1. Rotational molding
1) The wall thickness of roll molded products is uniform, and there is no corner waste or weld; Products with a wide range of wall thickness can be rotational molded, such as polyethylene rotary molded parts, with a wall thickness range of 1~16mm. However, due to the viscosity relationship, it is difficult to form thick wall products. The rotary molding process is particularly suitable for molding 2-5mm plastic products.
2) Usually, only hollow products or shell products can be produced, and it is difficult to process solid roll molded products. Moreover, the surface condition of rotational molding products has a great dependence on the surface of the mold cavity.
3) The dimensional accuracy of rotary molding products is relatively low, and its dimensional accuracy is usually ± 5%.
2. Rotational molding process
1) It is suitable for molding large and extra large parts. Because the rotational forming process only requires that the strength of the frame is enough to support the weight of materials, rotational molding die and the frame itself, as well as the closing force to prevent material leakage, even if processing large and oversize plastic parts, it does not need to use very heavy equipment and molds. Therefore, theoretically speaking, there is almost no upper limit on the size of products made by rotary forming process.
2) It is suitable for the production of many varieties and small batches of plastic products - because of the simple structure and low price of the mold used for rotary molding, it is very convenient to change products.
3) It is suitable for processing large hollow products with complex shapes, which is unmatched by other molding processes;
4) It is easy to change the color of plastic products. When it is necessary to change the color of products, just clean the molding mold.
5) The main disadvantages of rotary molding are: large energy consumption, because in each molding cycle, the rotational mold and mold base need to undergo repeated heating and cooling; The forming cycle is long. Because the plastic mainly conducts heat under static state, the heating time of rotary forming is long; The labor intensity is high, and the dimensional accuracy of products is poor.
