Technique and equipment for lowering formaldehyde in procedure for processing lumber-core board

Abstract

The present invention discloses a formaldehyde-reducing process in the production process of veneered strip-glued board and its equipment. Said equipment mainly includes ventilating ducts and fan, and its formaldehyde-reducing process includes the following steps: spaced stacking the adhesive-coated mechanically-matched or hot-pressed board blanks, making the air inlets of ventilating ducts be positioned at two sides of board blank stack respectively, making the air outlets of ventilating ducts be positioned in the exterior of processing field, under the action of the fan a negative pressure action is formed around the board blank stack, so that the peripheral air of the board blank stack can be led out to the exterior of processing field so as to quickly discharge out free formaldehyde produced in the adhesive-coating process, and effectively prevent the free formaldehyde from being absorbed by board core and finished product board and can reduce formaldehyde content in the product obviously.

Description

technical field [0001] The technical solution of the present invention relates to the technical field of blockboard processing, in particular to the process of removing free formaldehyde in the process of blockboard processing and the equipment used in the process. Background technique [0002] In the existing blockboard processing technology, the processing of blockboard often adopts urea-formaldehyde resin adhesive. The advantages of using urea-formaldehyde resin adhesive are: low cost, high bonding strength, fast curing, and convenient use. However, due to: 1. The addition and polycondensation reaction of urea and formaldehyde in aqueous solution is a reversible reaction, and there will always be free formaldehyde in the glue; 2. There are methylene ether bonds in the resin. Decomposition produces formaldehyde, especially in the presence of moisture in acidic media, it is easier to decompose and release formaldehyde; 3. During the curing process of the resin, ether bonds ...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem that the free formaldehyde emission of existing urea-formaldehyde resin adhesives is too high, people's usual thinking is to develop adhesives with lower free formaldehyde content, such as the Meibang brand adhesive of the NR123T model, whose free formaldehyde content is 0.10%. The amount is 0.70mg / L

It belongs to the low urea-formaldehyde resin adhesive with low free formaldehyde content and low formaldehyde emission. The ordinary urea-formaldehyde resin adhesive and the low-formaldehyde content adhesive were compared in the experiment. High, it will have obvious adverse effects on the bonding strength, static bending strength and surface quality of the blockboard, and even make the product unable to meet the quality standards of GB / T5849-1999, thereby reducing the production efficiency and quality of the blockboard

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