Page 183 - Injection Molding Advanced Troubleshooting Guide

19 Buildup

„ „19.1„ Description

Buildup is an issue that can occur from outgassing of volatiles from the plastic
material being molded. Buildup will often lead to other issues such as splay be-
cause buildup in the vents reduces the ability of the mold to vent gas out of the
cavity. Sometimes buildup will occur on the cavity of the mold leading to cosmetic
defects that appear rough. Figure 19.1 shows a mold with severe buildup at the
vents: notice the staining and erosion of the cavity steel.
Also known as: plate out, gas buildup
Mistaken identities: none

Figure 19.1 Severe buildup causing steel erosion