JPH0457734A - Pollution-free vessel and its manufacturing method - Google Patents

Abstract

PURPOSE:To supply a vessel which itself is harmless and free from contamination of food and which when disposed of as waste in the environment decomposes relatively easily without causing environmental pollution by forming a molding of a moldable composition formed of mineral particulates with a specific range of particle diameter, a fibrous reinforcing material, a vegetable binder, a foaming agent, and water and by subjecting the molding to heat treatment for foaming and simultaneously for curing by drying. CONSTITUTION:A moldable composition is formed by mixing well 35 parts of sufficiently rinsed sea sand, 15 parts of pulverized waste paper, 45 parts of flour, and 5 part of sodium bicarbonate and by kneading the mixture with gradual addition of approximately 55 parts of water to obtain a composition somewhat hard. This composition is sandwiched in a bowl-shaped mold to form a molding with a thickness of approximately 1.5mm. The molded piece, without being released from the mold, is subjected to heating at 250 deg.C in a furnace, and released after heating for approximately 10 minutes. As a result, bowl-shaped heat-insulating vessel which is light in weight, has good tenacity, and has no permeability to air is obtainable. The sand used should have particle diameters of over 50mum.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a pollution-free container used for food packaging, etc.

[Conventional technology]

Conventionally, foamed polystyrene, polyolefin, vinyl resin, etc. have been widely used in food packaging, etc., and when these are discarded, they cause pollution problems because they are difficult to decompose in the environment.

When attempting to incinerate these wastes in order to deal with such pollution problems, there is a problem that the combustion heat is high and damages the incinerator. In addition, methods have been proposed to introduce structures that are easily decomposed by light or oxygen in the environment, but although it is possible to make the structure more fragile, it has not yet been possible to completely decompose and eliminate the structure.

Some attempts have been made to use materials such as wood or paper that are easily decomposed in the environment, but these have the drawbacks of slow decomposition and waste of valuable forest resources.

[Problem to be solved by the invention]

Therefore, the present invention aims to provide a non-polluting container that is itself harmless and does not contaminate the food it comes into contact with, and also relatively easily decomposes and does not cause pollution problems when discharged into the environment. This is what we are trying to provide.

[Means for Solving the Problems] A pollution-free container that can achieve the above-mentioned purpose uses a plastic composition containing mineral particles with a particle size of 50 μm or more, a fibrous reinforcing material, a vegetable binder, a blowing agent, and water. It can be produced by the method of the present invention, which is characterized in that it is molded and then heat treated to foam and dry and harden at the same time.

In the present invention, the mineral particles contained in the plastic composition that is the material for making the pollution-free container are preferably sand,
For example, fine sea sand is used, but it is necessary that the particle size is not smaller than 50 μm. If the particle size is smaller than this, foaming will not proceed uniformly during heat treatment of the plastic composition, resulting in cracking or deformation, and there will be disadvantages in that the strength of the product will decrease.

Furthermore, the fibrous reinforcing material is selected from wood bulbs, cellulose fibers such as cotton, and mineral fibers such as glass fibers and rock wool; for example, recycled bulbs obtained by dissolving waste paper are preferably used. It will be done.

The vegetable binder blended into the plastic composition is preferably a hydrated carbonaceous material such as starch, mannan, agarose, etc. Among them, wheat flour is particularly preferably used. Further, as the blowing agent used at the same time, yeast, baking powder, bicarbonate of soda, etc. are preferably used.

Further, the content ratio of each of these components in the plastic composition is preferably 25 to 45% of mineral particles, 10 to 30% of fibrous reinforcing material, and 40 to 60% of vegetable binder. By containing a sufficient amount of water, the composition needs to have appropriate hardness and plasticity so that it can maintain its shape when molded.

A plastic composition having such a composition is molded into the shape of a container using, for example, a mold, but if the self-supporting nature of the molded object is small, it can be moved to the next heat treatment step without being removed from the mold. Such heat treatment is for example 150 to 25
This is preferably carried out in an oven at about 0°C, and the heat treatment progresses foaming and drying and solidification at the same time, converting the molded product into a container with sufficient mechanical strength.

[For production]

The pollution-free containers obtained in this way are light and strong, have no air permeability, and have heat insulation properties, and can be used as is, or by coating the inner or outer surfaces with water-resistant paint, etc., for packaging various goods, especially foods. It can be used as When discarded, it is easily decomposed by microorganisms in the soil, and not only does it not cause environmental pollution (it also has an excellent soil improvement effect).

〔Example〕

35 parts of well-washed sea sand, 15 parts of finely pulverized waste paper, 45 parts of wheat flour, and 5 parts of bicarbonate of soda were thoroughly mixed, and about 55 parts of water was added little by little and kneaded to obtain a hard plastic composition.

This composition is sandwiched between bowl-shaped molds to a thickness of approximately 1.5 cm.
A molded body was formed, and the mold was placed in a furnace at 250°C for about 10 minutes without removing it. When it was removed from the mold, it turned out to be a light, non-porous, bowl-shaped insulating container. was gotten.

Also, when I filled this container with water and left it for a day and night, no deformation was observed.

〔Effect of the invention〕

According to the method for producing a pollution-free container of the present invention, a durable container with low specific gravity and high heat insulation properties can be obtained.

In addition to being useful for packaging foods, such containers can also be used as seedling pots, etc., and have the advantage that even if they are discarded, they gradually decompose and become integrated with the soil without causing environmental pollution.

Claims (4)

[Claims] (1) A plastic composition containing mineral particles with a particle size of 50 μm or more, a fibrous reinforcing material, a vegetable binder, a foaming agent, and water is molded, and then heat treated to foam and simultaneously dry and harden. A unique manufacturing method for pollution-free containers. (2) The mineral particles are sand, the fibrous reinforcement is selected from cellulose fibers such as wood pulp and cotton, and mineral fibers such as glass fiber and rock wool, and the vegetable binder is starch. The method for producing a pollution-free container according to claim 1, wherein the container is made of hydrous carbonaceous material such as mannan, agarose, or the like. (3) Mineral particles 25-45%, fibrous reinforcement 10-3
2. The method for producing a pollution-free container according to claim 1, wherein a plastic composition is used, which comprises a formulation comprising 0%, 40 to 60% of a vegetable binder, and a sufficient amount of water to obtain plasticity. (4) A pollution-free container made of a composite material containing 25-45% mineral particles with a particle size of 50 μm or more, 10-30% fibrous reinforcing material, and 40-60% vegetable binder.