JP2012086406A - Method of manufacturing biodegradable container, and biodegradable container manufactured by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a biodegradable container, capable of foaming and baking a biodegradable material in a short time while preventing half-baking of an opening edge.SOLUTION: The method of manufacturing a biodegradable container comprises a step of molding a container-shaped foam base material layer by use of a foam molding mold 6 composed of a pair of mutually fittable male die 4 and female die 5, each of the dies containing a heater and being electrically connected to a high frequency oscillator, by mutually fitting the male die 4 and the female die 5 with a biodegradable material containing water interposed therebetween, and baking the biodegradable material while steam-foaming the biodegradable material by heating from the heaters and induction heating by application of high-frequency wave and diffusing steam to the outside through a portion corresponding to the opening edge. The mold 6 is formed to have a dimension such that the thickness of an opening edge 1a is smaller than the thicknesses of a bottom portion and a body portion. The step of molding the container-shaped foam base material layer by steam-foaming the biodegradable material includes a step of collectively applying the high-frequency wave to the thin opening edge 1a to collectively heat the opening edge.

Description

  The present invention relates to a method for producing a biodegradable container and a biodegradable container produced by the method, and more specifically, a method for efficiently foaming a biodegradable material containing moisture in a mold and the method The present invention relates to a biodegradable container manufactured by the method.

  As a prior art related to the present invention, a dough-like biodegradable material obtained by kneading starch, pulp and water is put into a mold heated to a predetermined temperature, and a high frequency is applied to the put biodegradable material. A method is known in which a container-like foamed molded product is formed by applying and dielectric heating, foaming and steaming in a mold and firing (see, for example, Patent Document 1).

Japanese Patent No. 3961421

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 described in Patent Document 1, as a method for producing a biodegradable container using biomass as a raw material, a dough-like biodegradable material obtained by kneading starch, pulp and water was heated to a predetermined temperature. There is known a method in which a biodegradable material is placed in a mold, dielectrically heated in the mold, and steam-foamed and fired.
According to such a method, since the biodegradable material itself generates heat by dielectric heating in addition to the heating from the mold, the biodegradable material can be rapidly foamed and fired. However, in order to improve the productivity of the biodegradable container, there is a demand for further shortening of the time required for foaming and baking of the biodegradable material.

  In general, molds used for foaming and firing of biodegradable materials are designed to release steam at the location corresponding to the opening edge of the biodegradable container in order to release water vapor generated during foaming and firing to the outside of the mold. Holes are formed.

  That is, moisture contained in the biodegradable material is released to the outside through a location corresponding to the opening edge of the biodegradable container. For this reason, the biodegradable container in the course of baking contains a large amount of moisture at the opening edge until the end, and when trying to bake in a shorter time, the moisture at the opening edge is not completely removed, and a raw burn is likely to occur.

  In order to prevent such burning of the edge of the opening, a method of increasing the output of the high frequency applied at the time of dielectric heating can be considered. However, if high-frequency, high-frequency power continues to be applied even though the bottom and body other than the opening edge have been fired, scorching is likely to occur on the previously fired bottom and body. In some cases, sparks are generated between the mold and the biodegradable material that is the object to be heated, or in the part where the object to be heated is not present in the mold, and high-frequency application itself cannot be continued.

  For this reason, the burning of the opening edge cannot be prevented by simply increasing the output of the high frequency applied. In addition, there is a method of reducing the output of the high frequency applied to the extent that no scorching or sparking occurs when the bottom part or the body part has been baked, but then it becomes impossible to fire in a short time which is the original purpose. .

  The present invention has been made in view of the above circumstances, and is capable of producing a biodegradable container that can foam and fire a biodegradable material in a shorter time while preventing the burnt edge of the opening. A method is provided.

  The present invention relates to a method for manufacturing a biodegradable container having a bottom, a body, and an opening edge, and includes a pair of male and female molds that can be fitted and are electrically connected to a high-frequency oscillator. Using a mold for foam molding, a biodegradable material containing moisture is interposed, a male mold and a female mold are fitted, and the biodegradable material is steamed by heating from a heater and dielectric heating by applying high frequency. The mold includes a step of forming a container-like foamed base material layer by firing while dissipating water vapor from the portion corresponding to the opening edge to the outside, and the mold has a thickness of the bottom edge and the body of the opening edge. In the process of forming a container-like foam base material layer by steam-foaming a biodegradable material, high frequency is applied to the opening edge with a small thickness. Including intensively heating the opening edge. There is provided a method for manufacturing the first biodegradable containers and symptoms.

  The present invention also relates to a method for manufacturing a biodegradable container having a bottom portion, a body portion, and an opening edge, and includes a pair of matable male and female members that have a built-in heater and are electrically connected to a high-frequency oscillator. Using a mold for foam molding, a biodegradable material containing moisture is interposed between a male mold and a female mold, and the biodegradable material is heated by a heater and dielectrically heated by applying high frequency. And forming the container-like foam base material layer by firing while steam is diffused to the outside from the location corresponding to the opening edge by steam foaming, the mold corresponds to the opening edge of the biodegradable container The local heating heater that intensively heats the edge of the opening is built in the part to be formed, and the step of forming the container-shaped foam base layer by steam-foaming the biodegradable material is performed from the local heating heater. The process of intensively heating the opening edge by heating Also provides a second method of manufacturing a biodegradable container characterized by Mukoto.

  Furthermore, the present invention is a method of manufacturing a biodegradable container having a bottom, a body, and an opening edge, and includes a pair of matable male and female that have a built-in heater and are electrically connected to a high-frequency oscillator. Using a mold for foam molding, a biodegradable material containing moisture is interposed between a male mold and a female mold, and the biodegradable material is heated by a heater and dielectrically heated by applying high frequency. And forming the container-like foam base material layer by firing while steam is diffused to the outside from the location corresponding to the opening edge by steam foaming, the mold corresponds to the opening edge of the biodegradable container The step of forming the container-shaped foam base layer by steam-foaming the biodegradable material is formed of a material having higher thermal conductivity than the portion corresponding to the bottom portion and the body portion. Opening edge due to the part made of high quality material Also provides a method for producing a third biodegradable container characterized in that it comprises the step of heating intensively.

  According to the first method for producing a biodegradable container of the present invention, since the mold formed so that the thickness of the opening edge is thinner than the thickness of the bottom and the trunk is used, When applying high frequency to the biodegradable material inside and heating dielectrically, high frequency is concentrated and applied to the opening edge with a small thickness and short insulation distance, and the opening edge can be heated intensively. .

  Further, according to the second method for producing a biodegradable container of the present invention, since a mold incorporating a local heating heater for locally heating the opening edge is used, the biodegradable material in the mold is used. The opening edge portion can be heated intensively when heating.

