A kind of preparation method of flame retardant plywood

Abstract

The invention discloses a method for preparing flame-retardant plywood, and relates to the technical field of wood-based panels. The invention utilizes the layer-by-layer self-assembly technology and utilizes the electrostatic interaction between anion and cation polyelectrolytes to construct a flame-retardant layer on the surface of a wood veneer, and then prepares a flame-resistant plywood by sizing, hot pressing, and other processes. The preparation method of the flame-retardant plywood, the limiting oxygen index (LOI) of the plywood prepared by the method is as high as 33%-43%, and the bonding strength is as high as 0.75MPa-1.25MPa, which meets the requirements specified in GB / T 9846-2015 "Ordinary Plywood" The glue strength requirement standard (0.7MPa) of type II plywood, the amount of flame retardant added is only 3-13%, which realizes high-efficiency flame retardancy, and this method can quickly adapt to the existing production process and technology of plywood, and has a relatively Good marketing value.

Description

technical field [0001] The invention relates to the technical field of wood-based panels, in particular to a method for preparing flame-retardant plywood. Background technique [0002] Plywood is a type of man-made board made of wood veneers by applying adhesive, forming blanks, pre-pressing and hot-pressing. In 2018, the output of plywood in my country was 178.98 million m 3 , accounting for 60% of the total wood-based panel production. Mainly used in furniture, decoration, shopping malls and transportation, etc. Plywood is a combustible material, which is easy to cause fire. Due to the implementation of the national standard GB20286-2006 "Requirements and Marking of Flame Retardant Products and Components in Public Places", it has entered the public The plywood in the site must have the corresponding flame retardant performance level. The flame retardant treatment of the plywood can effectively improve the flame retardant performance of the plywood and expand the function...

AI Technical Summary

Problems solved by technology

[0003] 1. Impregnation of flame retardant solution treatment, the wood veneer is directly impregnated with a certain concentration of flame retardant solution by atmospheric pressure impregnation or pressure impregnation, and then dried, sizing, billet forming, pre-pressing and hot pressing. Prepare plywood, or impregnate plywood directly. The plywood obtained by this method has better flame retardancy, but the disadvantage is that the impregnated flame retardant solution will change the physical and chemical properties of the veneer or the glue layer, which will have a certain adverse effect on the bonding performance, and the flame retardant The amount of flame retardant solution is relatively large, and the disclosed invention patent CN101412231 B has prepared flame retardant plywood by impregnating the flame retardant on the veneer, but the concentration of the flame retardant solution used is high, which increases the cost of raw materials

[0004] 2. Use adhesives containing flame retardants, and add flame retardants and other additives to wood adhesives in a blended manner. This method is easy to operate and can directly obtain flame retardant properties during the plywood preparation process. The disadvantage is that the flame retardant will have a negative impact on the physical and chemical properties and bonding performance of the adhesive, and the flame retardant only exists in the glue layer, and the overall flame retardant effect of the plywood is not good. The disclosed invention patent CN 101892020 B uses melamine derivatives and The boron compound prepared flame retardant, added the flame retardant to the adhesive, and prepared the flame retardant plywood. However, the patent did not state that the bonding strength of the flame retardant plywood could reach the strength requirement of Class II plywood of 0.7MPa

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