The first principle of injection mold parting surface design is to ensure that the plastic product can be demolded smoothly. The parting surface should be selected at the maximum contour of the product shape, so that the product can be completely removed from the mold cavity when the mold is opened and closed. For example, for box-shaped plastic products with regular shapes, the parting surface is usually set at the maximum cross-section of the box body. At the same time, the selection of the parting surface needs to consider the demolding slope of the product to ensure that the product will not be deformed or damaged due to excessive demolding resistance during the mold opening process. In addition, for products with complex structures such as side holes and side recesses, lateral parting or core pulling mechanisms can be used to assist demolding. At this time, the design of the parting surface should be coordinated with the core pulling direction to ensure that the movements of each component are coordinated and the product can be demolded smoothly.
The design of the injection mold parting surface directly affects the appearance quality of plastic products. The parting surface should be avoided on important surfaces of the product appearance, such as high-gloss surfaces and decorative surfaces, to prevent the parting line marks from being left on the surface of the product and affecting the appearance. If it cannot be avoided, the parting line can be hidden in non-critical parts of the product, such as edges, bottoms or inconspicuous transition areas, by optimizing the shape and position of the parting surface. At the same time, when designing the parting surface, the location and direction of the weld mark should be considered. Reasonable parting surface design can guide the flow of molten material, reduce the appearance of weld marks or distribute them in a position that does not affect the strength and appearance of the product. For example, when using multiple gates for feeding, the setting of the parting surface should be coordinated with the gate position so that the molten material can evenly converge in the cavity and reduce the adverse effects of weld marks.
Simplifying the mold structure is one of the important principles of parting surface design. The simpler the shape of the injection molds parting surface, the lower the processing difficulty and manufacturing cost of the mold, and it is also convenient for mold assembly and debugging. Try to use straight parting surfaces and avoid complex curved parting surfaces to reduce milling, EDM and other processes during mold processing. For some products with complex shapes, if a single parting surface cannot meet the demoulding requirements, you can consider using a combined parting surface, but make sure that the combination method is reasonable to avoid adding too many mold parts and complex assembly processes. In addition, the simplified mold structure is also reflected in the design of the parting surface to facilitate the layout of the mold's exhaust and cooling system, and reduce the problems of poor exhaust and uneven cooling caused by complex structures.
The design of the injection molds parting surface must fully consider the mold processing and manufacturing process. When selecting the parting surface, it is necessary to ensure that the mold cavity and core are easy to process, and minimize the parts that are difficult to process. For example, for deep-cavity products, if a vertical parting surface is used, the core may be too high and the processing difficulty will increase. At this time, consider using a horizontal parting surface or a stepped parting surface to reduce the processing difficulty. At the same time, the design of the parting surface should facilitate the measurement and detection of the mold to ensure the dimensional accuracy of the mold. The reasonable position of the parting surface should enable the key dimensions of the mold to be easily measured and controlled during the processing process to avoid dimensional errors caused by measurement difficulties. In addition, the design of the parting surface must also consider the utilization rate of the mold material, reduce waste generation, and reduce production costs.
The design of the injection molds parting surface has an important influence on the dimensional accuracy of plastic products. The position and shape of the parting surface should ensure that the dimensional accuracy of the cavity can be effectively controlled when the mold is closed. When designing the parting surface, the clamping force distribution of the mold should be considered to avoid flash and deformation of the product during the molding process due to uneven clamping force, which will affect the dimensional accuracy. For products with high dimensional accuracy requirements, precision parting surface design can be adopted, such as using conical surface positioning, inclined surface positioning and other structures to improve the mold clamping accuracy and stability of the mold. At the same time, the surface roughness of the parting surface must also be strictly controlled to avoid product dimensional deviation due to surface unevenness. By reasonably designing the parting surface and coordinating with precise mold processing and assembly processes, the dimensional accuracy of the product can be effectively guaranteed.
On the basis of meeting the basic design principles, some innovative techniques can be used to improve the effect of parting surface design. For example, by adopting asymmetric parting surface design, for some products with asymmetric shapes, by reasonably setting asymmetric parting surfaces, the melt flow path can be optimized and the deformation and warping of the product can be reduced. For another example, using variable parting surface technology, the position or shape of the parting surface can be adjusted as needed during the opening and closing of the mold. This design is suitable for some products with special demolding requirements, such as products with movable parts or products that need to be demolded in steps. In addition, the parting surface can be combined with the exhaust system and cooling system of the mold for innovative design. For example, an exhaust groove or cooling channel is opened on the parting surface, which not only meets the exhaust and cooling needs, but also simplifies the mold structure and improves production efficiency.
With the development of digital technology, the introduction of computer-aided design (CAD) and computer-aided engineering (CAE) technology in the design of injection molds parting surface has become an important means of innovation. Through CAD software, designers can quickly create and modify parting surface models, intuitively display the shape and position of the parting surface, and facilitate design optimization. Using CAE technology to simulate and analyze the injection molding process, the molding quality of the product under different parting surface design schemes can be predicted in advance, such as filling conditions, weld mark distribution, deformation trend, etc. According to the simulation results, the designer can adjust the parting surface design in time, optimize the mold structure, and avoid the increase in the number of mold trials and the increase in production costs due to unreasonable design. The application of digital design and simulation optimization technology makes the injection molds parting surface design more scientific and efficient, providing strong support for innovative design.
