JP2608753B2 - Particleboard manufacturing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a particle board, and more particularly, to a method for producing a particle board using an isocyanate-based resin adhesive, a hot press hot platen using an isocyanate resin adhesive. The present invention relates to a method for preventing chips from adhering to the.

[Prior Art] Conventionally, a water-soluble melamine resin adhesive or a water-soluble phenolic resin adhesive has been used for a particle board that requires a high degree of water resistance.

[Problems to be Solved by the Invention] However, among the conventional particle boards as described above,
When a water-soluble melamine resin adhesive is used, the irritating odor of free formalin released from the adhesive often causes problems in use and health. On the other hand, the particle board using the water-soluble phenol resin adhesive has less formalin odor than the melamine resin adhesive,
Since the pH of the adhesive itself is strong in the range of 12 to 14, the wood chips were alkali-contaminated, and the entire particle board was discolored to blackish brown.

Therefore, a method of producing a particle board using an isocyanate-based resin adhesive that does not generate a formalin odor has been implemented, but the isocyanate resin is slow to cure and has a thermoplastic property, so it is heat-melted. However, there is a problem in that workability is poor due to easy adhesion to the hot press hot platen.

In view of the above problems, the present invention has been made for the purpose of improving the adhesion of an isocyanate resin to a hot platen.

[Means for Solving the Problems] The method for manufacturing a particle board of the present invention is to prepare wood chips by preliminarily mixing and mixing an amino resin powder, and then applying an isocyanate resin adhesive to form chips. Next, the present invention relates to a method for producing a particle board which is heated and pressed by a hot plate.

The wood chips used in this invention are common chips obtained from Lauan, which is a southern timber, and pine and cedar, which are conifers, and are usually made in different sizes for the core layer and the surface layer, and have a water content of about 5 It is dried to about 5%.

Then, the wood chips are mixed with an amino resin powder.

The amino resin powder is a powder selected from synthetic resins such as urea, melamine, acetoguanamine and benzoguanamine.

When the amino resin powder is mixed with the wood chips, first, the chips are sprinkled with the amino resin powder while stirring to mix them as evenly as possible.

The mixing ratio of the amino-based resin powder to the chip was 0.1% in terms of solid content weight ratio based on the total dry weight of the chip.
It may be about% by weight.

Next, an isocyanate-based resin adhesive is applied to the chip mixed with the amino-based resin powder.

The isocyanate resin adhesive has a high solid content, and a commonly used adhesive that polymerizes and cures can be used.

The application amount is in a range where the weight of the resin solid content with respect to the dry chip weight is about 4 to 4.5% by weight.

Next, the chips to which the adhesive has been applied are formed into a mat shape (forming).

In the case where the entire chip shape is a single-layer particle board, the entire chip is processed by the method of the present invention. However, in the case of a multi-layer particle board, a fine-grained wood chip having a surface layer is used. Only the method of the present invention may be used.

Next, the formed wood chips are inserted between hot plates of a hot press and heated and compressed.

The pressing condition is ²⁰ ~ 40Kg / cm ² -150 ~ 170 ° C ~ 3 ~
It takes about 10 minutes.

[Operation] In the present invention, the isocyanate-based resin adhesive is applied after mixing and adjusting the wood chip and the amino-based fat powder in advance, because the isocyanate-based resin rapidly reacts with the amino-based resin and has heat resistance. It is known to make a high resin, but if the amino resin is mixed with the isocyanate resin adhesive, it becomes impossible to use it as an adhesive because the reaction proceeds too much. This is because, even if the chip to which the resin adhesive has adhered directly contacts the hot platen, it reacts rapidly with the amino resin to form a heat-resistant film, and does not easily adhere to the hot platen.

[Examples] Examples of the present invention will be described below.

(Example 1) Thickness 1 mm, length 5-6 mm, width 2 m adjusted to a water content of 7%
While stirring 16.1 kg of chips having a size of about m, 16.6 g of urea resin powder was uniformly mixed. Next, an isocyanate resin adhesive (solid content 100% conversion) was uniformly sprayed on the above chips in an agitating mixer about 4.5% by weight based on the total dry weight of the chips. Then, the chips to which the adhesive has been applied are formed into a plate by a forming apparatus, then inserted between hot plates of a hot press, and hot-pressed at 30 kg / cm ^{2 at} −160 ° C. for 5 minutes to obtain a single sheet. A layer of particle board was produced.

As for the particle board, the surface chips could be continuously hot-pressed without adhering to the hot plate of the hot press.

(Example 2) 1 mm in thickness, 5 to 6 mm in length, and 2 m in width adjusted to a water content of 5%
While stirring 10 kg of the chip having a size of about m, an isocyanate resin adhesive (in terms of solid content of 100%) was sprayed uniformly about 4% by weight based on the total dry weight of the chip to obtain a core layer chip. Next, 6 g of urea resin powder was added to and mixed with 6 kg of surface layer chips of 10 to 16 mesh through whose water content was adjusted to 7%.

Next, an isocyanate resin adhesive (in terms of a solid content of 100%) was uniformly sprayed on the above-mentioned surface layer chip in a stirring mixer at about 5% by weight based on the total dry weight of the chip. Then, the surface layer chip and the core layer chip to which the adhesive was applied were formed into three layers by a forming apparatus. Next, these laminated plates were inserted between hot-press hot plates and heat-pressed under the conditions of 30 Kg / cm ² -160 ° C.-5 minutes to produce a three-layer particle board to be obtained.

It was possible to continuously manufacture a particle board that does not generate a formalin odor, without the surface chips sticking to the hot press hot platen.

[Effects of the Invention] According to the method of the present invention, despite the use of an isocyanate resin adhesive, the surface chips of the particle board hardly adhere to the hot platen. It can be manufactured with good workability.

Claims (1)

(57) [Claims] 1. A particle characterized in that a wood chip is preliminarily mixed with an amino resin powder to prepare a wood chip, and then an isocyanate resin adhesive is applied to form the chip, and then the wood plate is heated and pressed by a hot platen. Board manufacturing method.