Long with the grow of the market and the popularization of large injection machine, the demand of large part molding also grows up every year. The large part molding has the advantages as high productivity, good consistency of product, low cost in mass production.
However, it needs long development cycle and requires heavy investment on injection molding machine and mould. Specially, the large size mould is not the simply enlarge of middle and small mould. It has many differences in the mould design, manufacture and assembly. We need to pay special attention to the following points:
During the large part mould design, except for the strength, we also need to carefully calculate the mould’s rigidity. Considering the high injection pressure, large cavity size and high deformation, it’s necessary to strengthen the locating mechanism，cavity side plate and core bottom plate.
Since the L／￡ of plastic melt in large part mould is relatively high, and most of them use multiple gating hot runner, the design of mould injection system is critical. It could directly influence the melt pressure, melt temperature, filling process, holding process and many other elements. Also, it affects the product’s quality and the mould’s strength, rigidity and life span. Therefore, the injection system is the key object of the mould optimization. During the design process, we carefully analyze the system through mold flow analysis and other technologies.
For the large part mould design, we need to take the convenience of processing and maintenance into consideration. Since the large part mould has more troubles of processing, movement and installation, we could separate a certain of structure into several small parts or inserts. It helps to reduce the dependency of large processing equipment and lower the cost. Also, we could process multiple parts at the same time to improve the productivity.