The continuing development of injection-molding technology demands more and more of the processor. The most important problem in the process of injection molding is undoubtedly the correct design of the injection mold, because the molding shop has little influence, if any, on the construction of the machine. Efficient production of the most diverse injection-molded parts depends primarily on the injection mold.
The durability of the molds depends on their care and treatment. Since the moving components and cavity of the mold are always hardened and ground, they should produce between 500000 and 1000000000 shots.
For ease of construction and to lower manufacturing cost, injection molds are becoming standardized. Some firms offer ready-made bases of square or round design as standard or stripper plate molds for immediate use. Only the inserts then have to be fitted into the bases.
The decision concerning the number of of cavities to be determined depends on:
1) size of the order ( number of molded parts in connection with delivery time).
2) shape of the molded parts ( size, quality requirements).
3) injection-molding machine ( clamping force, plasticizing and injection capacity).
4) mod costs.
There are serveral known procedures for calculating the economical number of cavities. Unfortunately they are so varied that it is impossible to condense them.