Determination of the parting surface of the hottes

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Determine the parting surface of plastic injection mold (Part 2)

d) try to avoid lateral core pulling

plastic injection mold, and try to avoid using lateral core pulling, because the structure of lateral core pulling mold is complex, and it directly affects the size and matching accuracy of plastic parts, and it takes time and money, resulting in a significant increase in cost, so it can only be used under the condition of necessity

e) make the parting surface easy to process

the accuracy of the parting surface is an important part of the accuracy of the whole mold, and strive to ensure that the flatness and the parallelism of the moving and fixed mold system tube fitting surface are within the tolerance range. Therefore, the parting surface should be plane and perpendicular to the demoulding direction, so as to ensure the machining accuracy. If the parting surface is selected as an inclined plane or curved surface, it will be more difficult to process, and the accuracy cannot be guaranteed, which is easy to cause material overflow and flash

f) make the lateral core pulling as short as possible as our excellent effect

the shorter the core pulling is, the shorter the moving distance of oblique core pulling is, on the one hand, it can reduce the thickness of moving and fixed mold and reduce the dimensional error of plastic parts; On the other hand, it is conducive to demoulding. There are two vertical holes in the plastic part. We should make the hole with large depth consistent with the opening direction, and the hole with small depth placed on the side, and use the lateral core pulling method to form

g) ensure the accuracy of plastic parts

as plastic parts of mechanical parts, the requirements for parallelism, concentricity and coaxiality are very high. Ensuring the accuracy of plastic parts not only improves the accuracy of mold manufacturing, but also has a great relationship with the selection of parting surface

for a duplex gear, the big and small gears require high coaxiality. If I-I parting surface is selected, the big and small gears are placed in the moving and fixed mold respectively, and the coaxiality of the two gears is not high due to mold closing error; For example, selecting II - II resin matrix composites is mainly used for the cold end profile of aeroengine. The pinion and pinion are in the moving mold, and the clamping error of the moving and fixed mold has no effect. As long as the manufacturing error meets the requirements, the coaxiality of the pinion and pinion can be effectively guaranteed

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