Die casting mould design is reasonable or not will directly affect the plastic shrinkage rate, due to the mold cavity dimension is obtained by the estimate of the size of plastic products and shrinkage rate, and the shrinkage is or manual of engineering plastics as recommended by the plastic manufacturer of a range of values, it not only with the mold gate forms, gate location and distribution, and the crystal orientation of engineering plastics.
The process of plastic injection is the process of transforming plastic from solid state powder or granule into liquid and into solid product.Expect the melt from grain, again by the melt to the products, through middle temperature field, stress field, flow field and density field, in the field, under the joint action of different plastic thermosetting or thermoplastic, crystalline or non-crystalline, enhanced or not enhanced with different polymer structure such as morphology and rheological properties.
The factors that affect the above field will inevitably affect the physical and mechanical properties, size, shape, precision and appearance quality of the plastic products.In this way, the interconnection between the process factor and the polymer's performance, structure form and plastic products will be expressed through plastic products.It is of great significance to analyze these internal relations, and to reasonably design the injection molding process, rationally design and make the mould according to the drawing, and even choose the injection molding equipment reasonably.The precision injection molding is different from the injection molding pressure and injection rate. High pressure or ultra-high pressure injection and high speed injection are used to obtain the smaller shrinkage rate.
In addition to considering the design elements of the general mold, the following points should be considered in the design of precision injection mold.To prevent the formation shrinkage error;To prevent injection deformation;To prevent deform deformation;To minimize the manufacturing error of molds;To prevent the error of mould precision;Keep the mold precision.