  Furthermore, according to the third method for producing a biodegradable container of the present invention, the part corresponding to the opening edge of the biodegradable container is formed of a material having higher thermal conductivity than the parts corresponding to the bottom part and the body part. Since the molded mold is used, the opening edge can be heated intensively when the biodegradable material in the mold is heated.

  That is, according to the first, second, and third biodegradable container manufacturing methods according to the present invention, the opening edge is concentrated when the biodegradable material is steam-foamed and fired in the mold. It is possible to quickly heat, and moisture contained in the opening edge can be quickly vaporized to promote firing. For this reason, firing of the opening edge portion containing a relatively large amount of water, the bottom portion, and the body portion is completed at substantially the same timing until the end of firing, and the biodegradable material is prevented while preventing burning of the opening edge portion. The time required for foaming and firing can be shortened.

It is sectional drawing of the biodegradable container manufactured by the manufacturing method which concerns on Embodiment 1 of this invention. It is the A section enlarged view of FIG. It is the B section enlarged view of 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 an electric circuit diagram of the high frequency dielectric heating apparatus used with the manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention. It is a graph which shows the control characteristic of the impedance matching circuit shown by FIG. It is a perspective view which shows the modification of the metal mold | die used with the manufacturing method of the biodegradable container which concerns on Embodiment 1 of this invention. It is CC sectional view taken on the line of FIG. It is sectional drawing of the metal mold | die used with the manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention. It is a top view of the male type | mold shown by FIG. It is a top view of the female type | mold shown by FIG. It is sectional drawing which shows the modification of the metal mold | die used with the manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention. It is a top view of the female type | mold shown by FIG. It is sectional drawing which shows the modification of the metal mold | die used with the manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention. It is a top view of the female type | mold shown by FIG. It is sectional drawing of the metal mold | die used with the manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the modification of the metal mold | die used with the manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention. It is a graph which shows the control characteristic of the conventional impedance matching circuit.

  A first biodegradable container manufacturing method according to the present invention is a method for manufacturing a biodegradable container having a bottom part, a body part, and an opening edge part, and is a fitting that incorporates a heater and is electrically connected to a high-frequency oscillator. Using a mold for foam molding consisting of a pair of male and female molds that can be mated, with a biodegradable material containing moisture interposing the male and female molds, heating from the heater and high frequency The mold has a step of foaming the biodegradable material by dielectric heating by application and forming the container-like foamed base material layer by baking while dissipating the water vapor from the portion corresponding to the opening edge to the outside. The step of forming the container-shaped foam base layer by steam-foaming the biodegradable material is formed so that the thickness of the edge portion is smaller than the thickness of the bottom portion and the trunk portion, Concentrate and apply high frequency to the thin opening edge Characterized in that it comprises the step of heating intensively.

  A second biodegradable container manufacturing method according to the present invention is a method for manufacturing a biodegradable container having a bottom part, a body part, and an opening edge part, and has a built-in heater and is electrically connected to a high-frequency oscillator. Using a mold for foam molding consisting of a pair of male and female molds that can be fitted, the biodegradable material containing moisture is interposed, the male mold and female mold are fitted, and heating from the heater is performed. A step of forming a container-like foamed base material layer by baking the biodegradable material by steam heating by dielectric heating by applying a high frequency and dissipating water vapor from the portion corresponding to the opening edge to the outside, Has a built-in local heater that heats the opening edge in a portion corresponding to the opening edge of the biodegradable container, and steam-foams the biodegradable material to form a container-like foam base material layer. The molding step is performed by heating from a local heater. Characterized in that it comprises a step of heating the opening edge portion in a concentrated manner.

  Furthermore, a third method for manufacturing a biodegradable container according to the present invention is a method for manufacturing a biodegradable container having a bottom portion, a body portion, and an opening edge, and is electrically connected to a high-frequency oscillator incorporating a heater. Using a mold for foam molding consisting of a pair of male and female molds that can be fitted, the biodegradable material containing moisture is interposed, the male mold and female mold are fitted, and heating from the heater is performed. A step of forming a container-like foamed base material layer by baking the biodegradable material by steam heating by dielectric heating by applying a high frequency and dissipating water vapor from the portion corresponding to the opening edge to the outside, The part corresponding to the opening edge of the biodegradable container is formed of a material having higher thermal conductivity than the part corresponding to the bottom and the trunk, and the biodegradable material is steam-foamed to form a container-like foam base. The step of forming the material layer is a material having high thermal conductivity. The formed said portion, characterized in that it comprises the step of heating intensively the opening edge portion.

In the first, second, and third biodegradable container manufacturing methods according to the present invention, the foam molding mold includes a pair of male and female molds that can be fitted, and a biodegradable material is used. It means a mold configured so that gas or water vapor generated when heated and foamed can be appropriately discharged from the cavity to the outside.
In the first, second, and third biodegradable container manufacturing methods according to the present invention, the biodegradable material is a material for the foamed base material layer that forms the skeleton of the biodegradable container and contains moisture. Means the one prepared in

In the first, second, and third biodegradable container manufacturing methods according to the present invention, the opening edge portion is a portion that occupies the opening of the biodegradable container and the vicinity thereof, and is formed in the mold. It means a portion where water vapor finally escapes when the decomposable material is foamed with water vapor and fired.
Further, in the first, second, and third biodegradable container manufacturing methods according to the present invention, the intensive heating of the opening edge means that the opening edge has a bottom part and a body part per unit volume in the mold. It means heating to have a larger amount of heat.

  In the first method for producing a biodegradable container according to the present invention, the mold is formed so that the thickness of the opening edge is about 60 to 90% of the average thickness of the bottom and the trunk. It is preferable to become.

This is because when the thickness of the opening edge is smaller than about 60% of the average thickness of the bottom and the body, the insulating interval of the opening edge in the mold becomes too small compared to the bottom and the body. This is because, when a high frequency is applied, the high frequency is excessively concentrated on the edge of the opening, making it difficult to dielectrically heat the entire biodegradable material.
On the other hand, when the thickness of the opening edge is larger than about 90% of the average thickness of the bottom and the body, the insulating interval of the opening edge in the mold is not much different from that of the bottom and the body, and the opening edge It becomes difficult to concentrate high frequency on the part.
Therefore, the mold is preferably formed so that the thickness of the opening edge portion is about 60 to 90% of the average value of the thickness of the bottom portion and the trunk portion.

As described above, the second biodegradable container manufacturing method according to the present invention incorporates a local heating heater in which the mold heats the opening edge in a concentrated manner.
Here, the local heater may be incorporated in at least one of the male and female dies, but in order to heat the opening edge efficiently and intensively, both the male and female dies are respectively provided. It is preferably built in.

