JP4878655B2 - Biodegradable container manufacturing method and biodegradable container manufactured by the manufacturing method - Google Patents

Description

  The present invention relates to a biodegradable container manufacturing method and a biodegradable container manufactured by the manufacturing method, and more specifically, a method of manufacturing a biodegradable container by foaming a biodegradable material and the method. Related to biodegradable containers.

  As a prior art related to the present invention, a biodegradable film is preliminarily molded so as to substantially match the shape of a container to be manufactured by a method such as vacuum molding or blow molding. The biodegradable film and biodegradable material are placed in the mold so that the dough-like biodegradable material mainly composed of starch is sandwiched between the biodegradable film, and the biodegradable material is heated and foamed in the mold. A method for producing a biodegradable container is known in which the surface of the foamed base material layer is coated with a biodegradable film simultaneously with the molding of the foamed base material layer by firing (see, for example, Patent Document 1).

  Further, as a related art related to the present invention, a biodegradable material mainly composed of starch is foamed and fired to form a container-shaped foamed base material layer, and the formed foamed base material layer is vacuum-evacuated. Place the biodegradable film that has been preheated on the mold on which it is formed, evacuate it through the foam base layer, and pressurize it from the biodegradable film side by the compressed air method. A method for manufacturing a biodegradable container in which the inner surface of a material layer is covered with a biodegradable film is known (see, for example, Patent Document 2).

  Further, as a prior art related to the present invention, a vacuum suction mechanism and a pressurization mechanism are connected to vapor vent holes formed in a pair of male molds and female molds, respectively, and a dough shape using starch as a main raw material in the female molds. The biodegradable material is put on, the biodegradable film is placed on it, the male mold and the female mold are fitted, the biodegradable material is heated, foamed and baked, and then the female mold is vented A method for producing a biodegradable container is known in which vacuum suction is performed from a hole and pressure is applied from a male vapor vent hole, and the inner surface of the resulting container-like foamed substrate layer is covered with a biodegradable film (for example, And Patent Document 3).

Japanese Patent No. 3961421 Korean Patent No. 10-0548949 JP 2006-21356 A

In response to growing environmental awareness in recent years, such as the reduction of carbon dioxide and the establishment of a resource recycling society, products that do not rely on petroleum resources are also required in the field of disposable containers.
Under such circumstances, biodegradable containers using plant-derived biomass as a raw material have attracted attention. Plant-derived biomass absorbs carbon dioxide in the atmosphere and grows. Therefore, even if carbon dioxide is discharged during biodegradation or incineration after disposal, it is absorbed by the raw material biomass. It was discharged into the atmosphere again, and the total amount of carbon dioxide in the atmosphere does not increase from the total production to disposal. Such a property is called carbon neutral and is an important keyword when considering environmental issues.

  As a biodegradable container using biomass as a raw material, as shown in Patent Documents 1 to 3, the surface of a foamed base material layer obtained by foaming and baking a biodegradable material using starch as a main raw material is used. A coating with a hydrophobic biodegradable film has been proposed. In other words, the surface of the foam base layer is covered with a hydrophobic biodegradable film, so it is excellent in water resistance, and since the foam base layer forms the skeleton of the container, it is lightweight and high in strength. Excellent in properties.

As a method for producing such a biodegradable container, various methods have been proposed as disclosed in Patent Documents 1 to 3.
In the method described in Patent Document 1, the biodegradable material is heated in a mold so that the biodegradable material is sandwiched between two biodegradable films formed in advance so as to substantially match the shape of the container. By foaming and baking, the surface of the foamed base material layer is simultaneously coated with a biodegradable film.
However, a separate process for pre-molding the biodegradable film so as to substantially match the shape of the container is necessary, and it takes time to place the pre-degraded biodegradable film in the mold. .

Further, in the method described in Patent Document 2, a container-shaped foam base material layer that has been foam-molded in advance is placed in a mold that can be evacuated and a preheated biodegradable film is placed thereon. The inner surface of the foamed substrate layer is covered with the biodegradable film by evacuation through the foamed substrate layer and pressurizing from the biodegradable film side by the compressed air method. That is, according to the method described in Patent Document 2, it is possible to eliminate the step of forming the biodegradable film in advance so as to substantially match the shape of the container as in Patent Document 1.
However, it is necessary to separately form a container-shaped foam base material layer in advance, and it takes time and effort to place the pre-formed foam base material layer on the mold.

In the method described in Patent Document 3, the inner surface of a container obtained by evacuation and pressurization through a vapor vent hole is covered with a biodegradable film while foaming and firing a biodegradable material in a mold. However, when the biodegradable material is foamed and baked, if the vacuum is sucked from the vapor vent hole, the biodegradable material is sucked into the vapor vent hole, and the vapor vent hole is closed with the biodegradable material. It becomes impossible.
Further, even if the steam can be vented, the steam vent hole is blocked with the biodegradable material while the manufacturing is repeated, so that the maintenance of the mold is troublesome.

  Thus, each method has room for improvement from the viewpoint of productivity, and a method capable of producing a biodegradable container with higher productivity is required. In addition, in the methods described in Patent Documents 2 and 3, it is necessary to use an adhesive for fixing the biodegradable film to the surface of the foamed base material layer, and the use of such an adhesive is produced by increasing the number of processes. It is not preferable from the viewpoint of not only causing deterioration of properties but also increasing the degree of biomass of the raw material of the biodegradable container.

  Furthermore, in the methods described in Patent Documents 2 and 3, only the inner surface of the biodegradable container is coated with a biodegradable film. From the viewpoint of preservability, it is preferable that both the inner and outer surfaces of the biodegradable container are covered with a biodegradable film as in Patent Document 1.

  The present invention has been made in view of the above circumstances, and is manufactured by a biodegradable container manufacturing method capable of manufacturing a biodegradable container whose surface is coated with a biodegradable film with high productivity and the manufacturing method thereof. An improved biodegradable container is provided.

