The processing properties that affect mold design include shrinkage rate, flowability, crystallinity, thermal sensitivity, thermal performance, and curing characteristics.

The shrinkage rate of soft elastomers largely determines the achievable performance of the product, affects the mold pouring system and the design of molded parts, and sometimes determines the injection molding process method and mold category. The fluidity of materials has many impacts on the detailed design of molds. The quality of fluidity involves the size of shear ladders at various points in the flow channel during the flow process, which affects the orientation and thus the change in shrinkage rate.

Crystallization is usually applied to thermoplastic elastomers with crystallinity. Thermosetting plastics, some thermoplastic plastics, and rubber have varying degrees of sensitivity to heat during the injection molding process. Heat here has good implications for mold design: shear heat generation and prolonged heating. The length of heating time is mainly related to the rationality of the runner designer and whether it can greatly reduce the resin's hysteresis and retention time. The melting point, crystallization temperature, and thermal deformation temperature of thermoplastics and plastic elastomers affect the design of mold cooling systems, while the curing properties of thermosetting plastics and rubber affect the design of mold heating and washing.