  The configuration of the local heater is not particularly limited, for example, a configuration in which the mold can be divided and a single or a plurality of bar heaters are embedded in the vicinity of the portion corresponding to the opening edge, A structure in which the mold is separable and a single or a plurality of planar heating elements (rubber heaters) are inserted in the vicinity of the part corresponding to the opening edge, in the vicinity of the part corresponding to the opening edge in the mold The structure which forms a channel | path and circulates the heated oil to the formed channel | path, or these combined use can be mentioned.

As described above, the opening edge of the biodegradable container is a portion that becomes an outlet of water vapor when the biodegradable material is foamed and fired in the mold, and a relatively large amount of water is consumed until the end of firing. For this reason, the mold is deprived of heat when the moisture contained in the opening edge is vaporized, and the temperature is likely to decrease at a portion corresponding to the opening edge.
However, in the second method for producing a biodegradable container according to the present invention, as described above, since the mold incorporates the local heating heater that intensively heats the opening edge, it corresponds to the opening edge. The temperature drop in the portion is suppressed.
For this reason, an opening edge part can be heated efficiently and intensively, the water | moisture content contained in an opening edge part can be vaporized quickly, and baking can be accelerated | stimulated.

According to the third method for producing a biodegradable container according to the present invention, as described above, the part of the mold corresponding to the opening edge is formed of a material having higher thermal conductivity than the part corresponding to the bottom part and the body part. The
Here, the structure corresponding to the opening edge portion is formed of a material having high thermal conductivity, but is not particularly limited. For example, the portion corresponding to the opening edge portion is copper having excellent thermal conductivity. It is made of brass or brass, and the part corresponding to the bottom and the body is made of aluminum, or the entire mold is made of aluminum, and only the surface of the part corresponding to the opening edge is made of other materials having excellent thermal conductivity. The structure plated with metal, for example gold | metal | money, etc. can be mentioned.

According to these configurations, since the thermal conductivity is increased in the portion corresponding to the opening edge portion of the mold, even if the temperature corresponding to the opening edge portion is lowered due to the above-described reason, from the adjacent portion. Heat is quickly transmitted and temperature drop is suppressed at the portion corresponding to the opening edge.
For this reason, similarly to the above-described method for producing the second biodegradable container, the opening edge can be heated efficiently and intensively, and moisture contained in the opening edge can be quickly vaporized to promote firing.

The first, second and third biodegradable container manufacturing methods according to the present invention are preferably used in combination for foaming and firing the biodegradable material in a shorter time.
That is, in order to foam and fire the biodegradable material in a shorter time, the first and second biodegradable container manufacturing methods according to the present invention may be used in combination. The manufacturing method of the third biodegradable container may be used in combination. Or the manufacturing method of the 2nd and 3rd biodegradable container by this invention may be used in combination, and the manufacturing method of the 1st, 2nd and 3rd biodegradable container by this invention is combined. The combination of the manufacturing method of the 1st, 2nd and 3rd biodegradable container can be selected arbitrarily.

  For example, when the first, second, and third biodegradable container manufacturing methods according to the present invention are used in combination, an opening edge that is specifically a feature of the first biodegradable container manufacturing method A local heater, which is a feature of the second biodegradable container, is incorporated in a mold formed so that the thickness of the mold is smaller than the thickness of the bottom portion and the trunk portion. The structure which improves the heat conductivity of the part corresponding to the opening edge part which is the characteristic of a conductive container will be applied in combination. When such a mold is used, the opening edge can be heated very efficiently and intensively, and foaming / firing can be performed in a shorter time.

In the first, second and third biodegradable container manufacturing methods according to the present invention, the mold has a undulation having a predetermined height difference on the surface of a part corresponding to the body part of the biodegradable container. It may be formed repeatedly along the circumferential direction.
According to such a configuration, the flow direction of the biodegradable material is determined in the mold, and the biodegradable material quickly foams from the bottom of the biodegradable container toward the opening edge during heating.
Thereby, the time required for foaming and baking of the biodegradable material can be further shortened.

  Further, in the first, second and third biodegradable container manufacturing methods according to the present invention, the step of forming the container-like foamed base material layer by steam-foaming the biodegradable material starts the application of high frequency. Immediately after this, a step of applying a high frequency so that the output current from the high frequency oscillator reaches a predetermined peak value, maintaining the peak value for a predetermined time, and immediately stopping the application of the high frequency may be included.

  According to such a configuration, the time required for applying the high frequency is significantly shortened as compared with the conventional case, and as a result, the time required for foaming / firing of the biodegradable material can be greatly shortened.

  In other words, in the past, when applying a high frequency to dielectrically heat an object to be heated, the output from the high frequency oscillator is gradually increased after the start of application, and after the output reaches a predetermined peak value, the output is gradually decreased. The technique of finishing the application has been taken. When a high frequency is applied by such a method, the graph of the output current value draws a gentle mountain shape.

The above-described method has been adopted for the following reason.
(1) Immediately after the start of application, if the output from the high-frequency oscillator is increased all at once, it falls into an uncontrollable state and spark is generated.
(2) Even if the output reaches a predetermined peak value and the moisture contained in the object to be heated is reduced, the reflected wave becomes high when trying to maintain the peak value, which leads to scorching and sparking of the object to be heated. .
(3) It is substantially difficult to suppress the reflected wave to a level at which there is no problem from the start of application to the end of application without changing the output.

Here, immediately after the start of application, the output of the high frequency oscillator is increased to a predetermined peak value at once, and after maintaining the peak value for a predetermined time, the application of the high frequency is stopped immediately, and a graph with a trapezoidal output current value is drawn. By adopting such an application method, it is conceivable to reduce the time required for applying a high frequency.
However, in order to realize an application method in which the output current value draws a trapezoidal graph, the above problems (1) to (3) must be solved.

  Therefore, the inventor of the present application devised and improved the control accuracy by individually controlling the capacitances Cp and Cs and the inductance L without fixing them in the impedance matching circuit for matching the impedance of the high frequency oscillator and the impedance of the object to be heated. In addition to the improvement, structural improvements were made so that the inductor could be operated at high speed, and the application method for drawing the trapezoidal graph as described above could be implemented.

This improvement enables the impedance matching circuit to respond to changes in the moisture content of the biodegradable material, which is the object to be heated, in small increments, resulting in scoring, sparking, and an uncontrollable state. It can be avoided.
As a result, there is an application method in which the output current value draws a trapezoidal graph in which the output current value is increased immediately to the peak value immediately after the start of application, and after the peak value is maintained for a predetermined time, the application of high frequency is stopped immediately. This has made it possible to significantly reduce the time required to apply a high frequency.

  In the first, second and third biodegradable container manufacturing methods according to the present invention, the biodegradable material preferably contains starch and pulp.

  This is because starch and pulp are plant-derived materials that are excellent in biodegradability and low in calories burned even when burned.

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 unmodified starch and the 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.