  The present invention uses a mold for foam molding comprising a pair of male and female molds that can be fitted with a built-in heater and a vacuum evacuation hole for evacuation. The biodegradable film is closely attached to the surface by vacuum drawing and preformed while the biodegradable material is interposed, the male mold and the female mold are fitted, and the biodegradable material is heated in the mold for foaming / A first method for producing a biodegradable container is provided, comprising a step of coating the surface of the base material layer with the biodegradable film simultaneously with the molding of the foam base material layer by firing. is there.

  The present invention also uses a mold for foam molding comprising a pair of male and female molds that can be fitted with a built-in heater and formed with a vacuum evacuation hole for evacuation. A mold in which the male mold and the female mold are fitted with each other by interposing a biodegradable material with a biodegradable film closely attached to the surface of the mold by vacuum drawing and interposing a biodegradable material. The step of coating the surface of the base material layer with the biodegradable film simultaneously with the molding of the foamed base material layer by heating and foaming and firing the biodegradable material in the mold, In the step of fitting, the biodegradable material is disposed above the female mold in a state of being sandwiched between two biodegradable films, and the biodegradable film is male while simultaneously fitting the male mold and the female mold. A biodegradable container characterized by being attached to the surface of a mold and a female mold. Also provides a second method of manufacturing.

According to the first and second manufacturing methods of the biodegradable container according to the present invention, the biodegradable material is interposed while the biodegradable film is brought into close contact with the surfaces of the male mold and the female mold by evacuation. Since the male mold and female mold are fitted together, the biodegradable film preform (pre-molding) and the biodegradable material foam molding can be performed continuously in the same mold and in the same process. Is significantly improved.
In particular, according to the second production method of the present invention, since the biodegradable film and the biodegradable material are supplied simultaneously, the process can be further shortened, and the productivity is further improved.

It is sectional drawing of the biodegradable container manufactured by the manufacturing method which concerns on Embodiment 1 of this invention. It is an enlarged view of the A section of FIG. It is explanatory drawing explaining the taper angle of the trunk | drum of the biodegradable container shown by FIG. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the modification which uses a plug together, when preforming a biodegradable film in the manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention. It is sectional drawing of the biodegradable container manufactured by the manufacturing method which concerns on Embodiment 3 of this invention. It is an enlarged view of the B section of FIG. It is explanatory drawing explaining the taper angle of the trunk | drum of the biodegradable container shown by FIG. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention. It is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention. FIG. 10 is a view corresponding to FIG. 10 showing a modification of the biodegradable container manufactured by the manufacturing method according to Embodiment 3 of the present invention. It is an enlarged view of the C section of FIG. It is explanatory drawing explaining the taper angle of the trunk | drum of the biodegradable container shown by FIG.

  A first method for manufacturing a biodegradable container according to the present invention is for foam molding comprising a pair of male and female molds that can be fitted with a built-in heater and a vacuum suction hole for vacuuming. Using a mold, the male and female molds are fitted to each other by interposing a biodegradable material with a biodegradable film closely attached to the surfaces of the male and female molds by vacuum drawing. The step of covering the surface of the base material layer with the biodegradable film simultaneously with the molding of the foam base material layer by heating and foaming / firing the biodegradable material in a mold in which the die and the female die are fitted It is characterized by providing.

  Further, the second method for producing a biodegradable container according to the present invention is a foam molding comprising a pair of male and female molds that can be fitted with a built-in heater and a vacuum suction hole for vacuuming. Using the mold for, the biodegradable film is adhered to the surface of each of the male mold and the female mold by vacuum drawing, and the male mold and the female mold are fitted with the biodegradable material interposed therebetween while performing the preform. The biodegradable material is heated and foamed and fired in a mold in which the male mold and female mold are fitted, thereby simultaneously forming the foamed base material layer and covering the surface of the base material layer with the biodegradable film. The biodegradable material is disposed above the female mold in a state of being sandwiched between two biodegradable films in the step of fitting the male mold and the female mold, and the biodegradable film is At the same time that the male and female molds are mated, they are in close contact with the male and female surfaces. And characterized in that it is.

  In the first and second manufacturing methods of the biodegradable container according to the present invention, foaming comprising a pair of male and female molds that can be fitted with a built-in heater and a vacuum evacuation hole for vacuuming. The mold for molding is to form a cavity corresponding to the shape of the container at the time of fitting, and appropriately release gas and water vapor generated when the biodegradable material is heated and foamed in the cavity to the outside. It means a mold configured to be able to. The heater is preferably provided in both the male mold and the female mold in order to manage the mold at a desired temperature. Further, at least one, preferably a plurality of vacuum holes are formed in the male mold and the female mold so that the biodegradable film can be brought into close contact with the surfaces of the male mold and the female mold, respectively.

In the first and second manufacturing methods of the biodegradable container according to the present invention, the biodegradable film may be a biodegradable film that can impart water resistance to the surface of the biodegradable container, and is particularly limited. For example, a film formed of a biodegradable plastic can be mentioned. The biodegradable film is preferably biaxially stretched from the viewpoint of heat resistance.
Although the thickness of a biodegradable film is not specifically limited, For example, it can be set as about 20-100 micrometers. If the thickness is less than about 20 μm, the mechanical strength of the film is insufficient, and the film is easily broken when stretched, resulting in a decrease in yield. On the other hand, when it becomes thicker than about 100 μm, the mechanical strength is sufficiently obtained, but it becomes difficult to stretch and the productivity is deteriorated. Moreover, it is not preferable also from a viewpoint of material cost.
For this reason, the thickness of the biodegradable film can be said to be an appropriate range of about 20 to 100 μm.

  Examples of biodegradable plastics include 3-hydroxybutyric acid-3-hydroxyvaleric acid copolymer, poly-p-hydroxybenzaldehyde (PHB), polybutylene succinate (PBS), polycaprolactone (PLC), and cellulose acetate. (PH) polymer, polyethylene succinate (PESu), polyester amide, modified polyester, polylactic acid (PLA), matterby (registered trademark, Novamont, Italy: polyvinyl alcohol resin having starch as a main component and biodegradability And aliphatic polyester-based resins as subcomponents), and so-called “biodegradable plastics” such as cellulose / chitosan composites. Only one kind of these biodegradable plastics may be used, or two or more kinds of composites may be used. In addition, these biodegradable plastics may contain auxiliary raw materials such as biodegradable plasticizers and fillers.

