来源：http://www.jnhjgs.cn 发布时间：2020-11-04 15:30:44 点击：
Rotational molding, also known as rotational 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, rotational molding of thermosetting materials such as crosslinkable polyethylene has developed rapidly. Since rotational molding does not require high injection pressure, high shear rate or accurate compound metering. As a result, both the polymer and the machine are relatively cheap and have a long service life. Its main advantages are: the machine performance / price is relatively high; complex parts do not need to be assembled after forming; a variety of products and colors can be formed at the same time; the cost of the mold is low; the color and material are easy to change; the loss of leftovers is small.
The basic process is very simple. The powder or liquid polymer is placed in a mold, heated and rotated around two vertical axes at the same time, and then cooled. At the beginning of the heating stage, if the powder material is used, a porous layer will be formed on the surface of the mold, and then gradually melt with the circulation process to form a homogeneous thickness homogeneous layer. If the liquid material is used, it will first flow and coat on the mold surface, and when the gel point is reached, the flow will stop completely. The mold is then transferred to the cooling work area, cooled by forced ventilation or water spray, and then placed in the work area, where the mold is opened and the finished parts are removed for the next cycle.