Why short shot occurs and how to eliminate this problem?

A short shot is a molded part that is incomplete because insufficient material was injected into the mold. The reasons are entrapped air, insufficient machine injection pressure, insufficient injection speed, presence of oils or mold preservatives in the mold cavities, pre-mature solidification of the polymer melt, and machine defects.

Remedies to eliminate short shot problem is increasing the injection pressure, injection speed, injection volume and the mold wall temperature.