The requirements of injection mold design have?

The characteristics of the injection mould depends on the characteristics of raw materials, mainly include injection molding plastic melt flow characteristics of plastic injection and die cavity plastic cooling solidification shrinkage line of two points determine the particularity of injection mold and injection mold design difficulty. Because the plastic melt viscoelastic body, when the melt flow will change with shear stress, shear rate and viscosity, large molecules in the process of flow can produce direction along the flow direction, when the cavity is filled, melt part will be compressed, in the process of cooling solidification of plastic shrinkage will be very complicated, inside the cavity parts, plastic shrinkage rate is different in all directions, different kinds, brand of plastic shrinkage rate will be very different, in the same brand of resin or plastic processing, formula is different, its liquidity and fill shrinkage rate is different also. According to the characteristics of the injection mould in the design should fully understand the processing of plastic material properties, and the rational use of the design of injection mould, plastic effective use in the design process. Therefore, to consider the problems in the process of injection mold design is as follows.
1。 In-depth analysis of plastic parts structure and technology requirements. Plastic parts structure decision the injection mold structure of multifarious, plastic parts of the process requirement, Size precision, surface roughness, etc. ) Decisions for the manufacture of injection mold and molding process of difficulty coefficient, and thus do not meet the special requirements of plastic injection molding, the unreasonable structure shape, etc. , proposed the design of injection mold manufacturing and injection molding process of the difficulty coefficient.
2, familiar with the technical specifications of injection molding machine. Specification limits the size of the injection molding molding machines and the range of molding injection molding products.
3。 Understand plastic processing performance and process performance. Including the plastic melt flow, melt flow can reach the larger than: analysis of the flow resistance of all of the runners and cavities were, analysis the original air discharge inside cavity, plastic may occur in the injection mold crystal, direction and its internal stress, plastic cooling contraction and compensation, plastic requirement for injection mould temperature, etc.
4, taking into account the injection mold design and manufacturing, mainly solve the following problems.
, injection structure should be a reasonable choice. According to the drawings and technical requirements of plastic parts, study and choose the appropriate forming methods and equipment, combined with the factory machining ability, scheme of injection mold structure, fully solicit opinions from the relevant, analyzed and discussed, the design of injection mould structure is reasonable, quality is reliable, easy to operate. When necessary, can put forward according to the needs of the injection mold design and manufacture modified plastic parts drawings requirements, but the user must agree to implement.
b, the size of the injection molded parts should be calculated correctly. Molding pieces of plastic shape, size and surface quality is directly factors, relationship is very big, need special attention. When calculating the molding parts size, general average shrinkage method can be used. For high precision and the need to control forming allowance of plastic accessories, according to the tolerance zone method to calculate, for large precision plastic parts, as far as possible USES the analogy method, the measured plastic accessories geometry according to the different direction of shrinkage rate calculation, to make up for in theory is difficult to consider the factors.
c, the design of injection mould should be easy to manufacture. Design of injection molding, try to make injection molding design simple, low cost. Especially for those who are more complex in we need to consider is to adopt the general mechanical machining methods, or the use of special machining methods. After the use of special processing methods, processing how to assemble, the same problem need to consider and solve in injection mold design, considering the mold after the mold at the same time, must have enough mold allowance.
d, design, injection molding of high efficiency, safe and reliable. That involves many aspects of injection molding design, such as injection molding systems need to recharge, closed modules, wen rong west effect is good, demoulding mechanism is flexible and reliable.
e, injection molded parts must wear resistance. Durability of molded parts will affect the whole service life of the injection molded parts, so in the design of this kind of parts, in addition to materials, processing method, heat treatment and put forward the necessary requirements, such as push rod sales column is easy to get stuck, bending, broken, most of the fault of injection molding. Therefore, we should also consider how convenient adjustment and change, but we should pay attention to the service life of parts and the suitability of the injection mould.
f, injection structure should be adapted to the plastic molding characteristics. In the design of injection mold, must fully understand the use of plastic molding characteristics, try to meet the requirements. It is also important measures to obtain high quality plastic accessories.