  In the first and second manufacturing methods of the biodegradable container according to the present invention, the biodegradable material is a material for the foam base layer that forms the skeleton of the biodegradable container, and is a foam molding die. It means the one adjusted so that it can be molded.

In the first and second manufacturing methods of the biodegradable container according to the present invention, the step of heating the biodegradable material in the mold applies a high frequency to the biodegradable material through the male mold and the female mold. And a step of dielectric heating.
According to such a configuration, in addition to heating from the mold, high frequency is applied to the biodegradable material and dielectric heating is performed. Therefore, the biodegradable material itself can be efficiently heated and required for foaming and firing. Time can be greatly reduced. This greatly improves the productivity of the biodegradable container.

In the first and second manufacturing methods of the biodegradable container according to the present invention, the step of heating the biodegradable material in the mold heats the biodegradable material while continuing to vacuum in the mold. It may be a step of foaming and baking.
According to such a configuration, even if there is a depressed portion where the biodegradable film is difficult to adhere to the mold, the biodegradable material is foamed while the biodegradable film is securely adhered to the portion. From the viewpoint of shape reproducibility, the moldability of the biodegradable container is improved, and a biodegradable container having a desired shape can be manufactured with a high yield.

In the second method for producing a biodegradable container according to the present invention, the two biodegradable films may be coated with an inorganic powder on their opposing surfaces.
According to such a configuration, two biodegradable films can be prevented from sticking to each other during the manufacturing process of the biodegradable container.
Here, examples of the inorganic powder include titanium dioxide and talc powders.

  In the first and second manufacturing methods of the biodegradable container according to the present invention, the biodegradable material may be a kneaded product obtained by kneading at least starch, pulp and water.

Here, starch means starch or a derivative thereof, and is not particularly limited. For example, potato, corn, tapioca, rice, wheat, sweet potato, and other agricultural products that are produced worldwide as main grains. The starch obtained from can be mentioned, The thing manufactured from the specific agricultural product may be used, and the thing manufactured from the several agricultural products may be mixed.
Further, the starch derivatives mentioned above refer to those obtained by modifying starch within a range that does not inhibit biodegradability, and examples thereof include pregelatinized starch, crosslinked starch, and modified starch.
Furthermore, a mixture obtained by mixing the above-mentioned unmodified starch and the above-mentioned starch derivative may be used.

  The pulp means an aggregate of plant-derived fibers and is not particularly limited, and examples thereof include wood pulp and non-wood pulp.

In the above configuration in which the biodegradable material is composed of a kneaded material obtained by kneading at least starch, pulp and water, the biodegradable material may contain a colorant.
According to such a structure, since the light transmittance of the manufactured biodegradable container is lowered and the light shielding property is improved, the deterioration of the flavor due to photooxidation can be prevented when food containing fats and oils is accommodated.
In addition, a coloring agent means the pigment | dye for coloring a biodegradable container here, Although it does not specifically limit, For example, a food coloring agent can be used. Examples of food coloring agents include Atoner pigment, gardenia yellow pigment, cochineal pigment, lac pigment, red cabbage pigment, red radish pigment, grape juice pigment, grape skin pigment, purple potato pigment, purple corn pigment, elderberry pigment, cacao. Examples thereof include natural colorants such as pigments, cucumber pigments, onion pigments, tamarind pigments, safflower yellow pigments, turmeric pigments, beet red, red grape pigments, red grape yellow pigments, gardenia blue pigments, gardenia red pigments.

From another point of view, the present invention is a biodegradable container manufactured by the first or second method for manufacturing a biodegradable container according to the present invention, comprising an opening and a bottom, and an opening and a bottom. The body part also provides a biodegradable container having a shape that tapers at a predetermined taper angle from the opening part toward the bottom part.
Here, the taper angle refers to an angle formed by the central axis of the biodegradable container and the surface of the body portion.

In the biodegradable container according to the present invention, the taper angle may be 10 ° or less.
In addition, the taper angle should just be 10 degrees or less here, The lower limit is not specifically limited, For example, it can be set as about 6 degrees.

  Such a biodegradable container has a shape in which the body portion is cut off with respect to the bottom, but it is assumed that the body portion in the above-described shape is formed only by a pressing force when fitting the male mold and the female mold. If an attempt is made to stretch the biodegradable film along the line, the stretch rate of the biodegradable film is locally increased at the portion corresponding to the body portion, and the biodegradable film is torn due to excessive load. End up.

However, in the first and second manufacturing methods of the biodegradable container according to the present invention, when the male mold and the female mold are fitted, the biodegradable film is evacuated on the surfaces of the male mold and the female mold, respectively. Preform with close contact.
At the time of preforming by evacuation, the biodegradable film adheres to the surfaces of the male and female molds while being stretched entirely by the negative pressure generated between the biodegradable film and the male and female molds.
For this reason, compared with the case where the biodegradable film is stretched only by the pressing force when the male mold and the female mold are fitted, the biodegradable film is stretched as a whole by using a vacuum-drawn preform. It is possible to prevent the biodegradable film from being broken due to an excessive load.

Therefore, by utilizing the first and second manufacturing methods of the biodegradable container according to the present invention, the biodegradable film can be used even in the biodegradable container having the trunk portion having the above-described shape. It is possible to stretch the film so as to match the shape.
That is, the first and second production methods of the biodegradable container according to the present invention are effective not only for improving the productivity of the biodegradable container but also for stretching the biodegradable film without difficulty. A wide range of shapes is possible, from a bowl-like shape with a large taper angle to a bucket-like shape with a small taper angle.
In general, the longer the container is in a vertically long shape, the smaller the taper angle of the body part in order to secure the diameter of the bottom part. However, the first and second manufacturing methods of the biodegradable container according to the present invention are described above. Since it can respond also to the trunk | drum of a sharp shape with a small taper angle, it can utilize suitably also for manufacture of the biodegradable container which has a vertically long shape.

