Resin drying
Dry before restart after purge.
Resin dryingGlossary
What Is Purging? Injection Molding Explained
Purging removes leftover resin from the injection unit when color or material changes.
Glossary
Purging clears residual resin from the barrel when changing color or material
Dark to light changes need disciplined purge sequences to avoid streaks in early shots.
Purge compound displaces old resin from the screw and nozzle before production restarts.
Buyers see purge results as color consistency on T1 samples, not the purge slug itself.
Material change windows belong in production planning when scheduling color runs.
Production
When purge discipline matters most
Plan press time for purges on sensitive color programs.
- Black to natural or white color changes
- Switching from high temperature to lower temperature resin
- Removing degraded material after extended downtime
Go deeper
Where this term connects
Each link is a different angle on the same program, not a duplicate definition.
Hot runner
Manifold purge adds complexity.
Hot runnerT1 samples
First shots after purge show color stability.
T1 samplesPlastic molding
Production scheduling context.
Plastic moldingVisual reference
Photos from molding and tooling programs
Images are selected from the NetProto Forge media library for this topic.
Injection molded production parts on a tray
Injection molded production parts on a tray
Engineer reviewing a molded part drawing
Engineer reviewing a molded part drawing
Plastic housing components from a steel tool
Plastic housing components from a steel tool
FAQ
Purging questions
Is purging visible on the part?
Only if contamination remains and shows as streaks or specks.
Who pays for purge material?
Production quotes absorb scrap planning differently. Clarify on RFQ.
Can purging skip drying setup?
No. Hygroscopic grades still need dryers after material change.
Next step
Note color change risk
Upload CAD and color spec when light colors follow dark production.