  From another viewpoint, the present invention is a biodegradable container manufactured by the above-described manufacturing method according to the present invention, wherein the opening edge portion forming the opening is formed thinner than the bottom portion and the trunk portion. It also provides a biodegradable container.

  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 in FIG. 1, and FIG. 3 is an enlarged view of part B in FIG.

As shown in FIGS. 1 to 3, the biodegradable container 1 manufactured by the manufacturing method according to Embodiment 1 of the present invention includes a foam base material layer 2 that forms the skeleton of the biodegradable container 1, and a foam base material. It consists of a hydrophobic biodegradable film 3 that covers both the inner and outer surfaces of the layer 2.
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.

As shown in FIG. 1, the biodegradable container 1 includes an opening edge 1a that forms an opening, a bottom 1b, and a body 1c that extends between the opening edge 1a and the bottom 1b. .
Here, in the present embodiment, the opening edge 1a is specifically, as shown in FIG. 3, via the bent portion 1d that bends outward from the upper end of the body 1c to the opening end 1e. It ’s all about. In FIG. 3, a portion corresponding to the opening edge 1 a is surrounded by a dashed line.

As shown in FIG. 1, in this embodiment, the thickness T1 of the opening edge 1a is about 1.7 mm, and the thicknesses T2 and T3 of the bottom 1b and the body 1c are both about 2.0 mm. The thickness T1 of 1a is configured to be thinner than the thicknesses T2 and T3 of the bottom 1b and the trunk 1c.
That is, in the present embodiment, the thickness T1 of the opening edge 1a is set to about 85% of the average value (about 2.0 mm) of the thicknesses T2 and T3 of the bottom 1b and the body 1c.
In the present embodiment, the thickness T4 of the bent portion 1d constituting the opening edge portion 1a is about 1.91 mm, and the upper end portion of the body portion 1c connected to the bent portion 1d has a thickness of about 2.0 mm to about 1 mm. It is configured to gradually become thinner to 91 mm.

  Hereinafter, a method for manufacturing the biodegradable container 1 shown in FIG. 1 will be described with reference to FIGS. 4 and 5. 4 and 5 are process diagrams illustrating a method for manufacturing a biodegradable container according to Embodiment 1. FIG.

  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. 5C) 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 are both made of aluminum and have a built-in electric heater (not shown), and both are maintained at about 130 to 160 ° C. in the following steps.

The male mold 4 and the female mold 5 have dimensions and shapes such that the opening edge 1a, the bottom 1b, and the body 1c of the biodegradable container 1 formed by the mold 6 have the above-described thicknesses T1, T2, and T3, respectively. Is formed.
Further, as shown in FIG. 5C, the male mold 4 and the female mold 5 have inductances so that the biodegradable material 7 that is a heated object supplied into the mold 6 can be dielectrically heated. And is connected to the high-frequency oscillator 10 through an impedance matching circuit 11 with variable capacitance.
Then, the water vapor generated from the biodegradable material 7 in the cavity 9 is released to the outside at the contact point between the male mold 4 and the female mold 5, that is, the position corresponding to the opening edge 1a of the biodegradable container 1. Vapor vent holes (not shown) are formed.

First, as shown in FIG. 4A, the biodegradable material 7 is disposed above the female mold 5 with the biodegradable material 7 sandwiched between two biodegradable films 3 stretched on a frame 8. .
The two biodegradable films are preliminarily coated with titanium dioxide powder on their facing surfaces so that they do not stick to each other during the manufacturing process.
The biodegradable film 3 sandwiching the biodegradable material 7 is disposed above the female mold 5 and at the same time, the surface of the biodegradable film 3 is heated by hot air of about 100 to 150 ° C. (hot air outlet temperature). It is heated and softened to a temperature of about 100 to 120 ° C. This preheating of the biodegradable film 3 is continued until the fitting between the male mold 4 and the female mold 5 is completed.

Said biodegradable material 7 used as the material of the foaming base material layer 2 (refer FIG. 2) mixes starch with the melt | dissolution of a pulp and water, Then, it heats and gelatinizes. An appropriate amount of titanium dioxide and gelatin may be mixed with the starch so as to exhibit optimum properties as a material of the biodegradable container 1. In this embodiment, the ratio (moisture value) of water in the biodegradable material 7 is about 50 to 65% by weight, and the property of the biodegradable material 7 is dough.
On the other hand, the biodegradable film 3 is obtained by biaxially stretching a biodegradable aromatic polyester resin (Biomax (registered trademark)) and forming it into a film shape, and the thickness thereof is about 25 to 75 μm.

  Next, as shown in FIG. 4B, the male mold 4 is lowered toward the female mold 5, and the biodegradable film 3 stretched on the frame body 8 is stretched by the male mold 4.

Next, as shown in FIG. 5C, when the male mold 4 is further lowered and fitted with the female mold 5, the biodegradable film 3 is completely stretched and the biodegradable material 7 is pressurized. Then, the inside of the cavity 9 formed by the male mold 4 and the female mold 5 is gradually filled.
Then, when about 8.5 seconds have passed since the male mold 4 and the female mold 5 are fitted, the biodegradation in the cavity 9 is performed from the high frequency oscillator 10 via the impedance matching circuit 11 and the male mold 4 and the female mold 5. Application of a high frequency to the material 7 is started, and the biodegradable material 7 is dielectrically heated for about 4 to 10 seconds.

At this time, impedance matching between the high frequency oscillator 10 and the biodegradable material 7 to be heated is performed by the impedance matching circuit 11 so that the output current from the high frequency oscillator 10 is constant, and high frequency is efficiently applied. The
6 is an electric circuit diagram of the impedance matching circuit 11 shown in FIG. 5, and FIG. 7 is an output current Ip when applying a high frequency to the biodegradable material 7, the capacitances of the first and second variable capacitors Cp and Cs, and the variable It is a graph which shows the change with respect to time t of the inductance L of the inductor Ls.

As shown in FIG. 6, the impedance matching circuit 11 includes a first variable capacitor Cp connected in parallel to the high-frequency oscillator 10, and an output of the high-frequency oscillator 10 via a male mold 4 and a female mold 5. 7 is provided with a series circuit of a second variable capacitor Cs to be applied to 7 and a variable inductor Ls.
Then, as shown in FIG. 7, after the output current Ip from the high frequency oscillator 10 rises linearly from the start of high frequency application to the set value Ic and maintains this set value Ic for about 4 to 15 seconds, The capacitances of the first and second variable capacitors Cp and Cs of the impedance matching circuit 11 and the inductance L of the variable inductor Ls are individually controlled so that the application of the high frequency is immediately finished.

According to such an application method, the value of the output current Ip from the high-frequency oscillator 10 is drawn in a trapezoidal graph, and a conventional graph in which the value of the output current Ip is gentle as shown in FIG. Compared with the application method, the application time can be greatly shortened.
In FIG. 7, FW indicates an incident wave, and RW indicates a reflected wave. While the incident wave FW shows a constant value from the start of application of high frequency to the end of application by the above control of the impedance matching circuit 11, the reflected wave RW is suppressed to an extremely low value, so that the high frequency is efficiently biodegradable. It can be seen that the material 7 is applied.

