JPS6012921B2 - Method for manufacturing synthetic resin injection treated wood materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a synthetic resin injection-treated wood material in which a synthetic resin liquid is injected into a wood material such as a wood material, a thin plate, a chip, etc. and cured.

Conventionally, synthetic resin injection-treated wood (hereinafter referred to as W.P.C.), which is obtained by injecting and curing a synthetic resin liquid into wood materials such as wood boards, can be used by selecting the type of synthetic resin liquid to be injected. , it is possible to obtain a material with improved physical properties such as abrasion resistance, water absorption and hygroscopicity, hardness, weather resistance, dimensional stability, and strength compared to ordinary wood, but when injecting the synthetic resin liquid, due to the structure of the wood, The synthetic resin liquid is most easily injected from the end surface of the wood, and from the plank or straight-grained surfaces, the cell edges of the wood cells inhibit the movement of the synthetic resin liquid, reducing the proportion of the synthetic resin liquid being injected into the interior of the wood. In order to uniformly inject the synthetic resin liquid, a long injection time was required. ``Also, because W.P.C. has an uneven distribution of the cell structure of the wood itself, the synthetic resin liquid that is injected also has an uneven distribution, and there are areas where a large amount of synthetic resin liquid is injected. There are parts where only a small amount is injected, and when viewed as a whole, there is a drawback that insufficient injection or uneven injection tends to occur.

Furthermore, W. P. C is because the distribution state of the injected synthetic resin liquid is greatly influenced by the distribution state of the cell tissue of the wood.
It has been difficult to inject a larger amount of synthetic resin liquid into a desired part of the wood than in other parts to particularly strengthen that part or to increase its transparency to change its cosmetic properties.

In order to solve these drawbacks and problems, the present invention has the following features:
W. P. When manufacturing C, external pressure is applied to the wood material to be injected by appropriate means to an extent that does not cause permanent deformation of the appearance to cause cracks in the wood cells, and then synthetic resin is applied to the wood material. By injecting and curing the liquid, it is possible to shorten the injection time of the synthetic resin liquid into the wood material, eliminate insufficient injection of the resin liquid, and further increase the amount of synthetic resin liquid injected into a desired part of the wood material. The present invention provides a method for producing synthetic resin injection treated wood material.

Wooden materials used in carrying out the method of the present invention include wood planks, sticks, thin plates such as veneers, laminates made by laminating and integrating thin plates, and wood chips made of wood with adhesive. There are particle boards made by bonding.

First, external pressure is applied to such a wood material by an appropriate means to cause cracks in the wood cells. External pressure can be applied by compression using a flat plate press, roll press, etc., impact using a hammer, etc., or vibration pressure using ultrasonic vibration. These methods are selected and adopted depending on the size and shape of the wood material. can. The external pressure may be applied to the wood material either during the drying period or during the drying period.
Cracks in wood cells caused by external forces refer to cracks in the cell membrane of wood cells, separation of intercellular layers, cracks in the pore membrane, etc. Such cracks in wood cells can be caused by relatively low pressure. can.

Therefore, even after such treatment, no permanent deformation occurs in the appearance of the wood. That is, wood exhibits strong resistance to tensile forces, but not so strong to compressive forces, and especially to lateral compression in the direction of the conduit, wood exhibits strong resistance to tensile forces.
Even when there is no noticeable change in appearance due to the low stress of about 3, conduits and tracheids are crushed, and cracks occur in cell walls due to buckling and shark bending.

Wood cells that have been deformed by applying external pressure in this way recover a considerable amount of deformation when the external pressure is removed, and although there appears to be no change in appearance, many cracks have formed in the cell walls. These cracks make it easier for the synthetic resin liquid to be injected later to move inside the wood, allowing the synthetic resin liquid to be injected deep into the wood in a relatively short period of time.

Such cracks in wood cells may be generated widely throughout the wood material by applying external pressure to the entire surface of the wood material, or
External pressure may be applied intensively to a desired area to generate the wood cells only in that area. The wood material in which cracks have been generated in the wood cells is then subjected to injection treatment with a synthetic resin liquid. The synthetic resin liquid used for injection is selected appropriately depending on the application, and may be either an addition polymerization type or a striped polymerization type synthetic resin liquid, and an appropriate plasticizer, A coloring agent, a curing accelerator, etc. may be added.

As a method for injecting the synthetic resin liquid, a vacuum method, a vacuum pressurization method, a concentration method, and other appropriate methods can be employed.

After the synthetic resin liquid is injected into the wood material, the injected resin liquid is cured, and the curing method is not particularly limited and may be performed by heating, irradiation with radiation, or other means. In this way, when a synthetic resin liquid is injected into a wood material that has cracks in the wood cells, the synthetic resin liquid is injected into the interior of the wood cells through the cracks and forms the wood without being inhibited by the cell walls. The injection time can be shortened by uniformly injecting the material into the interior of the material.

In other words, if the wood material is a wood board, for example, the synthetic resin liquid is most likely to be injected from the end surface of the wood board due to the wood structure, and the cell walls inhibit the movement of the synthetic resin liquid from the grain or straight-grained surfaces. However, in the method of the present invention, such obstructions caused by cell walls are reduced, so resin liquid can be easily injected into both wood grain and straight grain surfaces, making it easier to inject. This makes it possible to shorten the time required for processing.

Furthermore, according to the method of the present invention, the injected resin liquid can easily move within the wood cells in areas where external pressure is applied to cause cracks in the wood cells, so the injection of the synthetic resin liquid in these areas may be uneven. The distribution state of the resin liquid can be made uniform without causing insufficient injection, and the W.I. P. C can be obtained.

