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Due to the diverse market demand for molds and mold products, we have encountered many problems and difficulties in the production process of molds and products. There has been a qualitative change from the accumulation of traditional experience to the application of software development, and how to effectively control the geometric dimensions of injection moldings and products is very intuitive. Today, we will introduce it to you from the following aspects.
Firstly, it is necessary to fully understand the technical requirements of the user in many aspects, fully consider the shrinkage, flow mark, ejector angle, weld line and cracking of the injection molding products, whether the parting surface selection is appropriate, the mold processing of the formed parts, the appearance of the formed parts, and the deburring, etc. The push method is suitable, whether to use push rod, ejector plate, pushing sleeve or other methods. Whether the position of the push rod and ejector plate is appropriate, whether the side core pulling mechanism is suitable, flexible and reliable, there should be no jamming.
It is necessary to try to meet the original intention of the design in production, and find out more effective, more economical and more reasonable technological means in actual processing. Choose economical and practical machine tools and equipment, and prepare adequately in production, use tool reasonably, prevent deformation of product parts, fluctuation of product part shrinkage rate, prevent product part from demolding and deformation, improve the manufacturing accuracy of injection moldings, reduce errors and prevent the accuracy of the mold from changing can also consider suitable fixture.
Geometric size fluctuation after plastic molding is a common problem. The control of temperature in injection moldings is more complicated. Different shapes, sizes and wall thickness ratios of different molded parts have certain requirements for the cooling system. It is generally easy to control the plastic material within the optimal flow value range. Therefore, the mold should be kept at the allowed low temperature as much as possible to improve production efficiency and shorten injection cycle.
When debugging the injection moldings, the matching of appropriate injection pressure and clamping force should be determined, and the air in the gap formed by the cavity and the core and the gas generated by the plastic must be discharged from the exhaust slot. As long as there is no burr, the depth of the exhaust shoulder should be as deep as possible, and a large-sized exhaust slot should be opened behind the shoulder to allow the gas passing through the shoulder to be quickly discharged from the mold. If there are special needs, an exhaust slot should be opened on the top rod for the same reason. Due to the different shapes and sizes of some plastic parts, deformation and warping may occur under different conditions after demolding due to changes in temperature and pressure loss.
