Plastic mold injection molding method of rotational molding
Rotational molding, also known as rotational molding, is a processing method used to manufacture hollow seamless products of various sizes and shapes. Traditionally, it is mainly used on thermoplastic materials. In recent years, the rotational molding of thermosetting materials such as cross-linkable polyethylene has also developed rapidly. Since rotational molding does not require high injection pressure, high shear rate or accurate compound metering. Therefore, the mold and machine are relatively cheap and have a long service life. Its main advantages are: the performance/price of the machine is relatively high; the molding of complex parts does not require post-assembly; multiple products and multiple colors can be molded at the same time; the cost of the mold is low; the color and material are easy to change; and there is less loss of scrap.
The basic process is very simple. The powdered or liquid polymer is placed in the mold, heated and rotated around two vertical axes, and then cooled. At the beginning of the heating stage, if a powdered material is used, a porous layer is formed on the mold surface, and then gradually melts with the circulation process to form a homogeneous layer of uniform thickness. If a liquid material is used, it first flows and coats the mold surface, and stops flowing completely when the gel point is reached. The mold is then transferred to the cooling area, cooled by forced ventilation or water spray, and then placed in the work area, where the mold is opened, the finished part is taken away, and then the next cycle begins. Stainless steel welding rods. Plastic molds follow rigorous production processes and strict quality control systems to produce stable product quality. They mainly produce water conservancy plastic molds, water conservancy slope protection plastic molds, rice seedling trays and other molds.