Furthermore, according to the method of the present invention, it is also possible to partially apply external pressure to a desired part of a thick material to cause cracks only in the wood cells in that part. The injection speed of the synthetic resin liquid is faster than in other parts, and even with the same injection time, the amount of synthetic resin liquid injected into that part is larger than in other parts, increasing the strength, hardness, transparency, etc. of the part. W. P. C material can be obtained.

Therefore, W. P. When C material has joints such as screw holes and is used for furniture, etc., external pressure is applied to the part of the wood material corresponding to the joint in advance to generate cracks in the wood cells, and then synthetic resin liquid is injected. By processing, one piece of W
．． P. Even with C material, it is possible to obtain a bonded portion with particularly high strength and hardness.

Furthermore, the amount of resin injected into any part of the wood material can be increased due to the occurrence of partial cracks in the wood cells, resulting in a W. P. It is possible to vary the transparency of C, and it is also possible to create an arbitrary pattern based on the difference in transparency.

Next, specific examples of the present invention will be shown. Example 1 A straight-grain sliced veneer of Japanese pine with a thickness of 1.5 sides, a medium length of 10 cm, a length of 2 skins, and a moisture content of 7% was cold-pressed to 60k9.
Temporarily compressed within the elastic deformation limit under conditions of 15' for 15 seconds to cause cracks in the wood cells of the veneer without causing any apparent permanent deformation.

Next, this sliced veneer is placed in a vacuum cooker, the air is evacuated to 2&nm; The pressure was returned to normal and left for 1 hour to obtain a synthetic resin injection treated veneer.

Next, this veneer was hot pressed under the conditions of 13 pi○, 2 techniques, and 2k9/ground to harden the injected resin.
W. P. I got C single plate bad. - Comparative Example The same veneer as in Example 1 was treated with W.C. by injecting and curing a synthetic resin liquid under the same conditions as in Example 1 without performing pressure treatment by cold pressing. P. I got C veneer Tsukuda.

W.O. obtained in Example 1 and Comparative Example above. P. C veneer [
A comparison table of the physical properties of the mother is shown below. In the table above,
Wear resistance: Taper #280 with a load of lk9 2
Wear thickness when turning 0q Brinell hardness: The force required to dent a steel ball with a diameter of 1/m by 1/m Scratching hardness: Apply a load of 200 mm to a diamond needle to create a cotton-like coating on the surface. Synthetic resin ratio in the scratches when applied = W. P. Veneer weight after C-W
．． P. Veneer weight before C: XI.

〇W. P. This is the weight of the veneer before C.

As is clear from the above table, the W. P. C veneer ■ is W. P.
It can be seen that compared to C veneer {B'}, the amount of synthetic resin injected was larger despite the same injection treatment time, and the hardness and abrasion resistance were significantly improved.

Also, these W. P. When comparing the appearance of C veneer ■, W. P. C veneer [B] has lower transparency and is not much different in appearance from Japanese pine veneer before resin injection treatment, whereas W. P. C veneer has high transparency,
The color tones of the earlywood and latewood of the Japanese pine veneer were reversed, creating a beautiful grain pattern that was completely different from that of Japanese pine. Example
2. Touch the horn of an ultrasonic oscillator to the four corner surfaces of a particle board with a thickness of 15, medium 8 ratio, length 1.2, and a moisture content of 10%. 1 in day Z
By applying oscillating pressure for a minute, the wood cells of the wood chips at the four corners of the particle board are cracked, and then this particle board is placed in a vacuum oven and the inside of the oven is evacuated to 10 skin Hg to make it unsaturated. A synthetic resin solution having a ratio of polyester:styrene:BPO=50:50:5 was injected and left as it was for 30 minutes, then returned to normal pressure and left for one hour to obtain a resin-injected particle board.

Then, hot press this particle board for 13 minutes.
The injected resin was cured by hot pressing at 0°C, 5K9', and 50 minutes.

The thus obtained synthetic resin injection treated particle board had a larger amount of resin injected in the four pressurized corners than in other areas, and exhibited a highly transparent gradation color.

Next, this W. P. When screw holes were made in the four corners and the center of the C-shaped particle board, the resin liquid was injected into the four corner screw holes to the center of the board and the screw holes were sharp, but the screw holes in the center were sharp. The screw hole had a part in the center where the resin liquid was not sufficiently injected, the inside surface of the screw hole was rough, and the screw holding force was low.

As described above, according to the method of the present invention, a suitable external pressure is applied to the wood material in advance to generate cracks in the wood cell portion, and then the synthetic resin liquid is injected. The injection speed is increased and the time required to inject the synthetic resin liquid into the wood material can be significantly shortened, and it is possible to uniformly inject the synthetic resin liquid over the entire surface without causing insufficient injection or uneven injection. Therefore, synthetic resin liquid can be injected into the entire board in a relatively short period of time even if the length of the board is small.

In addition, by applying external pressure to a portion of the wood material, the amount of resin injected into that portion can be increased, so W.I. P. C material can be obtained.

Claims (1)

[Scope of Claims] 1. When producing synthetic resin injection-treated wood materials, which are made by injecting and curing synthetic resin liquid into wood materials such as wood materials, thin plates, chips, etc. 1. A method for producing a synthetic resin injection-treated wood material, which comprises applying an appropriate external pressure that does not cause severe deformation to cause cracks in wood cells, and then injecting and curing a synthetic resin liquid. 2. A method for producing a synthetic resin injection-treated wood material according to claim 1, characterized in that external pressure is applied to the entire wood material. 3. A method for producing a synthetic resin injection-treated wood material according to claim 1, characterized in that external pressure is partially applied to the wood material.