The selection of parting surface is the key to the design of various mold structures. Whether the parting surface is selected reasonably or not is directly related to the product quality, the convenience of mold loading and unloading, and the cost of mold processing.

The requirements for parting surface selection are as follows.

1. The selection of parting surface should not affect the appearance quality of the product. The parting surface should be the non-working surface of the work-in-process, so that the flash on the parting surface is easy to remove.

2. The parting surface should make it easy to vent the rubber material without leaving air. Since the pouring PU is liquid, the dead corners in the mold are easy to trap air. Only by designing the parting surface reasonably can the air trapped in the cavity be eliminated and the rate of quality goods can be improved.

3. The parting surface should be as simple as possible and should not hinder the demolding of the rubber parts.

4. The selection of parting surface should take into account the ease of mold disassembly and assembly.

5. The selection of the parting surface should try to avoid the sharp edge, so that it is not easy to damage and wear the mold.

6. The selection of the parting surface should consider the ratio of the pressure-bearing area of the mold to the height, and try not to be too high to ensure that the mold has good thermal conductivity and uniform temperature.

7. The selection of the parting surface should consider the accuracy of the product. For the mold cavities with high concentricity requirements, they should be processed on the same template as much as possible, so that the mold manufacturing is easy and the accuracy is easy to guarantee.