  Hereinafter, the manufacturing method of the biodegradable container which concerns on embodiment of this invention based on drawing is demonstrated. In addition, in the several embodiment demonstrated below, the same code | symbol is attached | subjected and demonstrated to the same member.

Embodiment 1
The manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention is demonstrated based on FIGS. 1 is a cross-sectional view of a biodegradable container manufactured by the manufacturing method according to Embodiment 1 of the present invention, FIG. 2 is an enlarged view of part A of FIG. 1, and FIG. 3 is a view of the biodegradable container shown in FIG. FIG. 4 to FIG. 6 are process diagrams for explaining a method for manufacturing a biodegradable container according to the first embodiment, and FIG. 7 is a method for manufacturing a biodegradable container according to the first embodiment. It is explanatory drawing which shows the modification which uses a plug when preforming a biodegradable film.

As shown in FIGS. 1 and 2, the biodegradable container 1 manufactured by the manufacturing method according to Embodiment 1 of the present invention includes a foam base material layer 2 and a foam base material that form a skeleton of the biodegradable container 1. It consists of a hydrophobic biodegradable film 3 that covers both the inner and outer surfaces of the layer 2.
The biodegradable container 1 has an opening 1a and a bottom 1b, and a body 1c extending between the opening 1a and the bottom 1b. As shown in FIG. 3, the body 1c has a shape that tapers at a predetermined taper angle θ1 from the opening 1a toward the bottom 1b. Here, the taper angle θ1 is an angle formed by the center line (center axis) CL of the biodegradable container 1 and the surface of the body portion 1c.

In the present embodiment, the diameter D1 of the opening 1a is 151 mm, the height H1 from the bottom 1b to the opening 1a is 75 mm, the taper angle θ1 is 10.5 °, and the height H1 from the bottom 1b to the opening 1a. Is 50% of the diameter D1 of the opening.
By covering both the inner and outer surfaces of the foam base material layer 2 with the biodegradable film 3, the biodegradable container 1 is excellent in moisture resistance and long-term storage, and the foam base material layer 2 is excellent. Due to its heat insulation properties, it can also be used with hot water.

Hereinafter, the manufacturing method of the biodegradable container 1 shown by FIG. 1 is demonstrated based on FIGS.
In this embodiment, as shown in FIG. 4A, a pair of male mold 4 and female mold 5 for forming a cavity 9 (see FIG. 5D) corresponding to the shape of the container to be molded, A mold 6 for foam molding is used. The male mold 4 and the female mold 5 incorporate an electric heater (not shown), and both are maintained at about 130 to 175 ° C. in the following steps. Further, the male mold 4 and the female mold 5 are formed with a plurality of evacuation holes 4a and 5a for evacuation, respectively.

First, as shown in FIG. 4A, two biodegradable films 3 are placed between a male mold 4 and a female mold 5 while being stretched on a frame 8. One of the two biodegradable films 3 is disposed below the male mold 4 and the other is disposed above the female mold 5.
Although not shown, each biodegradable film 3 is exposed to radiant heat generated from a plate heater at about 400 to 500 ° C. for about 3 to 12 seconds before being placed between the male mold 4 and the female mold 5. And preheated to about 100-175 ° C.
In the present embodiment, the biodegradable film 3 is made of a modified polyester, which is a kind of biodegradable plastic, and has a thickness of about 50 μm.

  Next, as shown in FIG. 4 (b), the frame body 8 disposed below the male mold 4 is raised toward the male mold 4, and the frame body 8 disposed above the female mold 5 is moved to the female mold 4. Lower toward mold 5. When the biodegradable film 3 stretched on the frame 8 comes into contact with the male mold 4 and the female mold 5, evacuation is started through the vacuum evacuation holes 4 a and 5 a of the male mold 4 and the female mold 5, respectively. When the evacuation is started, strong negative pressure is generated between the biodegradable film 3 and the male mold 4 and the female mold 5, and the biodegradable film 3 has a male mold 4 and a female mold 5 within a short time. Are closely adhered to the surface of each of them, and are preformed (pre-molded) following the shapes of the male mold 4 and the female mold 5. FIG. 4B illustrates a state immediately before the biodegradable film 3 is in close contact with the surfaces of the male mold 4 and the female mold 5.

  Instead of raising and lowering the frame body 8 toward the male mold 4 and the female mold 5, respectively, the male mold 4 and the female mold 5 may be lowered and raised toward the frame body 8, respectively. The male mold 4 and the female mold 5 may be lowered and raised while raising and lowering 8, and the moving method is not particularly limited as long as the biodegradable film 3 can be brought into contact with the male mold 4 and the female mold 5.

  Further, when the biodegradable film 3 is brought into close contact with the surfaces of the male mold 4 and the female mold 5 by vacuuming, a concave plug 10 and a convex plug 11 as shown in FIG. 7 may be used. By using the concave plug 10 and the convex plug 11, the biodegradable film 3 can be reasonably aligned with the surfaces of the male mold 4 and the female mold 5, and the biodegradable film 3, the male mold 4, and the female mold 5 The biodegradable film 3 can be preformed neatly by exerting the negative pressure generated during the period more effectively.

Next, as shown in FIG. 5C, a biodegradable material 7 that is a material of the foam base material layer 2 (see FIG. 2) is supplied to the bottom of the female mold 5. Since the biodegradable film 3 is in close contact with the surface of the female mold 5, the biodegradable material 7 is placed on the biodegradable film 3.
The biodegradable material 7 is a dough-like kneaded material in which starch is mixed with a melt of pulp, polyvinyl alcohol (PVA), and water and then heated to α. An appropriate amount of titanium dioxide may be mixed with the starch so as to exhibit optimum properties as a material for the biodegradable container.

