Method for improving weather resistance and mechanical property of bamboo plywood

Abstract

The invention discloses a method for improving the weather resistance and the mechanical property of bamboo plywood, and belongs to the technical field of bamboo processing. The method for improving the weather resistance includes the steps that a high-voltage electric field is applied when bamboo pieces coated with adhesives are assembled and hot-pressed, and the direction of the electric field is the same as the pressing direction of hot-pressing, and further includes the following steps of drying bamboo pieces, coating the treated bamboo pieces with the adhesives, assembling the bamboo pieces, hot-pressing and applying the high voltage electric field, shutting the high voltage electric field after reaching the hot-pressing time, pressure relief, cooling, and pre-forming and standby application. The method for improving the weather resistance and the mechanical property of the bamboo plywood can solve the problems of poor weather resistance, poor gluing property and mechanical property of the bamboo plywood, and has the advantages of low cost and high production efficiency.

Description

technical field [0001] The invention belongs to the field of bamboo board manufacturing technology, in particular to a method for improving the weather resistance and mechanical properties of bamboo plywood. Background technique [0002] my country has abundant bamboo resources. As a renewable biomass material, bamboo is manufactured into various bamboo board materials, which are widely used in construction, transportation, engineering decoration and other fields. It is an ideal processing alternative to steel and wood. one of the materials. During the utilization of bamboo wood-based panels, due to unreasonable processing technology, backward production technology, environmental dry and wet changes, and different properties from wood materials, bamboo plywood often suffers from board edge damage, delamination, and glue opening, which leads to The instability and inhomogeneity of the adhesive layer properties; on the other hand, in bamboo glued materials, there are three dif...

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Problems solved by technology

But its disadvantage is that it does not use urea-formaldehyde resin with poor bamboo gluing properties as the main adhesive, but uses phenolic resin with better gluing properties. ; The voltage of high-frequency pressurization is low voltage, which is only conducive to the movement and evaporation of water in the core layer adhesive, and improves the bonding efficiency of the core layer, but no broken chemical bonds and more cross-linking reactions are generated at the bonding interface, and it will cause Too much ineffective penetration of the adhesive can not effectively improve the bonding strength and mechanical strength, and increase the production cost

But its disadvantages are: high-frequency pressure only accelerates moisture migration and adhesive curing, and does not produce new broken chemical bonds and more cross-linking reactions, so it does not significantly improve the bonding strength and mechanical properties of the material; the whole The pressurization process is completed in a vacuum environment, which will generate a lot of energy consumption and increase production costs

But its shortcomings are: the high-voltage electric field voltage in the process of wood material preparation is 1kV to 10kV, this voltage range cannot improve the weather resistance of bamboo plywood, the reason may be that the bamboo surface contains fats, the chemical activity of the waxy layer, etc., For example, the simple use of doctrine cannot solve the problem of gluing on the surface of bamboo, and cannot improve the gluing strength of bamboo composite materials; The strength of its own, resulting in a reduction in the bonding strength of wood-glued materials

As a result, the use of high-voltage electric fields cannot effectively improve the mechanical properties of plywood materials.

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