JPH01213500A - Production of paper molded article - Google Patents

Abstract

PURPOSE:To obtain paper molded article without any drying process or any strain even in complex shaped article, capable of producing in a short time and a low cost, by mixing fragments given by beating of waste paper in a dried state with low-melting synthetic fibers, filament separating and thermoforming. CONSTITUTION:Wasted paper of Japanese paper or machine-made paper, etc., is crushed as possible as fine in a dried state. Resultant fragments are mixed with low-melting (preferably 110-200 deg.C) synthetic fibers (e.g., polyester fiber, PP fiber, PE fiber and polyamide fiber, preferably 1.5-3.0de fiber size and 3-10mm fiber length), filament separated and thermoformed to afford the aimed article.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a paper molded article.

(Prior Art) Various processing methods have been used for manufacturing paper molded products in Japan since ancient times. These are made by pasting the waste paper in its original form on top of a shaped object such as paper or wood several times using water-soluble wet adhesive such as starch paste or glue. Met.

For example, the famous ``Machi Daruma Toy'' and ``Spinning Top Dog Toy,'' which are also known as ``Paper Mache,'' can also be considered paper molded products.

There is also a local specialty product called ``-Kanbari'', which is made by coating waste paper with a water-soluble wet adhesive such as starch paste, sumac, or glue, and making shapes from the paper itself. It was a time-consuming manufacturing method that involved pasting it on a wall and exposing it to the sun to dry naturally several times each time, and it was only produced in small quantities as a craft.

In addition, as a manufacturing method for paper molded products, paper is accumulated in water to sufficiently swell the cellulose fibers that are the raw material for paper, and then the paper is beaten finely in a wet state, and then clay The "paper clay method" involves shaping, drying, and solidifying like craftsmanship.
There was also a method for manufacturing paper molded products called .

In addition, there are other products similar to the production of paper molded products.
There is a method of utilizing a valve containing solids and paper manufacturing wastewater as disclosed in Japanese Patent Application Laid-Open No. 48-7063.

This is a manufacturing method that dehydrates extremely watery materials using water-absorbing organic and inorganic substances, and then mixes water-soluble glue, synthetic resin, etc. that adheres even in wet conditions and uses it as an adhesive. there were.

(Problems to be Solved by the Invention) All conventional methods for manufacturing paper molded products involve molding using water-soluble adhesives and materials such as cellulose fibers that absorb water and swell. , had it in the product.

Therefore, water remained inside even after it was made into a paper molded product. To prevent this, drying was repeated over a long period of time.

In conventional manufacturing methods, water gradually moves to the outside of the paper molded product over time and evaporates.
As the paper molded product dried from the outside, the outer shape became distorted.

Unlike conventional methods, there was a need for a method that would allow paper moldings to be made without requiring time-consuming drying in the sun and without causing distortion.

(Means for Solving the Problems) The present invention is a paper molded product characterized by mixing a crushed product obtained by beating waste paper in a dry state and a synthetic fiber with low heat melting property, dividing the mixture, and then heat-forming it. This is a manufacturing method.

That is, water is not used during beating, the product is beaten in a dry state to form a crushed product, and the use of water-soluble adhesives for adhesion is also eliminated. The purpose of this invention is to invent and provide a method for manufacturing paper molded products using a dry method without water.

(Action of invention) The present invention will be explained in detail according to the order of steps ① to ②.

■ Beating of waste paper: The waste paper is crushed into small pieces until the original shape of the paper disappears.

The waste paper used as the raw material can be either Japanese paper or Western paper. Also, valve waste from the papermaking raw material layer may be used. A groundwood valve or a chemical valve may be used. There is no problem in mixing these.

These raw materials are crushed as finely as possible. The machine used for this beating is not particularly limited. It is fine if the waste paper is crushed into thin pieces. (This will be referred to as raw material A hereafter.) ■1 Preparation of synthetic fibers...As synthetic fibers, thermoplastic fibers such as polyester fibers, polypropylene fibers, polyethylene fibers, and polyamide fibers can be used, but especially those with low heat melting properties. Good. Melting point: 110-200
°C synthetic fibers are preferred. Preferably, the fibers have a thickness of about 1.5 to 3.0 deniers and a fiber length of about 3 to 10 mm.

