Production process of Particleboard
According to the different slab forming and hot pressing equipment, the production methods of particleboard are divided into intermittent flat pressing method, continuous extrusion method and rolling method. In actual production, the flat pressing method is mainly used. Hot pressing is a key process in particleboard production. Its function is to solidify the glue in the slab, and consolidate the loose slab into the plate of specified thickness after pressing. The process requirements are: ① appropriate moisture content. When the surface water content is 18-20%, the bending strength, tensile strength and surface finish are improved, and the possibility of bubbling and delamination is reduced. The moisture content of core layer shall be lower than that of surface layer to maintain proper plane tensile strength. ② appropriate hot pressing pressure. The pressure can affect the contact area between the particleboard, the thickness deviation of the board and the transfer degree of the glue between the particleboards. According to different density requirements of the product, the hot pressing pressure is generally 1.2-1.4 MPa. ③ proper temperature. If the temperature is too high, not only the urea formaldehyde resin will decompose, but also the slab will be solidified in advance and waste products will be produced. ④ appropriate pressurization time. If the time is too short, the middle resin can not be fully cured, the elastic recovery of the finished product in the thickness direction increases, and the plane tensile strength decreases significantly. After hot pressing, the moisture content of particleboard should reach the equilibrium state after a period of conditioning treatment, and then it should be sawed, sanded and inspected for packaging. However, hot stacking is not allowed after pressure relief, otherwise the brittleness of plates will be increased. Molding technology refers to the technology of forming products in one operation. There are three mature processes. The hot mold method can be used with little or no glue, and can play the role of gluing by the activation and flow of lignin in the closed hot mold. However, it needs to be cooled and demoulded, with large heat consumption and low productivity, which has been gradually eliminated. The box forming method is to use a special press to pressurize and press products once, which is used to manufacture packing boxes. The hot pressing method is mainly used to manufacture furniture accessories, interior decoration accessories and pallet. The adhesive is mainly urea formaldehyde resin. The surface of the product is pasted with single board or resin impregnated paper, forming in one time. In addition, there is also a plane molding method for pressing the surface of the particleboard or the formed slab without hot pressing to make relief pattern.如无特殊说明，文章均为本站原创，转载请注明出处。If there are no special instructions, the articles are original, if you want to use or reproduce, please indicate the original source www.plywoodinspection.com,If you find that our articles infringe on your copyrights and interests, please email us at email@example.com in time and we will delete it at the first time.