How to control shrinkage and warpage during the injection molding of industrial plastic parts?
Publish Time: 2025-02-19
Injection molding is a widely used technology in the production of industrial plastic parts. However, shrinkage and warpage problems often occur during the injection molding process, which not only affect the dimensional accuracy and appearance quality of the product, but may also reduce its mechanical properties and functional reliability. Therefore, effective control of shrinkage and warpage is a key task in the injection molding process.Shrinkage refers to the dimensional change caused by the shrinkage of the molecular chain inside the material during the cooling and solidification process of the plastic part. In order to control the shrinkage, it is necessary to start from multiple aspects. First, choosing the right plastic material is the basis. The shrinkage characteristics of different materials are different, so in the product design stage, plastic materials with lower shrinkage should be selected according to the use environment and performance requirements of the parts.Secondly, mold design is also crucial. Optimizing the mold structure, such as adding a cooling system and reasonably designing the cooling channel, can increase the cooling speed and solidification time of the plastic, thereby reducing the shrinkage. At the same time, the temperature control of the mold also needs to be precise to ensure that the plastic is evenly heated and cooled during the injection molding process to avoid excessive local shrinkage.In addition, the adjustment of injection molding process parameters is also an effective means to control shrinkage. By adjusting parameters such as injection speed, pressure and temperature, the fluidity and filling of plastic can be controlled, thereby affecting the shrinkage. In actual production, it is usually necessary to go through multiple mold trials and tests to gradually optimize the process parameters to achieve the best shrinkage control effect.Warping is another common problem in injection molding. It is mainly caused by the deformation of plastic parts due to uneven internal stress distribution during the cooling process. In order to prevent warping, in addition to the mold design and process parameter adjustment mentioned above, the following points should be noted: First, ensure that the cooling system of the mold is uniform and effective to avoid temperature difference stress in the cooling process of the parts; second, optimize the structural design of the parts, such as adding reinforcing ribs, adjusting wall thickness, etc., to improve the rigidity and deformation resistance of the parts; third, use multi-point gates or hot runner technology to improve the flow state of plastic in the mold cavity and reduce the generation of internal stress.In summary, controlling the shrinkage and warpage during the injection molding process of industrial plastic parts requires comprehensive consideration from multiple aspects such as material selection, mold design, process parameter adjustment and component structure design. Through continuous optimization and improvement, the quality and performance of injection molded products can be effectively improved.
