As a mold design engineer, it is necessary to have a clear understanding of the basic functions of an injection mold.

(1) Shaped product The shape of a plastic product is formed by stacking all the modules in contact with the plastic in a mold. The shape of general plastic products is divided into one of the following three situations or their combination: common practical shape; artistic shape; engineering (functional) shape. Mold designers must understand that designers of plastic products are not necessarily familiar with the complexities of mold making and molding processes. Some simple requirements in product design may cause difficulties in mold making and molding. Generally, minor structural changes in the product will greatly simplify the mold or improve molding conditions.

(2) The transport of plastic from the injection machine to the cavity The following discussion is applicable to the entire gating system. According to the state of the plastic melt in the gating system, it is divided into two major categories of cold runners and hot runner systems.

(3) The discharge of air from the mold cavity during filling is accompanied by the appearance of pouring molding. The importance of the exhaust gas is recognized. For the mold designer, sufficient exhaust should be taken into account from the very beginning, poor exhaust will cause burning or burning of the plastic, plastic can not fully fill the cavity space, resulting in cavitation and other consequences. Generally, at the parting surface of the mold, if the clearance between the top rod and the top sleeve of the mold core can provide a natural exhaust place, the effect of the poor exhaust gas is not very obvious for general low speed injection.

(4) The plastic cooling mold is a heat exchanger - the plastic is obtained in the injection machine. Most of the energy (heat) that melts and is suitable for injection must be dispersed before the mold is opened to eject the plastic product. Must be hardened to meet the eject requirement. The cooling time of products generally accounts for 70%-80% of the entire molding cycle. Therefore, the key to a good mold is the quality and efficiency of the cooling settings in the module and the template. It is actually the amount of heat that can be exported per second. , and cannot be made too complicated and costly.

(5) The key to the ejection of plastic products is reliability. The mold should work properly within 100% of the time. In industries where a large number of automatic molding operations exist, such as in the automotive industry, it should be avoided that the products cannot be topped out.

(6) Economical production and proper requirements Before starting the mold design, it is very important for designers to fully understand the actual requirements of the mold and the scale of mold production. The type of mold and the number of cavities are the basis for determining the structure and size of the mold.