Page 335 - Injection Molding Advanced Troubleshooting Guide

34 Jetting

„ „34.1„ Description

Jetting is a defect where the plastic entering does not form a consistent flow front
but rather blasts into the mold in a stream. The stream of plastic will travel across
the cavity until the melt stream hits something, at which point the incoming plas-
tic will fill around the jetting. See Figure 34.1 and Figure 34.2 for examples of jet-
ting. Be aware that jetting can produce surface defects that show as blush or splay.

Also known as: worm tracks
Mistaken identities: splay, blush

Figure 34.1 Example of jetting defect