The molding accuracy of precision injection mold directly affects the product quality. Behind it is the synergy of multiple processes. From the design source to the manufacturing process, each link is crucial to the control of accuracy.
The design process of precision injection mold is the primary link to ensure molding accuracy. In the design stage, with the help of advanced computer-aided design software, engineers can accurately model the mold structure. Through detailed analysis of the three-dimensional model of the product, the flow, filling and cooling process of the plastic melt in the mold cavity are simulated, and possible deformation, shrinkage and other problems can be predicted in advance. For example, for products with complex shapes, the gate position and runner layout will be fully considered during the design to ensure that the plastic melt fills the cavity evenly and avoid dimensional deviations caused by uneven filling. At the same time, the reasonable design of the mold parting surface and demolding mechanism can reduce the risk of deformation of the product during the demolding process and lay the foundation for high-precision molding.
The processing technology of precision injection mold plays a decisive role in molding accuracy. When manufacturing mold parts, the use of high-precision processing equipment is the key. With its high speed and high feed characteristics, CNC machining centers can perform fine cutting on mold steel and process cavities and cores with precise dimensions. EDM technology is suitable for processing mold parts with complex shapes and high precision requirements. Through discharge corrosion between the electrode and the workpiece, precise processing of tiny sizes can be achieved. In addition, post-processing processes such as grinding and polishing are also indispensable. They can further improve the surface finish and dimensional accuracy of the mold, reduce the flow resistance of the plastic melt, and make the product surface smoother and more accurate in size.
Precision injection mold material processing technology is also an important factor in ensuring accuracy. Before processing, mold steel needs to be properly heat treated, such as quenching and tempering. Quenching can improve the hardness and wear resistance of steel, while tempering can eliminate the internal stress generated by quenching and stabilize the organizational structure of steel. Mold steel that has undergone reasonable heat treatment can better withstand high temperature and high pressure during the injection molding process, and reduce mold size changes caused by material deformation. At the same time, surface treatment processes, such as hard chrome plating and nitriding, can not only improve the hardness and wear resistance of the mold surface, but also reduce the surface roughness, making it easier for the plastic melt to demold, ensuring the dimensional accuracy and surface quality of the product.
The mold assembly process has a direct impact on the molding accuracy. During the assembly process, the matching accuracy between the various components needs to be strictly controlled. For active parts such as sliders and ejectors, it is necessary to ensure that they slide smoothly and the gap is reasonable. Too large a gap will cause defects such as flash and burrs on the product, and too small a gap may cause the parts to get stuck. Through precise measuring tools and assembly technology, the various components of the mold are accurately assembled and debugged to ensure that the opening and closing of the mold is smooth and the relative positions between the components are accurate, thereby ensuring the molding accuracy of the product.
Accurate control of injection molding process parameters is the key link to ensure molding accuracy. During the injection molding process, parameters such as temperature, pressure, and time have an important influence on the molding accuracy of the product. The barrel temperature needs to be precisely controlled. Too high a temperature will cause the plastic melt to decompose and degrade its performance. Too low a temperature will cause the melt fluidity to deteriorate and the filling to be insufficient. The injection pressure and holding pressure should be reasonably adjusted according to the shape, size and mold structure of the product to ensure that the plastic melt can fully fill the cavity and maintain dimensional stability during the cooling process. The control of cooling time is also crucial. The appropriate cooling time can make the product cool evenly and avoid deformation due to uneven cooling.
The maintenance process of the mold should not be ignored. Regular cleaning, lubrication and inspection of the mold can timely discover and solve potential problems and maintain the accuracy of the precision injection mold. Cleaning the mold surface and cavity can prevent impurities, oil stains, etc. from affecting the flow of plastic melt and the molding quality of the product. Lubricating the moving parts of the mold can reduce friction and ensure the normal operation of the parts. Regularly check the dimensional accuracy and surface quality of the mold, and repair or replace it in time if wear or damage is found to ensure that the mold is always in good working condition and continuously ensure the molding accuracy of the product.
Precision injection mold strictly controls the entire process from mold manufacturing to product production through the coordinated cooperation of multiple processes such as design, processing, material processing, assembly, injection molding process parameter control and maintenance, thereby ensuring molding accuracy and producing plastic products that meet high-precision requirements.
