Page 248 - Injection Molding Advanced Troubleshooting Guide

26 Dimensions

„ „26.1„ Description

One of the biggest ongoing potential problems in molding is dimensional control.
Plastic will tend to grow and shrink based on environmental conditions. Variations
during the processing of plastic will also lead to dimensional variation. Any given
part may end up too large or too small or even have one dimension that is accept-
able and another that is unacceptable.

Also known as: too big, too small, inconsistent, shrink
Mistaken identity: warp

„ „26.2„ Dimensions Troubleshooting Chart

Table 26.1 shows the dimensions troubleshooting chart.

Table 26.1 Dimensions Troubleshooting Chart
Molding Process Mold Machine Material
second-stage pressure gate size nozzle tip filler
second-stage time sprue and runner size velocity to pressure nucleating agents
transfer
fill velocity cooling non-return valve type
fill only weight hot runner control machine performance
melt temperature component deflection
mold temperature
cooling time
decompression
cushion