Birch Throughout Plywood Inspections and QC checklists
In the plywood industry, some innovative enterprises have been working hard to learn the production process of plywood abroad and improve the quality of their products. The full birch plywood which has not been cared about by the industry is one of them. Because of its complex production, raw materials almost rely on imports, and are very vulnerable to the restrictions of raw materials, coupled with birch density, difficult to process, prone to various price defects. And its price is expensive, so it is difficult to promote in the domestic ordinary market.
If there is a real need, the production and quality control of full birch plywood should pay attention to the following points:
1. full birch refers to 100% birch wood, and all the veneers of face and core veneers are birch wood. birch face veneer normally 1.0mm to 1.4mm ,UPM WISA and SEVZA use 1.4mm ,but local markets are normally use 1.0mm to 1.2mm .
2. Quality, thickness and tolerance of birch veneer.
3. Is the thickness of birch face veneer the whole piece ?
4. The structure of core veneer is the traditional three-and-five-piece structure.
5. The use of formaldehyde glue, bonding strength, because birch wood is hard, the use of phenolic glue is recommended.
6. Pressure and time of hot pressing.
7. Whether the edge and inner veneer layers are clear or not, and whether the overlap is serious or not.
8. moisture content control.
9. In general,full birch plywood veneer is much thicker than poplar core birch plywood veneer. This can be seen from the raw materials of the factory, and can also be seen after polishing.
10. Grade of birch veneer