SU973396A1 - Method of manufacturing fibreboard panels - Google Patents

Description

(54) METHOD OF MANUFACTURING WOOD-FIBER TILES

one

The invention relates to the woodworking industry, in particular to the production of fibreboard.

A known method of manufacturing wood boards, comprising molding the carpet and pressing 1.

The disadvantage of this method is the insufficient strength of the plates and the need for an additional technological operation - heat treatment.

A known method of manufacturing fibreboard includes forming a carpet, pressing, processing with drying oils 2.

The disadvantage of this method is the presence of two additional technological operations — impregnation and heat treatment of the plates, which complicates the technology and increases the cost price of the plates. In addition, additional significant floor space is required to accommodate the impregnating plant and the heat treatment chambers with rail tracks to move the racks with the impregnated slabs.

The purpose of the invention is to increase the strength of the plates and simplify the manufacturing technology.

The goal is achieved by the fact that drying oils are mixed with a polyvinyl acetate dispersion in the following ratio of components, wt.% / O:

Drying oils20-70;

Polyvinyl acetate 10 dispersion 30-80

the resulting mixture is applied to the surface of the carpet before pressing.

Example 1. Take aspen fibers obtained on industrial equipment of the line and process them with resin SFL-3014 in the amount of 4% (on dry matter) to the weight of absolutely dry fibers in a mixing drum. Next, the fibers are dried in a pneumatic dryer to a moisture content of 7-9%. Carpet formation is carried out on a vacuum-forming machine. After that, the carpets are pressed in a cold press at a pressure of 2.5-3.0 MPa.

Then onto the surface of a fiberboard carpet just before the hot

pressed by spray gun with p. (food, no additives, wt. ° / Drying oil70

Polyvinyl acetate

dispersion 30

Polyvinyl acetate dispersion is diluted before use to a concentration of 35% (the concentration of commercial PVAD is 52%), which is caused by the need to reduce the viscosity to a value that allows the application of PVAD to the surface of a plastic carpet ..

Fiber boards are pressed at 200 ° C with a pressing time of 1 min / mm. Slabs. Get 6mm thick. The plates are not heat treated.

Example 2. The operation of the method of hardening the surface layers of fibreboard similar to example 1, but with the ratio of the components of the composition, wt.%:

Drying oils50

PVAD50

Physicomechanical indicators of fibreboards made by various methods of surface layer hardening

Plates soaked with tall oil fatty acids and heat-treated ,.

consumption of impregnating composition - 720 g per 1 m of the surface of the plates (prototype)

Durability

Example 3 Same as in example 1, but with a ratio of the components of the composition, .Mac.i ,. Drying oils20

PVAD80

The test results of fibreboard are presented in the table, the data in the table indicate an increase in the strength characteristics of fibreboard compared to the prototype. In addition, the paint-and-lacquer coating on the samples of the plates made according to the invention is even, smooth and glossy and better than that of the impregnated plates (of the prototype), while reducing the consumption of hardening additives by 3 times, simplifies the process ), the cost of plates decreases, labor productivity increases and labor costs are reduced, production space is saved (equipment for impregnation and heat treatment of plates is eliminated), electricity is saved.

The number of substances applied to 1 m of the surface of the carpet, g

A mixture of PVAD with tall oil fatty acids 200200 I 200

The ratio of components

80:20

50:50

30; 70

Claims (1)

Claim A method of manufacturing wood fiber _: wet boards, including carpet molding, pressing, processing with drying oils, characterized in that, in order to increase the strength of the boards and simplify manufacturing techniques, drying oils are mixed with polyvinyl acetate dispersion in the following ratio, wt.%: Drying oils 20–70 Polyvinyl acetate dispersion 30-80, VNIIIPI Order 8119/1 Branch of the Patent Production and Commercial Enterprise, the city of which the resulting mixture is applied to the surface of the carpet before pressing.