Shrink & Flash
With most injection molding resin a certain degree of shrink can be expected due to the materials chosen. Some materials tend to shrink more than others so careful consideration on material choice should be made.
Rapid changes to wall thickness are the most common cause of shrinkage due to the pressures exerted for the plastic material to fill your mold. When designing your parts try to minimize thin wall sections leading into thicker wall sections and create parts with uniform wall thickness throughout.
If thick and thin sections are neccessary try to transistion the change gradually, utilizing angles to help aid the flow of materials throughout your plastic parts.
Controlling part shrinkage is critically important especially in tight tolerance plastic parts.
Flash of an injection molded part can happen for several reasons - slight variations in the material, pressure, speed, injection mold process and/or problems with the tooling itself.
Injection Mold Shrink Flash occurs on a parts edge around the parting line or any place where two mold components meet.
At Xcentric our process engines allow us to produce your parts to very tight tolerances by analyzing every step of the injection molding process and ensuring consistent stress free manufacturing of your custom plastic parts.