Next, as shown in FIG. 5 (d), the male mold 4 is lowered and fitted with the female mold 5, and the supplied biodegradable material 7 is pressurized and filled into the cavity 9. At this time, since the biodegradable film 3 is in close contact with the surfaces of the male mold 4 and the female mold 5 by vacuuming, and the preform is made, the male mold 4 and the female mold 4 are not considered without breaking the biodegradable film 3. The mold 5 can be fitted at a high speed, and the productivity is significantly improved as compared with the case where the biodegradable film 3 is stretched only by fitting the male mold 4 and the female mold 5 without using vacuuming. To do.
In this embodiment, the male mold 4 is lowered and fitted with the female mold 5. However, of course, the female mold 5 may be raised and fitted with the male mold 4, or the male mold 4 is lowered. The female mold 5 may be raised while being fitted.
In this embodiment, the fitting speed of the male mold 4 and the female mold 5 (speed at which the male mold 4 and the female mold 5 approach) can be set to 320 mm / second.

  When the male mold 4 and the female mold 5 are fitted, the biodegradable material 7 fully filled in the cavity 9 is heated for about 130 to 210 seconds by the mold 6 maintained at about 130 to 175 ° C. The biodegradable material 7 is fired while being steam-foamed by this heating to form the foamed substrate layer 2. In addition, the biodegradable film 3 that has been subjected to heat and pressure in the mold during foaming / firing adheres to the fine irregularities formed on the surface of the foam base material layer 3 by an anchor effect, and the foam base material layer Both the inner surface and the outer surface of 2 are coated with the biodegradable film 3, respectively. No adhesive is required to coat both the inner and outer surfaces of the foam base material layer 2 with the biodegradable film 3, and the biodegradable film 3 is formed by the anchor effect of pressurization and heating only by the anchor effect. Adheres to the surface.

Although not shown in the drawing, the portion of the mold 6 corresponding to the opening edge 1d (see FIG. 1) of the container 1 is for releasing water vapor generated during the foaming / firing of the biodegradable material 7 from the cavity 9 to the outside. Vapor vent holes are formed.
The size of the hole for removing the vapor is appropriately set according to the moisture value of the biodegradable material 7 so that the internal pressure in the cavity 9 is appropriately maintained and good foaming and firing are performed.

Finally, as shown in FIG. 6 (e), the mold 6 is opened, and the foamed base material layer 2 in which both the inner surface and the outer surface are coated with the biodegradable film 3 is taken out together with the frame body 8. When cutting for each container, the biodegradable container 1 shown in FIG. 1 is obtained.
The biodegradable container 1 manufactured in this way is not particularly colored, and its color is almost white reflecting the color of the biodegradable material 7.

Thus, according to the manufacturing method of the biodegradable container according to Embodiment 1 of the present invention, the preform of the biodegradable film 3 and the foaming / firing of the biodegradable material 7 are continuously performed using the same mold 6. Therefore, productivity is remarkably improved as compared with the conventional method in which the preform of the biodegradable film and the foamed base material layer are separately formed.
In addition, since the biodegradable material 7 is supplied in a state where the biodegradable film 3 is in close contact with the surfaces of the male mold 4 and the female mold 5, the vacuum pulling holes 4a and 5a of the male mold 4 and the female mold 5 are formed. Maintenance of the mold 6 is easy without being blocked by the degradable material 7.

Embodiment 2
The manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention is demonstrated based on FIG. 8 and FIG. 8 and 9 are process diagrams illustrating a method for producing a biodegradable container according to Embodiment 2 of the present invention.

  In the second embodiment, the manufacturing method according to the first embodiment is shortened, and the yield is improved while further improving the productivity. In addition, the biodegradable container manufactured by the manufacturing method of Embodiment 2 has the same configuration as the biodegradable container 1 manufactured in Embodiment 1 (see FIGS. 1 and 2).

In the second embodiment, as shown in FIG. 8 (a), a mold 6 comprising a male mold 4 and a female mold 5 similar to those used in the first embodiment is used, and the biodegradable material 7 is framed. 8 is placed above the female mold 5 in a state of being sandwiched between two biodegradable films 3 stretched between the two. That is, in Embodiment 2, the biodegradable film 3 and the biodegradable material 7 are simultaneously supplied to the mold 6.
The two biodegradable films 3 are preliminarily coated with titanium dioxide or talc powder on their opposing surfaces in order to prevent the biodegradable films 3 from sticking to each other in the manufacturing process.
Although not shown, the biodegradable film 3 sandwiching the biodegradable material 7 is exposed to radiant heat emitted from a plate heater at about 400 to 500 ° C. for about 3 to 12 seconds before being placed above the female mold 5. And preheated to about 100-175 ° C.

  Next, as shown in FIG. 8 (b), the male mold 4 and the female mold 5 are fitted together, and at the same time, vacuuming is performed through the vacuum pulling holes 4a and 5a of the male mold 4 and the female mold 5, thereby The male mold 4 and the female mold 5 are completely fitted as shown in FIG. 9 (c) while preforming the degradable film 3 in close contact with the surfaces of the male mold 4 and the female mold 5, respectively. FIG. 8B illustrates a state just before the biodegradable film 3 is in close contact with the surfaces of the male mold 4 and the female mold 5.

As shown in FIG. 9C, when the male mold 4 and the female mold 5 are completely fitted, the raw material in the cavity 9 is passed from the high frequency oscillator 12 through the male mold 4 and the female mold 5 serving as load electrode portions. Application of high frequency to the degradable material 7 is started, and the biodegradable material 7 is dielectrically heated for about 4 to 15 seconds.
The high-frequency oscillator 12 is connected to the male mold 4 and the female mold 5 that are load electrode portions via a matching circuit 13 having variable inductance and capacitance, and impedance matching is performed on the biodegradable material 7 that is an object to be heated. A high frequency is applied while taking.

When the biodegradable material 7 itself in the cavity 9 generates heat due to the dielectric heating, the biodegradable material is rapidly foamed and fired in the cavity 9 to form the container-like foamed base material layer 2 and its surface. Is covered with the biodegradable film 3.
As in the first embodiment, the biodegradable film 3 is in close contact with the surface of the foamed base material layer 2 only by the anchor effect by pressurization and heating, and no adhesive is required.

