JPH1058413A - Manufacture of particle board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a particle board with good quality and excellent bending strength by a method wherein after water content of wood pieces is increased, foaming is performed while an isocyanate resin adhesive is sprayed and then, heat pressing molding is performed. SOLUTION: Wood pieces for a raw material of a particle board are prepd. and water content is adjusted to about 12-18wt.%, furthermore pref., about 15wt.% by spraying water thereon. Bonding of wood pieces each other is improved thereby caused by wetting of the surfaces of the wood pieces. Forming is performed while an isocyanate resin adhesive are uniformly sprayed on the wood pieces whose water content is increased like this and heat pressing treatment is performed by a hot press. The isocyanate resin, water and OH groups are reated with each other thereby to prepare a tough particle board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a particle board which releases a small amount of formalin after production and is easy to mold.

[0002]

2. Description of the Related Art Particleboard is formed by spraying a thermosetting synthetic resin adhesive such as a phenol resin, a melamine resin, a urea resin, a urea melamine co-condensation resin, and a guanamine resin on a wood chip obtained by dividing wood into small pieces. After that, it is manufactured by hot press molding, and is widely used for furniture, fittings, building materials and the like with its surface decorated.

[0003]

However, thermosetting synthetic resin adhesives such as phenolic resin, melamine resin, urea resin, urea-melamine cocondensation resin, and guanamine resin are synthesized using formalin. There has been a problem that formalin is released from the manufactured particle board or furniture, building materials, and the like manufactured from the particle board. Therefore, a method of producing a particle board using an isocyanate resin that emits little horimarin can be considered. However, since the isocyanate resin has a very low viscosity, the resin is usually spray-treated on a piece of wood having a water content of about 3 to 8% by weight to perform a belt conveyor. There is a problem that the forming mat formed above loses its shape due to vibration or the like when it is conveyed to a hot press and cannot be press-formed. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a particle board in which a forming mat is less likely to lose its shape and has high quality by using an isocyanate resin which generates less formalin.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
In the method for producing a particle board described above, after increasing the water content of a piece of wood, forming is performed while spraying an isocyanate resin adhesive, and hot pressing is performed. Claim 2
In the method for producing a particle board according to the first aspect, the water content of the wood piece is in a range of about 12 to 18% by weight.

[0005] In the method for producing a particle board according to the first and second aspects, before the isocyanate resin adhesive is sprayed, water is sprayed on the wood pieces so that the water content of the wood pieces is sufficiently higher than usual. Due to the wetting of the wood pieces by the spraying, the bonding between the wood pieces is improved, and the shape does not collapse due to the vibration after forming the mat. Further, at the time of hot pressing, the isocyanate resin reacts with water on the surface of the wood chip to form a urea bond, and the OH group of the wood chip (cellulose) also forms a urethane bond to form a particle board firmly.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described to provide an understanding of the present invention. First, a piece of wood to be used as a material for a particle board is prepared and sprayed with water to adjust the water content to about 12 to 18% by weight, and more preferably to about 15% by weight. This improves the bonding between the pieces of wood due to the wetting of the surfaces of the pieces of wood.

The isocyanate resin adhesive is formed while uniformly spraying the wood piece having a high water content as described above, and hot pressing is performed by a hot press. In this case, the application amount of the isocyanate resin is about 6 to 11% by weight based on the humidified wood chips. The hot pressing temperature is 100
The pressure is 10 to 15 kg / cm ² , and the pressing time is about 5 to 10 minutes. Thereby, as described above, the isocyanate resin reacts with water or OH groups, and a strong particle board is manufactured.

Although the above embodiment has been described with reference to a single-layer particle board, the present invention is also applicable to a multi-layer particle board, an OSB, and the like. In addition, it is free to add an additive for improving water resistance, an insect repellent agent, and an agent for imparting flame retardancy to the sprayed water or the isocyanate resin adhesive.

[0009]

In the method for producing a particle board according to the first and second aspects, since an isocyanate resin adhesive is used as the thermosetting resin, almost no formalin is generated. Furthermore, since the moisture content of the wood chips is increased,
Molding can be performed without losing shape, curing is promoted by the reaction of isocyanate resin adhesive, water and wood chips,
It is possible to manufacture a particle board of better quality and excellent bending strength.

Claims (2)

[Claims] 1. A method for producing a particle board, comprising: increasing the water content of a piece of wood, forming the composition while spraying an isocyanate resin adhesive, and performing hot pressing. 2. The method for producing a particle board according to claim 1, wherein the water content of the wood chips is in a range of about 12 to 18% by weight.