Visited and audited some china plywood factories , found that the multilayer plywood moisture content is strange, the veneer core substrate moisture content is not high, about 8 to 12, the four sides of the finished plywood moisture content is not high , Also 8% to 12%, but the middle part of the board moisture content is about 18% to 20%, this range is unacceptable. Because the board is easy to mold or easy to lose water and cause deformation.
After our QC team and the workshop production staff study and found that the problem was caused in the veneer hot pressing process, because the wood facev veneer hot pressing , the hot finished board has not been through a special shelves for heat exhaust/cooling and remove the moisture ,the water moisture content of the finished hot plywood Can not be timely discharge, resulting in a veneer finished board with high water content.Treatment method, it is recommended not to press the pressure, a short hot press drying. And then Put all the water out.
Or without hot pressing again, you can place the cut-plywood-strips in the middle of each two plywood to let the water evaporate out. But should pay attention to, not place the board by the second injury, place indentation, scratches and pollution.