Shrinkage Shrinkage is the difference between the dimensions of the cooled part and the tool. Having this inherent characteristic, Capron nylon products tend to exhibit shrinkage resulting from a decrease in part volume as material crystallization occurs. Resins with higher filler content will have less shrinkage. When designing the injection mold it is important to specify the proper material shrinkage in order to achieve a part that meets your dimensional requirements. Below are several factors which may affect the shrinkage of an injection molded component.
Shrinkage is usually greater in the cross flow direction.
Part designs that contain large variations in cross section thickness can lead to unequal stresses throughout the part and tends to cause differential shrinkage to become more pronounced. Increased glass content as a filler reinforcement will tend to lower the shrinkage of the material. Random glass orientation, which can result from tool design scenarios containing multiple gates, can be effective in leading to a more uniform part shrinkage condition. Thicker areas shrink more than thinner areas. Figure 5b shows an example of the potential effects of gating on part geometry.