Rotational molding, also known as rotary molding, is a processing method for manufacturing hollow seamless products of various sizes and shapes. Traditionally, it is mainly used in thermoplastic materials. In recent years, the roll molding of thermosetting materials such as crosslinkable polyethylene has also developed rapidly. Because rotational molding does not require high injection pressure, high shear rate or accurate compound metering. Therefore, the molding and machine are relatively cheap and have a long service life. Its main advantages are: high performance/price of the machine; The forming of complex components does not require post assembly; Multiple products and colors can be formed at the same time; The cost of mould is low; The color and material are easy to change; Less loss of leftover materials.

The basic processing process is simple. The powder or liquid polymer is placed in the mold, heated and rotated around two vertical axes at the same time, and then cooled. At the beginning of the heating stage, if powdery material is used, a porous layer is formed on the surface of the mold, and then gradually melts with the circulation process to form a homogeneous layer with uniform thickness. If liquid material is used, it flows and is coated on the surface of the mold first. When the gel point is reached, the flow stops completely. The mold is then transferred to the cooling work area, cooled by forced ventilation or water spraying, and then placed in the work area, where the mold is opened, the finished parts are taken away, and then the next cycle is carried out. Stainless steel electrode.