The raw materials for making customized Plain Particle Board include wood or wood fiber materials, adhesives and additives. The former accounts for more than 90% of the dry weight of the board. The wood raw materials are mostly derived from timber cut in the forest, small diameter timber (usually less than 8 cm in diameter), logging residues and wood processing residues. Processed into flakes, strips, needles, granular wood chips, shavings, wood wool, sawdust, etc., called scraps. In addition, non-wood materials such as plant stalks and seed shells can also be made into plates, and their names are often named after the materials used, such as hemp (particles) boards, bagasse (particles) boards, etc. Adhesives mostly use urea-formaldehyde resin glue and phenol-formaldehyde resin glue. The former has a light fat color and a low curing temperature. It has a good gluing effect on the customized Plain Particle Board of various plant materials such as wheat straw and rice husk. The hot pressing temperature is 195-210°C. The shape of shavings is a decisive factor in the quality of the customized Plain Particle Board, so qualified shavings must be manufactured first. The shavings leftover from wood processing can be used as the core layer of the customized Plain Particle Board after reprocessing. The surface layer shavings are mainly processed and made from high-grade residues (wood truncation, board edges, etc.) in the cutting or processing. The length, thickness, and width of the shavings vary depending on the production method and the core layer or surface layer. The processing equipment for preparing shavings includes a chipper, a shredder, a grinder and a fiber separator, and the cutting methods include cutting, cutting and crushing. In order to obtain high-quality shavings, it is necessary to go through the processes of primary crushing, grinding, re-crushing and screening. The shavings made by processing have an initial moisture content of approximately 40-60%, a moisture content of 2 to 4% for the core layer and 5-9% for the surface layer that meet the technological requirements. Therefore, it is necessary to use a dryer to dry the shavings with different initial moisture content to achieve a uniform final moisture content. The dried shavings are then mixed with liquid glue and additives. Usually 8-12 grams of glue is applied per square meter of surface area of ​​the shavings. The glue is sprayed from the nozzle into particles with a diameter of 8 to 35 microns, forming an extremely thin and uniform continuous glue layer on the surface of the shavings. Then spread the sizing shavings into a slab, the thickness of which is generally 10-20 times the thickness of the finished product. Pre-pressing and hot pressing can be carried out. The pre-pressing pressure is 0.2-2 MPa, and it is carried out with a plate press or a roller press.
The above is an introduction to the raw material knowledge of the customized Plain Particle Board.