JPS6030304A - Manufacture of synthetic wooden plate - Google Patents

Abstract

PURPOSE:To obtain the synthetic wooden plate excellent in property by a method in which resin and wooden powder, etc. are preheated and kneaded, and after said material has been crushed, it is supplied onto a heating plate or a frame and is formed by a heat press. CONSTITUTION:The thermoplastic synthetic resin such as polyolefine family, etc. and wooden powder are put into a preheated mixer and kneaded, thereby fusion-bonding the resin to the wooden material. After this material has been cooled at room temperature, it is crushed by using a breaker, and is charged into a frame, and then is pressurized under heating at specified pressure and temperature by a heat press. After said material has been deaerated and cooled, it is taken out from the frame. Consequently, the synthetic wooden plate excellent in uniformity and heat processing characteristics may be obtained.

Description

[Detailed description of the invention] By mixing a thermoplastic synthetic resin with wood powder, granules, or fibers and forming it into a plate, an inexpensive product that has both the properties of wood and the properties of thermoplastics can be produced. It is easy to imagine that synthetic wood boards could be obtained, and various attempts are currently being made, but for example, when using extrusion molding, molding is difficult unless the resin mixture ratio is about 50% or more. Also, the molding cost becomes extremely high, making it impossible to obtain inexpensive products. In addition, when using the press molding method, the resin cannot be used unless it is a powder, and in this case, it is a very difficult task to uniformly charge a mixture of resin powder and wood flour, etc. onto a hot plate or mold. . In other words, even if resin powder and wood powder are mixed evenly, their shape, particle size, and specific gravity are completely different, so when they are placed on a flat plate, they are separated by vibration and air resistance, resulting in a homogeneous synthetic wood board. I can't get it. The present invention has been made to solve such problems.

In the method of the present invention, the resin and wood flour are heated and kneaded in advance, so that the resin is fused to the surface of the wood flour and the wood and resin are sufficiently blended. Therefore, even if this is crushed, the wood powder etc. and the resin will not be separated again.

Also, distribute g evenly on the hot plate and formwork! Ii! There is no need for separation even if you use vibration or airflow to spread the mixture. Even after molding using a hot press, the resin and wood flour etc. remain uniformly mixed, so a high quality synthetic wood board can be obtained.

To heat and knead, for example, use a Banbury mixer and knead for 2 to 8 minutes, and the mixture of resin and wood flour will generate heat and reach a temperature of 150°C or higher.The molten resin will be mixed with wood flour, etc. The purpose can be fully achieved by fusing it to the surface of.

However, if the heat-mixing method is carried out excessively, the shape of the wood powder etc. will be destroyed, or the resin will impregnate the interior of the wood, causing the wood to lose its properties. It is necessary to stop and cool down as soon as possible.

In the crushing process, if the particle size is set to about 10 to 20 mesh, the particles can be transported and placed using air flow, which is very advantageous for streamlining production.

The pressing process takes a shorter time than the pond extrusion method, calendar roll method, etc., so the wood flour, etc. is not destroyed, and the pressing method also reduces the content of the wood flour, etc. 8
Since it is possible to increase the specific gravity to 0%, it is possible to obtain low-cost wood boards with low specific gravity. Further, as a heat press machine, either a batch type or a continuous type may be used.

The materials used in the method of the present invention will now be explained.

As the thermoplastic synthetic resin, polyolefin-based, vinyl chloride-based, polystyrene-based, polyurethane-based resins, or chemically modified polymers or copolymers thereof are used. Any shape can be used, such as granular, powder, coarse granular, etc.

The wood powder, granules, or fibers may be commercially available wood flour, coarse wood flour, crushed wood bark used for fiberboard, or wood fibers such as pulp.

It is preferable that the blending ratio of resin and wood flour is as low as possible. In the method of the present invention, the resin ratio is adjusted to 2 in order to sufficiently blend the resin and wood flour etc.
Although a perfect molded product can be obtained even if the amount is reduced to 0%, a value of about 80 to 40% is usually appropriate.

The synthetic wood board thus obtained is homogeneous and has excellent heat processability, and sufficient strength can be obtained by pasting reinforcing paper on both sides, making it useful as a wood board for processing curved surfaces. .

Next, the method of the present invention will be specifically explained using examples.

Example 1 As a thermoplastic synthetic resin, high-density polyethylene, Hyzeggs 2100J-PlQ manufactured by Mitsui Petrochemical Industries, Ltd.
and cellulosin 545 manufactured by Kajino Sangyo Co., Ltd. as wood powder.
(moisture 10%) and 70 parts of the mixture were placed in a Banbury mixer preheated to 100°C and kneaded.The temperature of the mixture started to rise rapidly in about 80 seconds, and reached 165°CK in 2 minutes. The kneading was stopped and the mixture was taken out. At this time, the polyethylene had already melted and was sufficiently mixed with the wood flour and integrated.

After cooling naturally, this was crushed to about 10 mesh using a crusher, placed in an aluminum formwork treated with fluororesin, and heated using a heat press at a pressure of 5 kQ/d and a temperature of 160°C.
Heat and pressurize for 7 minutes, deaerate, cool and remove from the mold to obtain a synthetic wood board with a thickness of 6 mm. Hyzeggs 2100J-P2O manufactured by Kogyo Co., Ltd.
and cellulosin flat 45 manufactured by Kajino Sanshiba Co., Ltd. as wood powder.
(moisture 10%) and 80 parts of the mixture are placed in a Banbury mixer preheated to 100°C and kneaded.The temperature of the mixture begins to rise rapidly in about 80 seconds, and after 2 minutes and 80 seconds the temperature reaches 165°C.
When the temperature was reached, kneading was stopped and the mixture was taken out. At this time, the polyethylene had already melted and was sufficiently mixed with the wood flour and integrated. After allowing it to cool naturally, it was crushed into approximately 10 mesh pieces using a crusher, placed in an aluminum formwork treated with fluororesin, and then crushed under a pressure of 5 kg/cm using a heat press machine.
d. Heat and pressure was applied at a temperature of 160° C. for 7 minutes, deaerated, and cooled to obtain a synthetic wood board with a thickness of 6 mm and a specific gravity of 0.78.

Claims (1)

[Claims] Thermoplastic synthetic resin and wood powder, granules, or fibers are kneaded for a short time using a heating kneader to fuse the resin to the wood surface, then cooled and crushed appropriately. A method for manufacturing synthetic wood boards, in which the wood is uniformly supplied onto a hot plate or formwork, and then pressed and heated using a heat press to form a board.