Analysis of the Structural Design of Rolling Mold
Rotational molding products cannot be formed without a rotational molding mold, which is a thin-walled shell with an inner cavity shape that matches the shape of the plastic product. For the convenience of demolding, one or more parting surfaces are set at the large cross-section of the product, and quick clamping fixtures such as C-shaped clamps are set at the parting area to ensure that there is no overflow during the molding process. After the molding is completed, the product can be quickly removed and re fed. At the same time, in order to exhaust the air that expands during the heating process and the large amount of gas generated by the decomposition of low molecular compounds in the molten material from the mold cavity, the rotary molding mold must be equipped with exhaust pipes on the mold cover or at the places with holes to prevent the mold from being compressed or the product surface from foaming.
Large rolling mold
The exhaust pipe is generally made of thin-walled metal fluoroplastic pipes, and the diameter of the pipe is determined by the size of the product and material properties (usually set at 10-12mm aperture per cubic meter of mold volume for thin-walled products). The length of the pipe should ensure that its end extends into the center of the mold cavity. To avoid resin powder overflowing from the exhaust port during rotation, the inner pipe opening should be filled with glass fiber, steel wool, graphite powder, etc. Each product has various forms of variation, including fully enclosed, open, and partially opened.
In order to reduce production costs, the first mock examination shall be designed for multiple purposes as far as possible, that is, different styles of products shall be produced through the disassembly and replacement of local parts under the condition that the large structure of the mold remains unchanged. In the mold, fluorine plastic (F4) or asbestos board are used to make insulation and insulation covers (small holes are plugged) lining the corresponding positions inside the mold, so that molten materials cannot stick to the mold. After cooling and demolding, open or partially open plastic parts can be obtained; By replacing this insulation cover with a metal cover, a fully enclosed component can be obtained.