JPH0467489B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a method for improving the water resistance of particle board.

[Conventional technology] Particle board, which is conventionally manufactured by mixing wood chips and adhesive and hot-pressing molding, undergoes significant dimensional changes due to moisture absorption and dehumidification, and is more susceptible to water than other wood materials. It had drawbacks. Conventional countermeasures have been to immerse the particle board in a paraffin wax emulsion and then dry it to evaporate the water to form a paraffin film on the surface of the board. A method has been proposed in which a particle board is immersed in water, the liquid drained, and then cooled to form a film on the board surface.

[Problems to be Solved by the Invention] Among the above methods, the method using a paraffin wax emulsion has the problem that paraffin particles adhere to the board surface in layers like fish scales.
It is difficult to form a uniform film after drying, and only a non-uniform film with many irregularities can be formed, which has the drawback of causing local differences in waterproof and moisture-proof performance.

In addition, in the method of using heated and melted paraffin wax, the paraffin wax is at least 85%
Although it must be heated to a high temperature of 135°C, paraffin wax is a semi-dangerous material as stipulated by the Fire Service Act, and there is a risk of fire due to heating and odor during work.
It has various problems such as burns.

[Means for Solving the Problems] Therefore, the present invention was made in view of the above problems, and after applying or permeating paraffin wax emulsion on particle board,
The present invention relates to a method for manufacturing water-resistant particle board, which involves heat treatment to evaporate moisture and melt paraffin, followed by cooling.

This invention will be explained in detail below.

The particle board used in this invention is a commonly used material made of wood chips coated with an adhesive and molded under heat and pressure.

The particle board is mixed with purified paraffin wax (melting point 66.1℃) with additives such as emulsifiers and surfactants to form an emulsion.The amount of paraffin wax added to the emulsion is 20 to 60% by weight. That's about it.

The emulsion is applied to the entire surface of the particle board or the end surface using a coating device such as a spray coater or flow coater, or by dipping the board in the emulsion in a container.

After applying or infiltrating the paraffin wax emulsion on the particle board, the temperature is 100-110℃.
The emulsion is heated at a certain temperature to evaporate water in the emulsion, and the heating is continued to melt the paraffin coated on the surface and form a paraffin film on the coated surface. The heating time is about 30 seconds to 20 minutes, using hot air or far infrared rays.
Alternatively, the treatment is completed by heating directly and then cooling to room temperature.

In this invention, the method of applying or permeating the paraffin wax emulsion to the particle board and then heating and melting it improves the permeability of the paraffin into the board compared to the method of directly heating the paraffin, and also reduces the risk of ignition. Except for gender,
This is to improve the working environment.

Examples will be described below.

[Example] Example 1 After spraying an emulsion containing 35% by weight of purified paraffin onto the side surface of a particle board with a thickness of 15 mm (solid content: approximately 50 g/m ² ), approximately
Heat treated in a hot press at 110℃ for 1 minute to evaporate moisture and create a paraffin film, and further heat to melt the paraffin and create a film.
Thereafter, it was taken out from the press and cooled at room temperature to complete the water resistance treatment.

Example 2 A particle board with a thickness of 12 mm was immersed in a container containing an emulsion containing 30% by weight of purified paraffin, then taken out and hot air was blown onto the board surface for 10 minutes using a hot air dryer at 100°C. to evaporate water and form a paraffin film,
The coating was melted to create a uniform paraffin coating on the surface layer of the board, and then cold spray was applied to cool the surface.

[Effects of the Invention] In this invention, as described above, emulsion-type paraffin wax is applied or impregnated onto particle board and then heat-treated to form a molten film. Compared to the method of applying Tux to evaporate water and forming a paraffin film, this method not only evaporates the water, but also heats it up to melt the paraffin and then cools it, so it forms a uniform and flat paraffin film. be able to.

In addition, compared to the method of dipping the particle board in directly heated and melted paraffin, this method uses emulsion type paraffin wax, which allows the paraffin to penetrate into the board better, and because the paraffin wax is not directly heated. There is almost no risk of flying sparks, and the work environment is also good.

Claims (1)

[Claims] 1. A method for manufacturing water-resistant particle board, which comprises applying or impregnating a paraffin wax emulsion onto particle board, heating it to evaporate water and melting the paraffin, and then cooling it.