Note that the vacuuming through the vacuuming holes 4a and 5a of the male mold 4 and the female mold 5 is performed by the biodegradable material 7 in the cavity 9 of the mold 6 after the male mold 4 and the female mold 5 are fitted. Continue until heated and baked.
By continuing the evacuation, the biodegradable film 3 comes into close contact with the mold 6 and the cavity 9 as designed is configured. Therefore, the biodegradable material 7 is poured into the cavity 9 without being obstructed by the biodegradable film 3 and is foam-molded, so that a molded product that reproduces the curvature and angle according to the product design drawing can be obtained.
Specifically, for example, as represented by the inner edge portion 1e of the biodegradable container 1 shown in FIG. The biodegradable film 3 can be neatly adhered to a portion where the biodegradable film 3 is difficult to adhere, and the shape of the mold 6 is well reproduced in the shape of the biodegradable container 1.
Thereby, the reproducibility of the shape is improved, and the biodegradable container 1 having a desired shape can be manufactured with a high yield.

  Finally, as shown in FIG. 9 (d), the mold 6 is opened, and the foamed base material layer 2 having both the inner surface and the outer surface covered with the biodegradable film 3 is taken out together with the frame body 8, When cutting for each container, a biodegradable container similar to the biodegradable container 1 shown in FIG. 1 is obtained. Other manufacturing conditions such as the material and thickness of the biodegradable film 3 and the blending of the biodegradable material 7 are the same as those in the first embodiment.

  In the second embodiment, the biodegradable material 7 is disposed above the female mold 5 with the two biodegradable films 3 sandwiched between the two biodegradable films 3. Can supply. For this reason, a production process is shortened rather than the method of supplying the biodegradable material 7 separately after the preform of the biodegradable film 3 like Embodiment 1. FIG.

  In the first embodiment, the biodegradable material 7 that contacts the bottom of the female mold 5 after the biodegradable material 7 is supplied to the bottom of the female mold 5 and before the male mold 4 and the female mold 5 are fitted together. However, in Embodiment 2, since the heating of the biodegradable material 7 is started after the male mold 4 and the female mold 5 are fitted, the biodegradable material is heated. It is possible to prevent a part of the material 7 from being heated before other parts, and to suppress the occurrence of uneven baking.

Furthermore, in addition to heating from the mold 6, high frequency is applied to the biodegradable material 7 to perform dielectric heating, so that the biodegradable material 7 can be foamed and fired in a short time, and the biodegradable material 7 The time required for foaming and firing can be greatly reduced.
Moreover, the reproducibility of the shape is improved by continuing the evacuation while the biodegradable material 7 is heated.
With these preferable effects, the manufacturing method according to the second embodiment can further improve productivity and yield.

Embodiment 3
The manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention is demonstrated based on FIGS. 10 is a cross-sectional view of a biodegradable container manufactured by the manufacturing method according to Embodiment 3 of the present invention, FIG. 11 is an enlarged view of part B of FIG. 10, and FIG. 12 is a trunk of the biodegradable container shown in FIG. Explanatory drawing explaining the taper angle of a part, FIGS. 13-15 is process drawing explaining the manufacturing method of the biodegradable container which concerns on Embodiment 3. FIG.

As shown in FIGS. 10 and 11, the biodegradable container 21 manufactured by the manufacturing method according to Embodiment 3 of the present invention is the same as the biodegradable container 1 (see FIG. 1) according to Embodiment 1 described above. Similarly, it is comprised from the foaming base material layer 22 which makes | forms frame | skeleton of the biodegradable container 21, and the hydrophobic biodegradable film 3 which coat | covers the surface of both the inner surface of the foaming base material layer 22, and an outer surface.
The biodegradable container 21 has an opening 21a and a bottom 21b, and a body 21c that extends between the opening 21a and the bottom 21b. As shown in FIG. 12, the body portion 21c has a shape that tapers at a predetermined taper angle θ2 from the opening portion 21a toward the bottom portion 21b. Here, the taper angle θ2 is an angle formed by the center line (center axis) CL of the biodegradable container 21 and the surface of the trunk portion 21c.

In Embodiment 3, the diameter D2 of the opening 21a is 103 mm, the height H2 from the bottom 21b to the opening 21a is 90 mm, the taper angle θ2 is 7 °, and the height H2 from the bottom 21b to the opening 21a is the opening. It is 87% of the diameter D2 of the portion 21a.
On the other hand, in the biodegradable container 1 according to the first embodiment (see FIGS. 1 and 3), the diameter D1 of the opening 1a is 151 mm, the height H1 from the bottom 1b to the opening 1a is 75 mm, and the taper. The angle θ1 is 10.5 °, and the height H1 from the bottom 1b to the opening 1a is 50% of the diameter D1 of the opening 1a.

  From the comparison of these numerical values, the biodegradable container 21 according to the third embodiment has a vertically long shape in which the body portion 21c stands up with respect to the bottom portion 21b than the biodegradable container 1 according to the first embodiment. I understand that.

  In addition, the biodegradable container 21 according to the third embodiment is colored brown by a colorant, and has a lower light transmittance and higher light shielding properties than the substantially white biodegradable container 1 according to the first embodiment. Yes. This is advantageous in suppressing the deterioration of flavor due to photooxidation when containing foods containing fats and oils.

In order to confirm the effect of suppressing the photo-oxidation due to coloring, a confectionery obtained by cooking a potato shaped into a stick shape with cooking oil was used as the uncolored biodegradable container 1 according to the first embodiment and the colored raw food according to the third embodiment. After being housed in the decomposable container 21, the openings 1a and 21a were sealed with a paper lid coated with an aluminum foil.
Prepare several similar ones, place them on a table placed in a room kept at a room temperature of about 25 ° C (humidity about humidity), and continue to irradiate light with an illuminance of about 1500 lux from a fluorescent lamp, The change in peroxide value was measured every month for 3 months. The measurement results are as shown in Table 1 below.

