Plywood is a three-layer or multi-layer board-like material that is cut into veneers by Veneer Rotary Cutting Machine or planed into thin wood and then glued with an adhesive. Usually, odd-numbered veneers are used and adjacent layers are made. The fiber orientations of the veneers are glued perpendicular to each other. Plywood is often used in the production of furniture, quick packing, and steel side boxes. The use of a large amount of adhesive can easily cause the formaldehyde emission to exceed the standard. Therefore, the environmental protection of plywood is very important when people choose furniture. Plywood has great strength, good flexibility, medium density fiberboard material is relatively uniform, suitable for production and processing, is one of the three major boards of artificial board, then what causes the deformation of plywood, then follow the Hot Press Machine Supplier will tell everyone.
1. Deformation caused by differences in water content in parts of the interior.
In the production of plywood, such as chipboard, medium-density fiberboard fiber parts are unevenly dried or uneven during the entire sizing process. Veneer coating is uneven in plywood production. There are differences in water content, curing of glue, and evaporation of water content. The stresses are uneven and cause deformation.
2. Deformation caused by improper hot pressing process or the influence of the press itself.
During the whole process of plywood pressing, due to the conditions of the Hot Press Machine, such as deformation of the pressing plate, insufficient temperature of the individual hot pressing plates, or deformation caused by uneven pressure, or improper control of the hot pressing process, the temperature is too high or too low, deformation caused by too much pressure.
Hot Press Machine
3. Deformation caused by structural asymmetry.
Structural asymmetry is a key factor that causes stress in the plate. For example, the surface and backing particles of MDF and particleboard are different. The upper and lower sides of the plywood neutral layer are different from the tree species, veneer fiber arrangement orientation, thickness, moisture content, number of layers, and production methods. The board has twists and so on, which is also the key reason for warping deformation.
The above is the main reason for the deformation of the plywood, I hope to help everyone.