A process for reducing formaldehyde of medium and high density fiberboard

Abstract

The invention provides an aldehyde reducing technology for medium-high density fiberboards. The aldehyde reducing technology comprises the steps that 1, vacuum sealing is performed, wherein the medium-high density fiberboards are separately placed in a vacuum box capable of being sealed, and the vacuum degree of the vacuum box is regulated to negative 0.08-0.09 MPa; 2, ammonia fumigating and heat treatment are performed, wherein liquid ammoia is injected into a liquid storage tank located under the vacuum box in 0.5-1.0 kg / m<3> fiberboard, and meanwhile the vacuum box is heated and heat preservation at 60-80 DEG C and heat treatment for 20-60 min are performed on the medium-high density fiberboards; health maintenance is performed, wherein the out-taken fiberboards are stacked for ventilation and health maintenance for 3-7 days. According to the aldehyde reducing technology for the medium-high density fiberboards, the ammonia fumigating time is short, the liquid ammoia usage amount is less, the ammoia residue amount is low, the production cost is effectively lowered, and secondary pollution is prevented from being generated; the health maintenance time is short, and the production cycle is shortened; plastic film is not needed for covering and sealing in the health maintenance period, and the treatment cost of the fiberboards is lowered; the fiberboards processed through the technology is good in physical property and small in change, low in formaldehyde emission, stable in effect and small in rebound.

Description

technical field [0001] The invention relates to a formaldehyde reduction method for fiberboard, in particular to a formaldehyde reduction process for medium and high density fiberboards. Background technique [0002] Medium and high density fiberboard is a kind of man-made board made by mechanically separating and chemically treating wood or plant fibers, adding adhesives and waterproofing agents, etc., and then molding under high temperature and high pressure. It is an ideal man-made board for making furniture. The structure of medium and high-density fiberboard is more uniform than that of natural wood, and it also avoids problems such as decay and insects. At the same time, it has small expansion and contraction and is easy to process. Because the surface of medium density fiberboard is flat, it is easy to paste various finishes, which can make the finished furniture more beautiful, and it is superior to particleboard in terms of bending strength and impact strength. How...

AI Technical Summary

Problems solved by technology

This method has an obvious effect on reducing aldehydes, but the use of these adhesives will increase the water expansion rate of the fiberboard and reduce the moisture resistance. At the same time, it is more expensive than traditional adhesives, resulting in an increase in the cost of fiberboard.

[0005] 2) Adding formaldehyde remover to the adhesive to capture free formaldehyde molecules, this method has high requirements on the composition, dosage, and timing of adding the formaldehyde remover, which can easily lead to the scrapping of the adhesive; at the same time, the formaldehyde remover It can only remove the free formaldehyde generated during the glue making process, but cannot remove the formaldehyde generated by the hot pressing of fiberboard and the re-reaction of fiberboard in the later application

The aldehyde reduction treatment period adopted in this method is long, which reduces the production efficiency. Due to the high treatment temperature, the energy consumption is large.

Images