Die-cast mold design have reasonable or not will directly effect plastic products of contraction rate, due to mold type cavity size is by plastic products size plus by estimates of contraction rate obtained of, and contraction rate is is by plastic production manufacturers or engineering plastics manual recommended of a range within of numerical, it not only and mold of poured mouth form, and poured mouth location and distribution about, and and engineering plastics of Crystal orientation sex.
Due to the injection process is from a solid plastic powder to the liquid melt and solid or granular product change process. Expect from the grains melts, then melt into products, to go through temperature field and stress field, flow and density field, such as the role in the interaction of these fields, different plastics thermoset or thermoplastic, crystalline and non-crystalline, reinforced or non-reinforced polymer with different structure and rheological properties.
Affecting these factors will affect the plastic products of physical and mechanical properties, size, shape, appearance, accuracy and quality. Thus, technological factors and performance, structure of polymer morphology and intrinsic link between plastics will be represented by plastic products. Analysis of these intrinsically linked, on the rational development of injection molding process and reasonable design drawings and manufacturing molds, injection molding equipment and reasonable selection of great significance. General injection molding and precision injection molding injection pressure and injection rate may differ on, precision injection often use high pressure or high pressure injection, high speed molding shrinkage for injection to get smaller.
Design of precise injection mold design elements, inter alia, take into account the General dies, must also consider the following: using the appropriate mould dimensional tolerances; II to prevent molding shrinkage errors; and aim at preventing plastic deformation about preventing mold deformation; II the mold manufacturing error to a minimum; ⑥ prevent mold of error; sadly, keeping precision molds.