(Hereinafter, this will be referred to as raw material B.) ② Mixing and fiber division: The raw materials A and B described above are mixed and fiber divided. The mixing ratio is by weight: A:B=50:50 to A:B=80:
20 is the standard.

The higher the ratio of raw material B, the harder the paper molded product will be, so the mixing ratio is adjusted depending on the strength required for the product. These two raw materials A and B are mixed and separated using a turbo mill.

Here, the mixture is stirred at a rate of 5000 times/min.

Inside this turbo mill machine, the two raw materials A and B are sufficiently mixed and separated, and then they are ejected from a slit drum rotating in the center of the turbo mill machine. (This will be referred to as a mixed raw material hereinafter.) At this time, the raw material A portion is made to have a fiber length of about 0.5 mm. The shorter the fiber length of raw material A, the smoother the surface of the paper molded product.

■Separation of air using a cyclone...inside the turbo mill machine,
Although the mixed raw material is divided into fibers, air is also trapped inside the mixed raw material at the same time, resulting in a bulky and scattered state. Since it is difficult to mold the material as it is, it is taken out from the turbo mill machine using a suction pump and introduced into a cyclone machine, where the air is separated from the mixed raw materials and released to the outside.

(2) Heat molding: The settled mixed raw materials are placed in a mold at the bottom of a cyclone machine, and molded under pressure and heat at a pressure of about 1000 kg/cm and a temperature of about 200°C. The synthetic fiber of the raw material B is thermally melted by heating and serves as a binder for bonding the cellulose fibers to the raw material, so that the entire fiber becomes thermoplastic and can be thermoformed.

In particular, when molding a fine shape, it is recommended to perform two-stage molding. That is, in the first stage, the material is put into a quasi-E shape at a temperature of 80 to 90°C and roughly formed by applying a pressure of 10 to 20 kg/ctn, and then in the second stage, the material is molded at a temperature of 200°C.
Main molding is carried out by applying pressure and heating at 1000 kg/ctn' at ℃.

In this way, the synthetic fibers of raw material B are thermally melted and serve as a binder for bonding the cellulose fibers to the raw material, thereby completing a thermoplastic paper molded product. Thereafter, the surface can be painted if desired.

It is also possible to change the strength, hardness, etc. of the paper molded product by changing the ratio of raw materials and the pressure and temperature of molding.

Examples will be described below.

(Example) Fruit "1 example" - Raw material A 70% raw material B
(Polyester fiber) After mixing 30% and separating the fibers using a turbo mill machine, air was removed using a cyclone machine, and the mixture was applied to a molding machine.

Molding was carried out at a pressure of 1000 kg/cm' and a temperature of 180° C. for 10 minutes. Raw material B was mostly melted to form a thermoplastic dish. The result was a Western-style plate with a diameter of 20 cm and a thickness of 0.5 cm. When I painted the surface and used it, I was able to create something that would not break even if dropped and looked better than a plastic product.

Seed collection 2 Raw material A 40% raw material B
(Polyethylene fiber) A floor decoration ornament was made by mixing the two raw materials (polyethylene fiber) at 60%, separating the fibers, deairing them, and performing the two-stage molding in step (2) above.

After painting and finishing it, it turned out to be elegant.

Further, there was almost no deformation after molding.

(Effects of the invention) Conventional production of paper molded products involved the inefficient work of drying in the sun, but the paper molded products of the present invention do not use any water, so the drying process can be eliminated. This makes it possible to shorten manufacturing time.

Furthermore, the paper molded article produced according to the present invention does not become distorted even if left for a long period of time. Therefore, even molded products with complex shapes can be produced in large quantities in a short time.

The paper molded product manufactured by the manufacturing method of the present invention can be used almost the same as plastic materials, and is inexpensive.

The outside can also be painted and used for various purposes.

Examples of products using the manufacturing method of the present invention include building materials such as parts of pillar corners of houses, wall and ceiling corners, wall boards, and small items such as toys, photo frames, and tableware. It is possible.

(that's all)

Claims (1)

[Claims] A method for producing a paper molded product, which comprises mixing a crushed product obtained by beating waste paper in a dry state with low heat-melting synthetic fibers, dividing the mixture into fibers, and then heat-forming the mixture.