based on
A method for adjusting the bulk density of a pulverized foamed resin product. 2. A means for quantitatively supplying the pulverized foamed resin, a stirring tank for receiving and stirring the pulverized foamed resin from the quantitative supply means, a stirring means for stirring the pulverized foamed resin in the stirring tank, A bulk means for heating the crushed foamed resin article in the stirring tank, and a measuring means for measuring the crushed foamed resin article which has been stirred and heated, Adjustment device.