  By the way, in order to realize an application method in which the value of the output current Ip draws a trapezoidal graph while suppressing the reflected wave RW to a sufficiently low value, the capacitances of the first and second variable capacitors Cp and Cs, and In addition to individually controlling the inductance L of the variable inductor Ls, it is necessary to improve the response speed of the first and second variable capacitors Cp and Cs and the variable inductor Ls.

Therefore, although not shown, in the present embodiment, the motor driving speed for changing the distance between the electrodes of the first and second variable capacitors Cp and Cs and the variable inductor Ls is increased as compared with the prior art, and the electrodes are stably moved at high speed. Therefore, the structural improvement of increasing the mounting accuracy and mounting strength of the electrodes is attempted.
As a result, it is possible to perform minute control that sequentially corresponds to a change in the moisture value contained in the biodegradable material 7, and realize an application method in which the value of the output current Ip draws a trapezoidal graph, and the time required to apply a high frequency. Is greatly shortened.

The biodegradable material 7 filled in the cavity 9, that is, the foamed base material layer 2 in the course of firing, has a thickness T1 (see FIG. 1) corresponding to the opening edge 1a as described above, and the bottom 1b or It is thinner than the thicknesses T2 and T3 of the body 1c.
For this reason, the foaming base material layer 2 in the course of firing has a shorter insulation distance at a portion corresponding to the opening edge 1a, and a higher frequency is applied more concentratedly than the bottom 1b and the body 1c.
As a result, the opening edge portion 1a is heated more intensively than the bottom portion 1b and the body portion 1c, and firing is promoted, and when the firing is performed in a short time, the opening edge portion 1a that easily retains moisture is quickly fired. can do.

That is, the moisture contained in the biodegradable material 7 is vaporized by the heating received from the mold 6 and the dielectric heating due to the application of high frequency to become water vapor, and is externally supplied from a vapor vent (not shown) formed in the mold 6. Escaped to.
Here, since the steam vent is formed at a position where the male mold 4 and the female mold 5 are in contact with each other and corresponding to the opening edge 1a as described above, the moisture contained in the biodegradable material 7 is It will be surely diffused outside through the opening edge 1a.
For this reason, the opening edge 1a contains a relatively large amount of moisture until the end of firing, and is more likely to be burnt compared to the bottom 1b and the body 1c. This is likely to occur when firing is performed in a short time. When firing of the bottom portion 1b and the body portion 1c is completed, if the application of high frequency is continued, the bottom portion 1b and body portion 1c that has already been fired. Burning occurs, and in some cases sparks occur, making it difficult to continue applying high frequency.

However, according to the present embodiment, as described above, the thickness T1 of the opening edge 1a that is likely to be burnt is set to be thinner than the thicknesses T2 and T3 of the bottom 1b and the trunk 1c. High frequency is concentrated and applied to 1a, and the opening edge 1a containing a large amount of moisture can be intensively heated to promote firing.
As a result, the time required for firing the opening edge portion 1a and the time required for firing the bottom portion 1b and the body portion 1c become substantially equal, and the time required for foaming and firing the biodegradable material 7 is shortened.

  When the biodegradable material 7 itself in the cavity 9 generates heat due to the dielectric heating, the biodegradable material 7 is rapidly foamed and fired in the cavity 9 to form the container-like foamed base material layer 2. During the steam foaming and firing, the biodegradable film 3 that has received heat and pressure in the mold 6 is brought into close contact with the fine irregularities formed on the surface of the foam base material layer 2 by the anchor effect. The inner and outer surfaces of the layer 2 are each coated with a biodegradable film 3. No adhesive is required to coat the inner and outer surfaces of the foam base material layer 2 with the biodegradable film 3, and the biodegradable film 3 can be applied to the surface of the foam base material layer 2 only by an anchor effect by pressure and heating. In close contact.

  In this embodiment, the time (application delay time) from when the male mold 4 and the female mold 5 are fitted to when high-frequency application is started is about 8.5 seconds. This time is the biodegradable material 7. Depending on the degree of fluidity, it can be appropriately selected within a range of about 10 seconds immediately after fitting.

That is, the biodegradable material 7 supplied into the mold 6 gradually extends into the cavity 9 of the mold 6 after the male mold 4 and the female mold 5 are fitted together, or close to it. It becomes a state.
For this reason, when a certain application delay time is set, the application of high frequency can be started when the biodegradable material 7 is fully filled in or close to the cavity 9, and impedance matching can be easily achieved at the time of high frequency application. Thus, the firing state is stabilized, and the elongation and foaming state of the biodegradable material 7 in the cavity 9 can be easily controlled.

However, if the application delay time is set longer, the time required for foaming / firing of the biodegradable material 7 becomes longer. Therefore, from the viewpoint of shortening the time required for foaming / firing of the biodegradable material 7, the application delay is increased. The time should be as short as possible.
Therefore, the application delay time may be appropriately set in consideration of the elongation and foaming state of the biodegradable material 7 in the cavity 9, and the biodegradable material in the cavity 9 can be set appropriately by setting the application delay time. It is possible to arbitrarily select the elongation and foaming state of 7.

  Finally, as shown in FIG. 5 (d), the mold 6 is opened, and the foamed base material layer 2 whose inner and outer surfaces are covered with the biodegradable film 3 is taken out together with the frame 8, and the excess When the biodegradable film 3 is cut, the biodegradable container 1 shown in FIG. 1 is obtained.

  As described above in detail, according to the present embodiment, the opening edge 1a is concentrated by applying a high frequency to the opening edge 1a containing a relatively large amount of moisture until the end of baking. Since the firing can be promoted by heating, the time required for firing the bottom 1b and the body 1c and the time required for firing the opening edge 1a can be made substantially equal, and the entire foam base material layer 2 is good in a short time. Can be fired.

  In the present embodiment, the thickness T1 of the opening edge 1a is set to about 85% of the average value of the thicknesses T2 and T3 of the bottom 1b and the body 1c, but the thickness T1 of the opening edge 1a is set to the bottom 1b and the body 1c. The opening 1a can be appropriately set within a range of about 60 to 90% of the average value of the thicknesses T2 and T3 of the portion 1c, and within this range, the high frequency is appropriately concentrated on the opening edge 1a. Can be promoted.

Modified Example of First Embodiment A modified example of the mold used in the method for manufacturing a biodegradable container according to the first embodiment will be described with reference to FIGS. FIG. 8 is a perspective view of a mold according to a modified example, and FIG. 9 is a cross-sectional view of the mold shown in FIG.

