Depending on the type of material to be injection molded, mold makers must take the material's process-induced shrinkage into consideration when producing the mold. In practice, they normally scale up the cavity size based on the material’s nominal shrinkage. This scaling factor is called mold shrinkage allowance. The scaled-up model is often used for the injection molding simulation to check the final part shape after shrinkage and warpage relative to the designed part dimensions and tolerances.
Select Cavity dimensions include mold shrinkage allowance. Adjust constraint positions automatically if you want to compare the deflected shape of an unconstrained part whose dimensions already include mold shrinkage allowance, to the designed part shape, or if you want the warp analysis to adjust warp constraint positions according to the mold shrinkage allowance. These warp constraints typically represent fixing or assembly locations and will be moved to match the part design dimensions, even though assigned to nodes in the scaled-up cavity dimensions.
Note: If you choose to use this feature, you should scale up the cavity dimensions in the injection molding simulation so that they represent the actual mold cavity dimensions rather than the designed part dimensions and specify this scaling-up factor as the mold shrinkage allowance.