As is clear from Table 1, the peroxide value of the confectionery housed in the colored biodegradable container 21 according to Embodiment 3 was housed in the uncolored biodegradable container 1 according to Embodiment 1. It is significantly lower than the confectionery peroxide value.
For this reason, it turns out that the colored biodegradable container 21 which concerns on Embodiment 3 has a suitable performance, when preserving the foodstuff containing fats and oils.
In addition, in the measurement result of Embodiment 3, the value of the peroxide value after 3 months is slightly lower than the value after 2 months, but these measured values are actually measured values, and depend on individual differences of the stored confectionery. It is considered a thing.

  Hereinafter, the manufacturing method of the biodegradable container which concerns on Embodiment 3 is demonstrated based on FIGS. The manufacturing method of the biodegradable container according to Embodiment 3 is basically the same as the manufacturing method of the biodegradable container according to Embodiment 2, but the method of preheating the biodegradable film 3 is changed and manufactured. The time is further shortened.

First, as shown in FIG. 13A, a pair of hot plates 31 in a state where two biodegradable films 3 stretched on a frame 28 are sandwiched with a biodegradable material 27 therebetween. 32.
As in the second embodiment, the two biodegradable films 3 are preliminarily coated with titanium dioxide or talc powder on their opposing surfaces in order to prevent them from sticking to each other in the manufacturing process.
The biodegradable material 27 is basically the same as the biodegradable material 7 used in the first embodiment. However, a colorant for coloring the biodegradable container 21 brown is approximately 0.7 wt. % Blended at a blending ratio. The biodegradable film 3 is the same as that used in the first embodiment.

Next, as shown in FIG. 13B, the biodegradable film 3 is sandwiched between the pair of hot plates 31 and 32 for about 1 second.
The pair of hot plates 31 and 32 has a surface temperature of about 170 ° C., and the biodegradable film 3 is quickly preheated to about 165 to 170 ° C. by directly contacting the hot plates 31 and 32.

As shown in FIGS. 13 (a) and 13 (b), the pair of hot plates 31, 32 are sandwiched between two biodegradable films 3 when the biodegradable film 3 is sandwiched. Recesses 31a and 32a are formed at positions corresponding to the biodegradable material 27 so that the degradable material 27 is not crushed.
For this reason, when the biodegradable film 3 is sandwiched between the pair of heat plates 31, 32, the biodegradable material 27 is accommodated in the recesses 31a, 32a of the heat plates 31, 32, and the biodegradable material 27 has its shape without being crushed. Only the biodegradable film 3 is selectively preheated while maintaining the above.

  Next, as shown in FIG. 14C, the two preheated biodegradable films 3 are placed above the female mold 25 together with the biodegradable material 27 sandwiched between them. In addition, although the metal mold | die 26 used in Embodiment 3 has a shape corresponding to the vertically long biodegradable container 21, it has a structure similar to the metal mold 6 used in Embodiment 1. That is, the male mold 24 and the female mold 25 constituting the mold 26 each incorporate an electric heater (not shown), and a plurality of vacuum holes 24a and 25a are formed.

Next, as shown in FIG. 14D, evacuation is started through the evacuation holes 24a and 25a of the male mold 24 and the female mold 25 at the same time as the male mold 24 and the female mold 25 are fitted. .
At this time, a strong negative pressure is generated between the biodegradable film 3 and the surfaces of the male mold 24 and the female mold 25, and the biodegradable film 3 is stretched as a whole while being stretched as a whole. 24 and female mold 25 are in close contact with each other to form a preform. FIG. 14 (d) depicts a state just before the biodegradable film 3 is in close contact with the surfaces of the male mold 24 and the female mold 25.
Since the biodegradable film 3 is stretched as a whole by evacuation, compared to the case where the biodegradable film 3 is stretched only by the pressing force from the male mold 24 and the female mold 25, it is difficult to apply an excessive load locally and is torn. A beautiful preform without any problems.

Next, as shown in FIG. 15 (e), when the male mold 24 and the male mold 24 are completely fitted, the high frequency oscillator 12 passes through the male mold 24 and the female mold 25 serving as load electrode portions to enter the cavity 29. Application of a high frequency to the biodegradable material 27 is started, and the biodegradable material 27 is dielectrically heated for about 4 to 15 seconds.
The point that the high frequency is applied to the biodegradable material 27 that is the object to be heated while impedance matching is performed by the matching circuit 13 is the same as in the second embodiment.

When the biodegradable material 27 itself in the cavity 29 generates heat due to the dielectric heating, the biodegradable material 27 is quickly foamed and fired in the cavity 29 to form the container-like foamed base material layer 22 and The surface is covered with the biodegradable film 3.
As in the first embodiment, the biodegradable film 3 adheres to the surface of the foamed base material layer only by the anchor effect by pressurization and heating, and therefore no adhesive is required. Further, evacuation is continued until the baking of the biodegradable material 27 is completed as in the second embodiment.

  Finally, as shown in FIG. 15 (f), the male mold 24 and the female mold 25 are unfitted to open the mold 26, and both the inner and outer surfaces are covered with the biodegradable film 3. When the foamed base material layer 22 is taken out together with the frame 28 and the excess biodegradable film 3 is cut, a vertically long biodegradable container 21 shown in FIG. 10 is obtained. Other manufacturing conditions such as the temperature of the mold 26 and the fitting speed between the male mold 24 and the female mold 25 are the same as those in the first embodiment.

  In the third embodiment, the biodegradable film 3 is entirely stretched without difficulty even in a vertically long container having a small taper angle θ2 as shown in FIGS. Can be made.

Modification of Embodiment 3 A modification of the biodegradable container manufactured by the manufacturing method according to Embodiment 3 of the present invention will be described with reference to FIGS. 16 is a view corresponding to FIG. 10 of a biodegradable container according to a modification, FIG. 17 is an enlarged view of a portion C of FIG. 16, and FIG. 18 is an explanatory diagram for explaining the taper angle of the trunk of the biodegradable container shown in FIG. FIG.

