Process of using polyurethane tackifier to improve prepressing strength of formaldehyde-free artificial board

Abstract

The invention provides a process of using a polyurethane tackifier to improve prepressing strength of a formaldehyde-free artificial board. The process includes following steps: step 1, smashing cropstalk to be 20-50 meshes in fineness, adding polymerization MDI glue accounting for 2-8% of weight of the crop stalk and the polyurethane tackifier accounting for 1-5% of the weight of the crop stalk,stirring and mixing, and paving to form a board blank; step 2, adopting a continuous prepress to press-roll the board blank at pressure of 250-500kN / m2; step 3, feeding the board blank into a hot press for hot-press curing at hot pressing temperature of 150-220 DEG C and at pressure of 2400-3800kN / m2 to form a rough board, and performing aftertreatment on the rough board to obtain the artificialboard.

Description

technical field The invention relates to the technical field of wood-based panels, in particular to a process for increasing the pre-compression strength of formaldehyde-free wood-based panels by using a polyurethane tackifier. Background technique The current reduction of formaldehyde emission from wood-based panels is the development trend of the wood-based panel industry. More and more manufacturers are researching and using the process of adding diphenylmethane diisocyanate (MDI) to produce wood-based panels to increase the strength of wood-based panels. The water expansion rate is reduced, so that it has a certain fireproof performance, and its formaldehyde emission is greatly reduced. However, since MDI itself is not viscous at room temperature, the cross-chain reaction occurs only under specific temperature and pressure conditions and is irreversible. Therefore, in the process of making slabs, it is basically impossible to form, and can only rely on the support of th...

AI Technical Summary

Problems solved by technology

Therefore, in the process of making slabs, it is basically impossible to form, and can only rely on the support of the liner to prevent loosening and loss of shape, so that the pressing process can only use intermittent pressing methods. The intermittent pressing method is inefficient and affects the production capacity of the production line. Usually, the same scale The production line is only one-third of the capacity of the conventional urea-formaldehyde glue production line, or even less

Images