Performance requirements and development direction

2022-07-27
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Performance requirements and development direction of precision injection molding machine

with the expansion of the application range of high-precision plastic parts and the reduction of the manufacturing cost of injection molding machine, the fully automatic injection molding machine has a lot of development space. As an injection molding machine integrating the advantages of hydraulic high performance and all electric energy saving, electric/hydraulic injection molding machine has become the development direction of precision injection molding machine

however, it is worth noting that the annual sales of domestic injection molding machines are less than the total sales of imported injection molding machines, especially in the information industry and other high-tech products. Domestic injection molding machines and imported injection molding machines are mainly used in automobile manufacturing, electronic and electrical, household appliances, sports equipment and other fields requiring high strength, high modulus, low specific gravity, anti-static, wear-resistant and other fields. The benefit difference caused by technical differences is very huge

China is the largest information industry market in the world at present, but more than 90% of the plastic parts of the body are produced by foreign injection molding machines. Therefore, in this market, if domestic injection molding machine manufacturers can catch up with each other in terms of equipment, process and technology, there should be a lot of room for development

performance requirements: the basis for judging precision injection molding is the accuracy of finished products, that is, the dimensional tolerance, geometric tolerance and surface roughness of finished products. There must be many related conditions for precision injection molding, and the most basic four basic factors are plastic material, mold, injection molding process and injection molding equipment. When designing plastic products, plastic materials should be selected first, and those materials with high mechanical properties, stable size, good creep resistance and environmental stress cracking resistance must be used for plastics that can be accurately injected. Secondly, the applicable injection molding machine should be selected according to the selected plastic materials, dimensional accuracy, weight, quality requirements of finished products and the predetermined mold structure. In the processing process, we should pay particular attention to the accuracy of the mold, injection shrinkage, and the range of environmental temperature and humidity changes of the product

precision injection molding requires stable size

in precision injection molding, the mold is one of the keys to obtain precision plastic products that meet the quality requirements. The mold used for precision injection molding should actually meet the requirements of product size, precision and shape. However, even if the precision and size of the mold are consistent, the actual size of the molded plastic products is inconsistent due to the difference in shrinkage. Therefore, it is very important to effectively control the shrinkage of plastic products in precision injection molding technology

mold is the key factor of precision injection molding

whether the mold design is reasonable or not will directly affect the shrinkage rate of plastic products. Since the mold cavity size is obtained from the size of plastic products plus the estimated shrinkage rate, it is not only related to the gate form, gate position and distribution of the mold, but also related to the crystal orientation (anisotropy) of engineering plastics, the shape, size of plastic products, and the distance and position to the gate. The main factors affecting the shrinkage of plastics are thermal shrinkage, phase transformation shrinkage, orientation shrinkage, compression shrinkage and elastic recovery, which are related to the molding conditions or operating conditions of precision injection molded products. Therefore, when designing the mold, we must consider the relationship between these influencing factors and injection conditions and the requirements of the appearance image, such as injection pressure and mold cavity pressure and filling speed, injection melt temperature and mold temperature, mold structure and gate form and distribution, as well as the influence of gate cross-sectional area, product wall thickness, content of reinforcing filler in plastic materials, crystallinity and orientation of plastic materials. The influence of the above factors is also different due to different plastic materials, other molding conditions such as temperature, humidity, continuous crystallization, internal stress after molding, and the performance of the injection molding machine

because the injection molding process is a process that transforms plastics from solid (powder or granular) to liquid (melt) and then to solid (product). From pellets to melts, and from melts to products, there are temperature fields, stress fields, flow fields and density fields. Under the combined action of these fields, different plastics (thermosetting or thermoplastic, crystalline or non crystalline, reinforced or non reinforced, etc.) have different polymer structure morphology and rheological properties. All factors affecting the above "field" will certainly affect the physical and mechanical properties, size, shape, accuracy, appearance and quality of plastic products

in this way, the internal relationship between process factors and polymer properties, structural morphology and plastic products will be shown through plastic products. It is very important to analyze the internal relations between real-time mapping and maintaining the completed experimental load waveform, so as to reasonably arrange the injection molding machine and other processing equipment. There are also differences in injection pressure and injection rate between precision injection and ordinary injection. Precision injection usually adopts high-pressure precision or ultra-high pressure injection and high-speed injection to obtain small molding shrinkage. Based on the above reasons, in addition to the design elements of general molds, the following points must be considered in the design of precision injection molds:

1. Adopt appropriate mold dimensional tolerance

2. Prevent forming shrinkage error

3. Prevent injection molding deformation

4. Prevent demoulding deformation

5. Reduce the mold manufacturing error to the minimum that graphene is highly sought after nowadays

6. Prevent the error of die precision

7. Maintain mold accuracy

Zhenxiong takes the lead

in China, the high-precision all electric injection molding machine is still in its infancy. At present, only one or two enterprises can officially produce in batch. The key to this problem is that most of the core technologies are in the hands of foreign manufacturers, and many major accessories need to be imported. In these aspects, Zhenxiong group has established long-term contacts with relevant foreign enterprises and established information and technology exchange channels, so it can grasp the advantages of advanced technology early and gain a commanding height in the highly competitive market

Zhenxiong's jetba C series precision injection molding machine

and Zhenxiong has gradually improved its transformation and upgrading in improving stability, efficiency and energy saving, hoping to surpass the foreign process level. (end)

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