Polycarbonate sheet production process

The production process of the PC board is extrusion molding, and the main equipment required is an extruder. Because the processing of PC resin is difficult, the requirements for production equipment are high. Most of the domestic equipment for the production of PC boards is imported, most of which are from Italy, Germany and Japan. Most of the resins used were imported from GE in the United States and Baver in Germany. Prior to extrusion, the material should be thoroughly dried to a moisture content below 0.02% (mass fraction). Extrusion equipment should be equipped with a vacuum drying hopper, sometimes several in series. The fuselage temperature of the extruder should be controlled at 230-350 ° C, gradually increasing from the back to the front. The handpiece used was a flat-slit slit head. After extrusion, it is cooled by calendering. In recent years, in order to meet the requirements of UV resistance of PC boards, a thin layer containing UV-resistant additives is often applied to the surface of PC boards. This requires a two-layer co-extrusion process, that is, the surface layer contains UV additives. The bottom layer does not contain UV additives. The two layers are compounded in the nose and integrated into one after extrusion. This type of machine head design is more complicated. Some companies have adopted new technologies, such as Bayer's technology with specially designed melt pumps and combiners in co-extrusion systems. In some cases, there is no requirement for dew drops on the PC board, so there should be an anti-dew coating on the other side. There are also PC boards that require UV-resistant layers on both sides. This PC board production process is more complicated.