Hot pressing is a key process in the production of particleboard. The function is to solidify the rubber in the slab and to pressurize the loose slab to form a sheet of specified thickness. The process requirements are: 1 appropriate moisture content. When the surface water content is 18-20%, it is beneficial to improve the bending strength, tensile strength and surface finish, and reduce the possibility of slab bubbling delamination during pressure relief. The core layer moisture content should be suitably lower than the surface layer to maintain proper planar tensile strength. 2 appropriate hot pressing pressure. The pressure can affect the contact area between the shavings, the thickness deviation of the sheet and the degree of rubber transfer between the shavings. According to the different density requirements of the product, the hot pressing pressure is generally 1.2 to 1.4 MPa. 3 appropriate temperature. If the temperature is too high, not only the urea-formaldehyde resin will be decomposed, but also the slab partially solidified in advance to cause waste when the temperature is raised. 4 appropriate pressurization time. When the time is too short, the middle layer resin cannot be sufficiently cured, the elastic recovery of the finished product in the thickness direction is increased, and the plane tensile strength is remarkably lowered. After hot pressing, the particleboard should be treated for a period of time to adjust the moisture content to equilibrium, then saw sanding and inspection of the packaging. However, it cannot be stacked in a hot state after pressure relief, otherwise it will increase the brittleness of the board. Molding technology refers to the technique of forming a product in one operation. There are three mature processes. The hot mold method can use less rubber compound or no rubber compound, and activate the flow in the closed hot mold by lignin, and it needs to be cooled and demolded. The heat consumption is large and the productivity is low, which has been gradually eliminated. The box molding method is to pressurize with a special press and pressurize the product to make a package. The hot press forming method mainly manufactures furniture fittings, interior fittings and pallets, etc. The adhesive is mainly urea-formaldehyde resin, and the surface of the product is laminated with a veneer or resin impregnated paper, once formed. Further, there is a planar molding method in which a surface of a finished particle board or a formed slab which is not subjected to hot pressing is pressed with a stencil to form a relief pattern.
The shower niche is a space for storing and placing items. It is recessed on the wall and does not occupy the space of the bathroom. It has a very good expansion function. Our shower niche are made of high-quality stainless steel, which is strong and durable, not easily deformed, and has excellent decorative properties.
Showed Nich,Tile Shower Niche,Recessed Shower Niches,Shower Niche Tile JIANGMEN MEIAO KITCHEN AND BATH CO.,LTD , https://www.meiaogroups.com
Particleboard process