JP2000202844A - Manufacture of spontaneously decomposable molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a spontaneously decomposable molding without particularly coating a surface with a decomposable plastic or the like simply in a manufacturing step while providing an effective waterproofness. SOLUTION: Starch and water are mixed at a ratio of, for example, 2:1 by weight, and agitated to form a paste-like starch solution 1. An inner mold 3 for molding and heated to about 90 deg.C is dipped in the solution 1. After a predetermined time is elapsed, the mold 3 is taken out, and a water-containing starch film 5 is stuck to its surface in a thickness of about 5 to 6 mm. Then, vegetable fibers 7 are adhered to the starch adhering to the surface of the mold 3. The mold 3 adhering to the film 5 and the fibers 7 is inserted into an outer mold 9 for molding, and the solution 1 is poured in a gap between the molds 3 and 9. The molds 3 and 9 are heated to a higher temperature than a heating temperature of the mold 3 to transpirate its moisture from the solution existing between the molds 3 and 9 and to solidify and mold the starch. Eventually, the molds 3, 9 are removed, and a bucket-like container 11 of the molding is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a naturally degradable molded article such as a container for disposing of garbage.

[0002]

2. Description of the Related Art Many disposable containers, packaging materials, and packaging materials currently used are formed from materials that do not degrade naturally or materials that generate harmful substances to the living body when incinerated or disposed of. It is a thing. In particular, plastics such as polyvinyl chloride are used as raw materials for containers such as shopping bags and garbage bags. Polyvinyl chloride generates substances harmful to living organisms when incinerated, and causes acid rain. Decomposition is very slow when disposed of,
Again, harmful substances are generated during the decomposition process. From the viewpoint of environmental protection, containers, packaging materials, packaging materials, and the like made of materials that do not generate harmful substances to living organisms and are naturally decomposed are required.

[0003] In addition, cereal straw and rice hulls, which are agricultural by-products, are partially reused as compost and the like, but most of them are disposed of. From the viewpoint of economic efficiency, effective utilization of these organic by-products having natural degradability is required.

As a method for producing a naturally decomposable container utilizing these organic by-products, Japanese Patent Application Laid-Open No.
There is one disclosed in -205120. The manufacturing method first mixes plant fiber such as cut straw that has been subjected to a treatment such as sterilization, water addition, and heated starch to form a starch.
After injecting this into a heated die and performing pressure molding,
Heated degradable plastic is applied to the outer surface of the molding.

[0005]

However, in such a naturally decomposable molded article produced by such a conventional production method, a basic raw material in which starch and plant fibers such as straw are uniformly mixed in advance is used. Since the main body is manufactured by heating, pressing, and molding, there are many fine gaps in the tissue, and the liquid component penetrates and leaks. Therefore, application of a plastic film is essential. In order to apply the decomposable plastic film to the outer surface, a dedicated device and appropriate temperature control are required, which is troublesome. In addition, there are various types of degradable plastic films, but an appropriate attachment method must be used for the selected one, and process control is not easy.

[0006] The surface of the degradable plastic may be subjected to a printing process to beautify its appearance.
Ordinary inks contain substances harmful to living organisms, and thus are disposed of and become polluting, and composting this container has an adverse effect on cultivation.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to apply a decomposable plastic or the like particularly to a surface thereof while providing a reliable waterproof property, a simple manufacturing process, and the like. It is an object of the present invention to provide a method for producing a naturally decomposable molded article without any problem.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and comprises immersing an inner mold for molding in a starch solution made of starch and water. Is heated, the inner mold for molding is pulled up, plant fibers are adhered to the jelly-like film adhered to the surface thereof, and the inner mold for molding with the plant fibers attached is inserted into the outer mold for molding. The gap between the inner mold and the outer mold was filled with the starch solution, and the molding inner mold and the outer mold were heated at a temperature higher than the heating temperature of the inner mold to evaporate water from the starch solution, thereby solidifying and molding. Thereafter, the molded body is removed by removing the inner mold from the outer mold for molding.

The molded article produced according to the present invention is composed of starch and vegetable fiber and therefore has a natural degradability. Further, since the inner and outer layers are dense layers composed of only starch containing no vegetable fiber, A molded article having waterproofness can be manufactured.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart showing the steps of the present invention.

First, starch and water are mixed and stirred at a weight ratio of, for example, 2: 1 to prepare a starchy starch solution 1. Then, a frusto-conical inner mold 3 heated to about 90 ° C. is immersed in the starch solution 1 (FIG. 1A), and after a certain period of time, the inner mold 3 is taken out. 5 on the surface
Jelly-like membrane 5 made of hydrated starch with a thickness of about 6 mm
To adhere. The inner mold 3 for molding has a shape of a desired final product (plate, dish-like container, bucket-like container, packing material, etc.).
Various shapes can be adopted according to the above.