  As shown in FIGS. 8 and 9, the mold 16 according to the modification of the first embodiment includes an aluminum male mold 14 and a female mold 15 each including an electric heater (not shown). Similarly to the above-described mold 6, the mold 16 according to the modified example is a contact portion between the male mold 14 and the female mold 15 and corresponds to the opening edge 1 a (see FIG. 1) of the biodegradable container 1. A steam vent (not shown) is formed at the location.

Of the male mold 14 and the female mold 15, undulations 14 a and 15 a having a height difference of about 0.1 to 0.3 mm are formed on the surface of the portion corresponding to the body portion 1 c (see FIG. 1) of the biodegradable container 1. It is formed repeatedly along the circumferential direction of the portion.
And each unevenness | corrugation which forms the undulations 14a and 15a is formed so that it may extend toward the part corresponding to the opening edge part 1a from the part corresponding to the bottom part 1b of the biodegradable container 1. FIG.

Thereby, the flow direction of the biodegradable material 7 in the mold 16 is determined, and the biodegradable material 7 quickly foams from the bottom 1b toward the opening edge 1a during dielectric heating.
Note that the undulations 14a and 15a shown in FIGS. 8 and 9 are drawn with emphasis on the height difference for ease of explanation, and actually have a fineness of about 0.1 to 0.3 mm as described above. The difference in height is hardly confirmed by visual inspection. If a large height difference is provided, a portion having a short insulation interval is partially created in the cavity, and high frequency is concentrated and applied to the portion, which may prevent uniform firing. A slight elevation difference of about ~ 0.3 mm is appropriate.

  According to the mold 16 according to the modified example, biodegradability is achieved by the action of the undulations 14a and 15a formed on the male mold 14 and the female mold 15, respectively, in addition to the action of high frequency being concentrated and applied to the opening edge 1a. The material 7 can be rapidly foamed in a predetermined direction, and the entire foam base material layer 2 can be fired satisfactorily in a shorter time.

Embodiment 2
The manufacturing method of the biodegradable container which concerns on Embodiment 2 of this invention is demonstrated based on FIGS. 10 is a cross-sectional view of a mold used in the method for producing a biodegradable container according to Embodiment 2, FIG. 11 is a plan view of the male mold shown in FIG. 10, and FIG. 12 is a plane of the female mold shown in FIG. FIG.

In the method for manufacturing a biodegradable container according to the second embodiment, a mold 26 shown in FIG. 10 is used.
The mold 26 shown in FIG. 10 also has an aluminum male mold 24 incorporating an electric heater (not shown) in the same manner as the mold 6 used in the method for manufacturing the biodegradable container according to the first embodiment. A steam release hole (not shown) is formed at a location corresponding to the opening edge 1a (see FIG. 1) of the biodegradable container 1 that is a contact portion between the male die 24 and the female die 25. Is formed.

However, in this embodiment, the male mold 24 and the female mold 25 constituting the mold 26 are the thicknesses T1, T2, and T3 of the opening edge portion 1a, the bottom portion 1b, and the trunk portion 1c of the biodegradable container 1 (see FIG. 1). Are respectively formed in the same size and shape so as to be about 2.0 mm.
For this reason, in this embodiment, when high frequency is applied and the biodegradable material 7 is dielectrically heated, high frequency is intensively applied to the opening edge 1a of the biodegradable container 1 as in the first embodiment. The effect to make is not obtained.
However, as shown in FIGS. 10 to 12, the male mold 24 and the female mold 25 constituting the mold 26 of the present embodiment are locally provided for intensively heating the opening edge 1 a of the biodegradable container 1. Heating heaters 27 and 29 are provided, respectively.

Specifically, as shown in FIGS. 10 and 11, the local heating heater 27 of the male mold 24 is composed of a plurality of rod-shaped electric heaters 28, and the male mold 24 corresponds to the opening edge 1 a of the biodegradable container 1. In order to embed a plurality of rod-shaped electric heaters 28 in the portion, the upper core 24a and the lower core 24b can be divided.
That is, the plurality of rod-shaped electric heaters 28 are embedded so as to be adjacent to each other in a space formed between the upper core 24 a and the lower core 24 b, whereby the plurality of rod-shaped electric heaters 28 are opened in the biodegradable container 1. It arranges along with the part corresponding to the edge 1a.

On the other hand, as shown in FIGS. 10 and 12, the local heater 29 of the female die 25 is a ring-shaped rubber heater in which a flat heating element that generates heat when energized is covered with rubber, and the female die 25 is biodegradable. Since the local heating heater 29 is interposed in a portion corresponding to the opening edge 1a of the conductive container 1, the upper mold 25a and the lower mold 25b can be divided.
That is, the flat ring-shaped local heating heater 29 is inserted so as to fill a space formed between the upper mold 25a and the lower mold 25b, whereby the local heating heater 29 is inserted into the biodegradable container 1. It arrange | positions in the part corresponding to the opening edge part 1a.

Thus, in this embodiment, the metal mold | die 26 which provided the heaters 27 and 29 for the local heating for heating the opening edge part 1a of the biodegradable container 1 intensively to the male type | mold 24 and the female type | mold 25, respectively is used. Therefore, when the biodegradable material 7 is baked by steam foaming, the opening edge 1a containing a relatively large amount of moisture can be intensively heated until the end of baking to promote the baking of the opening edge 1a.
For this reason, the time required for firing the bottom portion 1b and the body portion 1c and the time required for firing the opening edge portion 1a can be made substantially equal, and the entire foam base material layer 2 can be fired satisfactorily in a short time. Other configurations are the same as those in the first embodiment including application of high frequency.

First Modification of Second Embodiment A first modification of a mold used in the method for manufacturing a biodegradable container according to the second embodiment will be described with reference to FIGS. FIG. 13 is a sectional view of a mold according to the first modification, and FIG. 14 is a plan view of the female mold shown in FIG.

As shown in FIGS. 13 and 14, the mold 36 according to the first modification of the second embodiment is obtained by changing the configuration of the local heating heater of the female mold 35.
In the first modified example, the local heating heater 39 of the female die 35 is constituted by a cylindrical rubber heater. For this reason, in the first modification, the local heating heater 39 is not inserted in a portion corresponding to the opening edge 1a, but is embedded so as to surround a portion immediately below the opening edge 1a.

  Further, in order to carry out such an installation method, the female mold 35 has a three-part configuration of an upper mold 35a and a lower mold 35b and an intermediate mold 35c sandwiched between the upper mold 35a and the lower mold 35b. . Other configurations are the same as those of the second embodiment, including the configuration of the male mold 34.

Second Modification of Second Embodiment A second modification of the mold used in the method for manufacturing a biodegradable container according to the second embodiment will be described with reference to FIGS. 15 and 16. 15 is a cross-sectional view of a mold according to a second modification, and FIG. 16 is a plan view of the female mold shown in FIG.

