Views: 0 Author: Site Editor Publish Time: 2022-08-03 Origin: Site
After the veneer is processed by the card-free rotary cutting machine, it must be dried to ensure that its drying degree is within a reasonable range. Why is this?
The main reason is that the cut veneer contains a lot of water. If it is not dried, it is directly glued and hot-pressed. Too much water will prolong the hot-pressing time, and it is easy to produce bubbling. Some types of glue cannot even be glued. Moreover, the dry shrinkage stress of plywood is very large, which is easy to deform and cause cracks in the veneer, which affects the quality. In addition, the wet veneer has a large water content, which is not conducive to stacking and storage, and the edges are prone to cracking or warping, and mildew is prone to occur in summer.
In fact, the dry moisture content of veneer should also be determined according to the requirements of tree species, rubber species and plywood, such as ash, etc. The early wood has large pipe holes, good air permeability and water permeability, and high water content has little effect on the bonding strength; Pine, etc., because the veneer contains a lot of rosin, the air permeability is poor during hot pressing, and if the final water content is high, it is easy to cause defects such as bubbling