Next, plant fibers 7 such as strawberries (cut straw) are sprayed or dusted on the hydrated starch attached to the surface of the inner mold for molding 3 taken out of the starch solution 1 and adhered thereto (FIG. 1 (b)). ). This plant fiber 7 is made of 5 c
It has been previously cut or crushed into a length of about m and dried.

Then, the inner mold 3 for molding having the hydrated starch membrane 5 and the plant fiber 7 attached thereto is inserted into the outer mold 9 for molding, and the above-mentioned starch solution 1 is inserted into the gap between the inner mold 3 and the outer mold 9. An equivalent or similar starch solution is injected (FIG. 1 (c)). The inside of the molding outer mold 9 has a shape similar to the outside of the molding inner mold 3, so that the finally completed product has a shape having a substantially constant thickness. Can be different from the outer shape of the inner mold 3 for molding.

Next, the inner mold for molding 3 and the outer mold for molding 9
Is heated at a temperature (for example, about 180 ° C.) higher than the heating temperature of the inner mold for molding 3 to evaporate water from a starch solution existing between the inner mold 3 and the outer mold 9 to solidify the hydrated starch. Molding (FIG. 1D). Finally, the inner mold for molding 3 and the outer mold for molding 9 are removed, and the bucket-shaped container 11 as a molded body is removed.

When the lid 13 of the container as shown in FIG. 2 is formed by the same process, the container 11 can be used as a bucket for garbage at home, for example. A plurality of stoppers 15 are provided inside the upper portion of the container 11.
Are formed at equal intervals, and projections 17 to be locked to the stoppers 15 are formed on the outer peripheral edge of the lid 13 by the same number and at the same intervals as the stoppers 15. The stopper 15 includes, for example, a vertical introduction portion 15a and a locking portion 15b that extends horizontally from the lower end of the introduction portion 15a in one direction (for example, clockwise). 1
5a, the lid 13 is rotated clockwise when it reaches the lower end, and positioned at the locking portion 15b. Also, the lid 13
It is preferable to form a finger hole 13a serving as a handle for opening and closing by rotating it.

The inner layer and the outer layer of the container 11 are dense layers in which only starch is solidified, do not leak water, and store raw garbage containing a large amount of water until the garbage is collected. Can be. Further, since the container 11 has a natural decomposability, garbage can be discarded together with the container 11. Alternatively, the garbage can be brought into the composting facility together with the container 11 and put into the composting facility.

At present, when the reduction and recycling of garbage are required, composting of garbage is one of the effective means. As in the past, if garbage was put into a plastic bag and disposed of, the bag would break down the crusher in the composting equipment, so these were manually removed. This work was not easy due to the large number of parcels and parcels, and it was virtually impossible to remove 100%.

On the other hand, according to the garbage container 11 according to the embodiment of the present invention, the labor and cost for these operations and the repair cost of the crusher can be reduced, and excellent quality can be achieved. Compost can be obtained.

[0019]

According to the present invention, a plant fiber such as rice straw, which is required to be effectively used as a resource, is used as a molding material, the production process is simple, and the natural degradable material having reliable waterproofness is provided. Can be obtained. The molded article according to the present invention can be widely used as containers and packing materials in various fields such as food, agricultural and horticulture, and transportation. Moreover, since the obtained molded body has a natural degradability, even if it is landfilled after use, it does not cause pollution.

[Brief description of the drawings]

1A is a view showing a first step of a method for producing a naturally decomposable molded article according to the present invention, FIG. 1B is a view showing a second step, and FIG. FIG. 4D is a diagram illustrating a process, and FIG. 6D is a diagram illustrating the fourth process.

FIG. 2 is a perspective view showing a molded product as a final product.

[Explanation of symbols]

 Reference Signs List 1 starch solution 3 inner mold for molding 5 water-containing starch membrane 7 vegetable fiber 9 outer mold for molding 11 container 13 lid (13a finger hole) 15 stopper (15a introduction part, 15b locking part) 17 protrusion

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 22:00 F term (Reference) 4F202 AA01 AB25 AC05 AD06 AE10 AG07 AH55 CA03 CA05 CB01 CN01 4F205 AA01 AB25 AC05 AD06 AE10 AG07 AH55 GA08 GA15 GB01 GC01 GE02 GE06 GF01 GF05 GF23 GF51 GN13 GN22 GN28 GN29 4J002 AB04W AH00X FA04X GG01

Claims (1)

[Claims] 1. An inner mold for molding is immersed in a starch solution made of starch and water, and the inner mold is heated, and the inner mold for mold is pulled up to form a jelly-like film adhered to the surface thereof. The plant fiber is adhered, the molding inner mold to which the plant fiber is adhered is inserted into the molding outer mold, the gap between the molding inner mold and the outer mold is filled with the starch solution, and the molding inner mold and the outer mold are filled. After the mold is heated at a temperature higher than the heating temperature of the inner mold to solidify and mold by evaporating water from the starch solution, the inner mold is removed from the outer mold for molding and the molded body is removed. A method for producing a naturally degradable molded article.