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Selection of the model surface

Select the model surface to consider the criteria:
1. The quality of plastic parts is considered to ensure the dimensional accuracy of plastic parts.
A. The part of the coaxiality request should be formed in the male mold. If it is formed in the male and female molds, it will be difficult to guarantee the coaxiality due to the incorrect mold clamping.
B. When selecting the parting surface, the difference between the size of the end of the plastic part due to the draft angle should be reduced. If the mold cavity is set in the male mold, the size difference of the plastic part will be too large due to the draft angle. When the plastic parts are not allowed to have a large draft angle, this configuration makes the demoulding difficult. If the appearance of the plastic parts is not severely requested, the parting mold can be selected in the middle of the plastic part, which can take a smaller drafting angle. Degree is favorable for demoulding
Ensure the appearance of the plastic parts: the parting surface can make a request for the part that does not affect the appearance of the plastic part and the appearance of the plastic part
2. Injector skill specifications:
A. The clamping force is considered: the projection area of the plastic part on the parting surface can be increased. When the projected area of the plastic part on the parting surface is close to the maximum injection area of the injection machine, there is a possibility of flashing. The size of the parting surface of the mold should be able to ensure that the material is not overflowing. Add the parting surface contact area to increase the contact pressure of the parting surface, avoid flashing, and simplify the processing of the parting surface
B. Template spacing: The parting surface is guaranteed to ensure the shortest male and female mold opening strokes
3. Mold construction considerations
A. Try to simplify the demold parts
a. In order to facilitate the demoulding of the plastic parts, the plastic parts should be kept in the male mold when the mold is opened. Only the joint force of the plastic parts and the male mold is greater than the joint force of the plastic parts and the female mold. There is a positive joint force between the good-looking and the female mold, and the joint force between the plastic part and the mold is not placed in the male mold.
b. When the shape of the plastic part is simple, but there are more holes or holes in the inner shape, the plastic part must be left on the mold core after molding. At this time, the mold cavity can be set on the mother mold, and the push plate can be used after the mold is opened. Topping out the plastic parts, if the mold cavity is placed on the male mold, it makes the demoulding difficult
c. When there is a metal insert, because the insert does not compress the tight mold, the mold cavity should be set in the male mold, and the electromagnetic flowmeter will remain in the female mold after the mold is opened, making the demoulding difficult.
d. If the mold core of the plastic part is symmetrically dispersed, the plastic part should be forced to remain on the male mold, and the top tube is demolded.
e. If the plastic parts have side holes, the mold core should be placed in the male mold part to avoid the mother mold core pulling, otherwise it will be difficult to form the mold.
B. Side core pulling machine
a. The side core pulling mechanism should be avoided as much as possible. If the side core is not avoided, the core should be as short as possible.
b. Because the locking force is small when the inclined slider is closed, for the large plastic parts with large projection area, the parting surface with large projection area of the plastic part can be placed on the main solid of the male and female mold clamping, and The parting surface with a smaller projected area is used as the lateral parting surface, otherwise the locking mechanism of the inclined slider must be made very large, or the overflow is caused by the lock
C. Arrangement of inconvenient pouring system: the parting surface does not hinder the normal opening of the pouring system
D. Easy to vent: In order to facilitate the discharge of gas, the parting surface can overlap with the end of the stream.
E. Facilitate the placement of the insert: when the parting surface is opened, there must be a positive space to install the insert
F. The overall structure of the mold is simplified, try to increase the number of parting surfaces, and try to take a straight split surface. The electromagnetic flowmeter should also consider whether the mold can be easily processed to facilitate the removal of the finished product, and the parting surface should be selected as far as possible on the ridgeline of the product.
4. Difficulty in mold making: It can ensure easy machining of the mold, device positioning and guiding system

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