As shown in FIGS. 16 and 17, the biodegradable container 41 according to the modified example is a foamed base material that forms the skeleton of the biodegradable container 41 as in the above-described biodegradable container 21 (see FIG. 10). It is comprised from the layer 42 and the hydrophobic biodegradable film 3 which coat | covers both the inner surface of the foaming base material layer 42, and an outer surface.
The biodegradable container 41 has an opening 41a and a bottom 41b, and a body 41c extending between the opening 41a and the bottom 41b. As shown in FIG. 18, the body 41c has a shape that tapers from the opening 41a toward the bottom 41b at a predetermined taper angle θ3. Here, the taper angle θ3 is an angle formed by the center line (center axis) CL of the biodegradable container 41 and the surface of the body portion 41c.

In the biodegradable container 41 according to the modification, the diameter D3 of the opening 41a is 151 mm, the height H3 from the bottom 41b to the opening 41a is 75 mm, the taper angle θ3 is 10 °, and from the bottom 41b to the opening 41a. The height H3 is 50% of the diameter D3 of the opening 41a.
The biodegradable container 41 according to the modified example has a taper angle θ3 (see FIG. 18) of the trunk portion 41c as compared to the biodegradable container 1 according to the first embodiment (see FIG. 1) having a bowl-shaped shape. The body portion 41c is small and has a bucket shape that is slightly cut from the bottom portion 41b.
The biodegradable container 41 which concerns on a modification can be manufactured by the method similar to the biodegradable container 21 shown by FIG.

Comparative Example 1
In Comparative Example 1, a biodegradable container (not shown) having the same shape as that of the biodegradable container 1 according to Embodiment 1 (see FIG. 1) was manufactured without performing a preform by vacuuming.
That is, in Comparative Example 1, the biodegradable film 3 was stretched only by the pressing force from the male mold 4 and the female mold 5.
However, considering the load on the biodegradable film 3, the fitting speed of the male mold 4 and the female mold 5 (speed at which the male mold and the female mold approach) is set to 7 mm / second, which is set much slower than that of the first embodiment. did. Other conditions are the same as in the first embodiment.
As a result, the biodegradable film 3 was not broken, and the obtained biodegradable container had no particular problem.

Comparative Example 2
In Comparative Example 2, a biodegradable container (not shown) having the same shape as the biodegradable container 21 (see FIG. 10) according to Embodiment 3 was manufactured without performing a preform by vacuuming.
That is, in Comparative Example 2, the biodegradable film 3 was stretched only by the pressing force from the male mold 24 and the female mold 25.
However, considering the load applied to the biodegradable film 3, the fitting speed of the male mold 24 and the female mold 25 (speed at which the male mold and the female mold approach) is set to 7 mm / second, which is set much slower than that of the third embodiment. did. Other conditions are the same as in the third embodiment.
As a result, tearing occurred in the biodegradable film 3 in a portion corresponding to the body portion, and a good biodegradable container could not be obtained.

Comparative Example 3
In Comparative Example 3, a biodegradable container (not shown) having the same shape as that of the biodegradable container 41 (see FIG. 16) according to the modified example of Embodiment 3 was manufactured without performing preforming by vacuuming.
That is, in Comparative Example 3, the biodegradable film 3 was stretched only by the pressing force from the male mold and the female mold.
However, in consideration of the load applied to the biodegradable film 3, the fitting speed between the male mold and the female mold (the speed at which the male mold and the female mold approach each other) was set to 7 mm / second, which was set much slower than that of the third embodiment. Other conditions are the same as in the third embodiment.
As a result, tearing occurred in the biodegradable film 3 in a portion corresponding to the body portion, and a good biodegradable container could not be obtained.

From the results of Comparative Examples 1 to 3, when the taper angles θ1, θ2, and θ3 (see FIGS. 3, 12, and 18) of the body portion are 10 ° or less, the biodegradable film 3 of the body portion corresponds to the body portion. It can be seen that the stretch ratio exceeds the allowable amount, and the biodegradable film 3 is torn by an excessive load.
For this reason, like the manufacturing methods according to Embodiments 1 to 3 of the present invention, it is effective to use a preform by evacuation in order to stretch the biodegradable film 3 without difficulty, and is an effective means. It turns out that it becomes.

1, 21, 41 Biodegradable containers 1a, 21a, 41a Openings 1b, 21b, 41b Bottoms 1c, 21c, 41c Body 1d Open edges 1e Inner edges 2, 22, 42 Foamed base material layer 3 Biodegradable Films 4, 24 Male molds 4a, 5a, 24a, 25a Vacuum suction holes 5, 25 Female molds 6, 26 Mold 7, 27 Biodegradable material 8, 28 Frame body 9, 29 Cavity 10 Concave plug 11 Convex plug 12 High-frequency oscillator 13 matching circuit

Claims (5)

A mold for foam molding consisting of a pair of matable male and female molds with a built-in heater and vacuum evacuation holes for evacuation is used. A biodegradable film is placed in close contact by vacuum pulling and a biodegradable material is interposed to fit the male mold and the female mold, and biodegradability is achieved in a mold in which the male mold and the female mold are fitted. In the above-described step of fitting the male mold and the female mold, a step of coating the surface of the base material layer with the biodegradable film simultaneously with the molding of the foam base material layer by heating and foaming and firing the material. The biodegradable material is disposed above the female mold in a state of being sandwiched between two biodegradable films coated with inorganic powder on the opposite surface, and the biodegradable film is fitted with a male mold and a female mold. It is characterized in that it can be brought into close contact with the male and female surfaces at the same time. Method for producing a biodegradable container that. 2. The biodegradable container according to claim 1, wherein the step of heating the biodegradable material in the mold includes a step of dielectrically heating the biodegradable material by applying a high frequency to the biodegradable material through the male mold and the female mold. Production method. 3. The biodegradation according to claim 1, wherein the step of heating the biodegradable material in the mold is a step of heating and foaming / firing the biodegradable material while continuing evacuation in the mold. Manufacturing method of a conductive container. The method for producing a biodegradable container according to any one of claims 1 to 3 , wherein the biodegradable material is a kneaded product obtained by kneading at least starch, pulp and water. The method for producing a biodegradable container according to claim 4 , wherein the biodegradable material contains a colorant.

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