As shown in FIGS. 15 and 16, the mold 46 according to the second modification of the third embodiment is obtained by changing the configuration of the local heating heater of the female mold 45.
In the second modification, the local heating heater 49 of the female mold 45 is constituted by an oil heater that circulates heated oil (not shown) in a passage 49a formed so as to surround a portion immediately below the opening edge 1a. Has been.

  The passage 49a is formed between the upper mold 45a and the lower mold 45b, and both ends of the passage 49a are opened to the outside of the female mold 45 to form an inlet 49b and an outlet 49c. The heated oil flows in from the inflow port 49b, heats the periphery of the passage 49a, and then is discharged from the discharge port 49c. Other configurations are the same as those of the second embodiment, including the configuration of the male mold 44.

As described above, in the present embodiment, the rod-shaped electric heater, the rubber heater, and the oil heater have been described as specific examples of the local heating heater. However, the local heating heater is not limited to these heaters, and depends on the purpose. Various heaters for local heating can be used.
Further, in the present embodiment, the combination of the rod-shaped electric heater and the rubber heater and the combination of the rod-shaped electric heater and the oil heater have been described as examples, but the combination of the local heating heaters is not limited to these, and the purpose Various combinations can be adopted depending on the situation.

Embodiment 3
The manufacturing method of the biodegradable container which concerns on Embodiment 3 of this invention is demonstrated based on FIG. 17 and FIG. FIG. 17 is a cross-sectional view of a mold used in the method for manufacturing a biodegradable container according to the third embodiment.

In the biodegradable container manufacturing method according to Embodiment 3, a mold 56 shown in FIG. 17 is used.
The mold 56 shown in FIG. 17 also has a male mold 54 and a female mold 55 that incorporate an electric heater (not shown) in the same manner as the mold 6 used in the biodegradable container manufacturing method according to the first embodiment. A steam vent (not shown) is formed at a position where the male mold 54 and the female mold 55 are in contact with each other and corresponding to the opening edge 1a (see FIG. 1) of the biodegradable container 1. The

However, the male mold 54 and the female mold 55 constituting the mold 56 in the present embodiment are the thicknesses T1, T2, and T3 of the opening edge 1a, the bottom 1b, and the trunk 1c of the biodegradable container 1 (see FIG. 1). Are respectively formed in the same size and shape so as to be about 2.0 mm.
For this reason, in this embodiment, when high frequency is applied and the biodegradable material 7 is dielectrically heated, high frequency is intensively applied to the opening edge 1a of the biodegradable container 1 as in the first embodiment. The effect to make is not obtained.
However, as shown in FIG. 17, the male mold 54 and the female mold 55 constituting the mold 56 of the present embodiment can intensively heat the opening edge 1 a of the biodegradable container 1. The portion corresponding to the opening edge portion 1a of the biodegradable container 1 is formed of a material having higher thermal conductivity than the portions corresponding to the bottom portion 1b and the trunk portion 1c.

Specifically, as shown in FIG. 17, the male mold 54 includes an upper core 54a and a lower core 54b, and an intermediate core 54c sandwiched between the upper core 54a and the lower core 54b.
The lower core 54b is a portion that is in contact with the inner peripheral surface of the bottom 1b and the body 1c of the biodegradable container 1, and is formed of aluminum, while the intermediate core 54c is an inner peripheral surface of the opening edge 1a of the biodegradable container 1. Therefore, it is made of copper having higher thermal conductivity than aluminum forming the lower core 54b.
The upper core 54a is a portion that does not come into contact with the biodegradable container 1, and is formed of aluminum similarly to the lower core 54b.

On the other hand, as shown in FIG. 17, the female mold 55 is composed of an upper mold 55a and a lower mold 55b.
The lower mold 55b is a portion that is in contact with the outer peripheral surface of the bottom portion 1b and the body portion 1c of the biodegradable container 1, and is formed of aluminum. The upper mold 55a is in contact with the outer peripheral surface of the opening edge portion 1a of the biodegradable container 1. Since it is a part, it is formed of copper having higher thermal conductivity than aluminum forming the lower mold 55b.

As described in the first embodiment, the opening edge 1a of the biodegradable container 1 is a portion that contains a relatively large amount of moisture until the end of baking, so that the mold 56 corresponds to the opening edge 1a. When the moisture contained in the opening edge 1a is vaporized, heat is lost and the temperature is likely to decrease.
However, as described above, the mold 56 used in the present embodiment has the thermal conductivity of the portion corresponding to the opening edge portion 1a of the biodegradable container 1 higher than that of the other portions. Even if heat is deprived when vaporizing contained moisture, the deprived heat is quickly compensated by heat conduction from other adjacent parts, and the temperature drop of the part corresponding to the opening edge 1a is suppressed as much as possible. Can do.

Thereby, it becomes possible to give more heat to the opening edge 1a of the biodegradable container 1, and the opening edge 1a containing a relatively large amount of moisture is intensively heated until the end of baking to open the opening edge 1a. Can be fired.
As a result, the time required for firing the bottom portion 1b and the body portion 1c and the time required for firing the opening edge portion 1a can be made substantially equal, and the entire foam base material layer 2 can be fired satisfactorily in a short time. Other configurations are the same as those in the first embodiment including application of high frequency.

Modification of Embodiment 3 A modification of the mold used in the method for manufacturing a biodegradable container according to Embodiment 3 will be described with reference to FIG. FIG. 18 is a cross-sectional view of a mold according to a modification.

As shown in FIG. 18, the mold 66 according to the modification of the third embodiment corresponds to the opening edge 1 a in order to increase the thermal conductivity of the portion corresponding to the opening edge 1 a of the biodegradable container 1. Gold plating 67, 68 excellent in thermal conductivity is applied to the surface of the portion to be processed. The male mold 64 and the female mold 65 constituting the mold 66 are made of aluminum as in the first embodiment.
As described above, the above-described embodiment is also obtained by applying the gold platings 67 and 68 having excellent thermal conductivity to the surface of the male mold 64 and the female mold 65 corresponding to the opening edge 1a of the biodegradable container 1. 3 can be produced, and the time required for foaming and firing of the biodegradable material 7 can be shortened.

  For ease of explanation, the thickness of the gold platings 67 and 68 is drawn with emphasis in FIG. 18, but the thickness (film thickness) of the gold platings 67 and 68 is about 3 to 5 μm, and the aluminum background is exposed. No step is formed at the boundary between the portion that has been subjected to gold plating 67 and 68.

