Because of the physical properties, chemical properties of plastics and other materials are different, therefore the design of injection molding products also has its unique side, generally speaking, the basic principle of plastic design of structural components are as follows.
  1.shapes simple, elegant. To meet the requirements of the use of plastic case, plastic parts of the structure as simple as possible, in order to facilitate the molding. Therefore, injection molding products and the shape of the surface should be conducive to remove the plastic mold, then using the least possible petals parting mechanism, the core pulling mechanism of complex structure. In addition, in shape but also pay attention to plastic parts of the beautiful shape, material saving, do everything possible to reduce the manufacturing cost of plastic parts.
  2.according to the purpose of use and selection of materials. The intensity of work, the working conditions differ in thousands of ways, the load is big is small, high and low temperature, corrosion resistance is strong or weak and so on, therefore, need according to the plastic parts used to consider: one is to consider the physical properties of plastics, such as strength, stiffness, toughness, moisture absorption, the stress sensitivity; two is to consider the molding process of plastic, such as liquidity, shrinkage rate, crystallization rate, the forming temperature and pressure sensitivity etc.. Types of plastics greater diversity, its performance is also different, therefore, in the choice of materials must be carefully, carefully select. Such as the production of small household electrical appliances available heating, heat resistance of PSF plastic; bearing and working in high temperature, should heat resistance 260 degrees PI; if you need yo good mechanical properties, the PA should be the first choice.
  3.consider the process characteristics of injection time. Into the melt plastic melting, melt into the cavity formed plastic parts, the melt fluidity, shrinkage rate, the crystallization rate of temperature and pressure sensitivity and so on are very different, therefore, the structure of plastic parts should take full account of these characteristics. Such as plastic parts of the structure is complex, requires good fluidity of plastics, such as PA, PE etc.; such as small deformation, available PS, HPVC etc..
  4.consider the process of mould. Plastic is plastic molding die, die cost is often very high, making difficult. Therefore, the mold processing industry is particularly important: first, all parts can be processed on the mold; secondly, the workpiece with the expectations of performance and service life of the parts, anti-corrosion requirements should be selected with anti-corrosion performance materials or take anticorrosion measures, such as chrome, blue; third, mould should have versatility and interchangeability, so that the mold repair, replacement and manufacturing.
  5.should be conducive to simplify the mould structure and components. The die structure is usually more complex, this complexity increases the difficulty and cost of mold manufacturing, therefore, in the models to achieve the same use requirements of the situation, the structure of plastic parts design can have very big difference. Especially for the open hole, thread, placing the insert, plastic piece is provided with a concave convex surface, in the structure design should pay special attention to, if the improper design of the structure, not only can make the mould structure is complicated, and difficult to obtain needed can mold plastic parts.