As mentioned above, in this embodiment, in order to raise the heat conductivity of the part corresponding to the opening edge part 1a of the biodegradable container 1 rather than another part, the part corresponding to the opening edge part 1a is formed with a copper material or gold plating. In addition, although the configuration in which other portions are formed of aluminum has been described, the present embodiment is not limited to these, and various configurations and materials can be employed depending on the purpose.
For example, dissimilar material incorporation and plating may be used together, or various types of materials such as incorporating a dissimilar material with excellent thermal conductivity in one of the male mold and female mold and plating with excellent thermal conductivity on the other, etc. Modifications can be made.
Moreover, the combination of materials is not limited to aluminum, copper, and gold, and various combinations of materials can be employed.

  As described above in detail, according to the present invention, by intensively heating the opening edge of the biodegradable container containing a relatively large amount of moisture until the end of baking to promote baking, The time required for firing the body portion and the time required for firing the opening edge portion can be made substantially equal, and the entire foam base material layer can be fired satisfactorily in a short time.

In the present invention, as a method of intensively heating the opening edge, a method of intensively applying a high frequency to the opening edge using a mold formed so as to reduce the thickness of the opening edge, A method of providing a local heater for heating the portion intensively in the mold and a method of forming a portion corresponding to the opening edge portion of the mold with a material having high thermal conductivity have been described.
However, these methods may be used in combination. Rather, it is preferable to use them in combination for foaming and baking the biodegradable material in a shorter time.

  That is, in order to foam and fire the biodegradable material in a shorter time, the biodegradable container manufacturing method according to Embodiments 1 and 2 of the present invention may be used in combination, or an embodiment of the present invention. The methods for producing biodegradable containers according to 1 and 3 may be used in combination. Or the manufacturing method of the biodegradable container which concerns on Embodiment 2 and 3 of this invention may be used in combination, and the manufacturing method of the biodegradable container which concerns on Embodiment 1, 2, and 3 of this invention is combined. The combination of the biodegradable container manufacturing methods according to Embodiments 1, 2, and 3 can be arbitrarily selected.

  For example, when the manufacturing method of the biodegradable container according to Embodiments 1, 2, and 3 of the present invention is used in combination, specifically, an opening that is a feature of the manufacturing method of the biodegradable container according to Embodiment 1 A local heating heater, which is a feature of the biodegradable container according to the second embodiment, is incorporated in a mold formed so that the thickness of the edge portion is smaller than the thickness of the bottom portion and the trunk portion, and further implemented. The structure which improves the heat conductivity of the part corresponding to the opening edge part which is the characteristic of the biodegradable container which concerns on form 3 will be applied combining. When such a mold is used, the opening edge can be heated very efficiently and intensively, and foaming / firing can be performed in a shorter time.

DESCRIPTION OF SYMBOLS 1 Biodegradable container 1a Opening edge part 1b Bottom part 1c Trunk part 1d Bending part 1e Opening edge part 2 Foaming base material layer 3 Biodegradable film 4, 14, 24, 34, 44, 54, 64 Male type | mold 5, 15, 25, 35, 45, 55, 65 Female mold 6, 16, 26, 36, 46, 56, 66 Mold 7 Biodegradable material 8 Frame body 9 Cavity 10 High frequency oscillator 11 Impedance matching circuit 14a, 15a Concavity 24a, 54a Upper cores 24b, 54b Lower cores 25a, 35a, 55a Upper molds 25b, 35b, 55b Lower molds 27, 29, 39, 49 Local heater 28 Bar-shaped electric heater 35c Intermediate mold 49a Passage 49b Inlet 49c Outlet 54c Intermediate core 67, 68 Gold-plated Cp First variable capacitor Cs Second variable capacitor Ls Variable inductor

Claims (8)

  A method for manufacturing a biodegradable container having a bottom part, a body part, and an opening edge part, for foam molding comprising a pair of male and female molds that can be fitted and have a built-in heater and electrically connected to a high-frequency oscillator Using a metal mold, the biodegradable material containing water is interposed, the male and female molds are fitted, and the biodegradable material is steam-foamed by heating from the heater and dielectric heating by applying a high frequency to open the edge And a step of forming a container-shaped foamed base material layer by calcination while dissipating water vapor from the portion corresponding to the portion to the outside, and the thickness of the opening edge of the mold becomes thinner than the thickness of the bottom portion and the trunk portion The step of forming a container-shaped foamed base material layer by steam-foaming a biodegradable material is formed so as to have a size, and a high frequency is concentrated and applied to a thin opening edge. Characterized by the process of intensively heating Method for producing a disintegratable container.   The method for producing a biodegradable container according to claim 1, wherein the mold is formed so that the thickness of the opening edge is 60 to 90% of the average value of the thickness of the bottom and the body.   A method for manufacturing a biodegradable container having a bottom part, a body part, and an opening edge part, for foam molding comprising a pair of male and female molds that can be fitted and have a built-in heater and electrically connected to a high-frequency oscillator Using a metal mold, the biodegradable material containing water is interposed, the male and female molds are fitted, and the biodegradable material is steam-foamed by heating from the heater and dielectric heating by applying a high frequency to open the edge And a step of forming a container-like foamed base material layer by calcination while dissipating water vapor from the portion corresponding to the part to the outside, and the mold has an opening edge at a part corresponding to the opening edge of the biodegradable container The step of forming a container-shaped foamed base material layer by steam-foaming a biodegradable material is incorporated into the opening edge by heating from the local heating heater. Including a step of intensive heating Method of manufacturing a biodegradable container.   A method for manufacturing a biodegradable container having a bottom part, a body part, and an opening edge part, for foam molding comprising a pair of male and female molds that can be fitted and have a built-in heater and electrically connected to a high-frequency oscillator Using a metal mold, the biodegradable material containing water is interposed, the male and female molds are fitted, and the biodegradable material is steam-foamed by heating from the heater and dielectric heating by applying a high frequency to open the edge And a step of forming a container-shaped foamed base material layer by firing while dissipating water vapor from the portion corresponding to the portion to the outside, and the mold has a portion corresponding to the opening edge of the biodegradable container at the bottom and the body. The step of forming a container-shaped foam base layer by steam foaming the biodegradable material is formed of a material with high thermal conductivity. A process for intensively heating the opening edge by the above-mentioned portion. Method for producing a biodegradable container characterized in that it comprises a.   The said metal mold | die is formed repeatedly on the surface of the part corresponding to the trunk | drum of a biodegradable container so that the unevenness | corrugation which has a predetermined height difference may follow the circumferential direction of a trunk | drum. The manufacturing method of the biodegradable container as described in one.   The step of forming the container-shaped foam base layer by steam-foaming the biodegradable material applies a high frequency so that the output current from the high frequency oscillator reaches a predetermined peak value immediately after the start of the application of the high frequency, The method for producing a biodegradable container according to any one of claims 1 to 5, comprising a step of immediately stopping application of a high frequency after maintaining the peak value for a time.   The method for producing a biodegradable container according to any one of claims 1 to 6, wherein the biodegradable material contains starch and pulp.   The biodegradable container manufactured by the manufacturing method as described in any one of Claims 1-7.

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