Moisture related
- Splay or silver streaks across multiple regions
- Property loss on first shots after storage
Glossary
What Is Resin Drying? Injection Molding Explained
Resin drying prepares hygroscopic and sensitive grades before they enter the injection barrel.
Glossary
Resin drying removes moisture before processing hygroscopic and sensitive grades
Undried material shows splay, bubbles, or property loss on early production shots.
Dryers at the press reduce moisture for nylon, PC, PET, and other hygroscopic families.
Processors follow supplier datasheets for temperature and time at dryness targets.
Note sensitive resins on RFQs so scheduling includes dryer capacity.
Glossary
How resin drying shows up on real programs
Library photos illustrate molding and tooling context for this term.
- Use the term in RFQs with geometry and material context, not in isolation.
- Link to the design guide when the term affects steel or part design.
- Upload CAD when the term changes tooling scope or piece price.
Symptoms
Moisture defects versus vent issues
Location and pattern on parts help triage.
Vent related
- Burn at last fill region only
- Short fill in same pocket every shot
Go deeper
Where this term connects
Each link is a different angle on the same program, not a duplicate definition.
Hygroscopic resin
Resins that absorb ambient moisture.
Hygroscopic resinVent
Trapped air versus moisture.
VentPurging
Restart after material change.
PurgingDFM article
Design with process windows.
DFM articleVisual 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
Resin drying questions
Who sets drying parameters?
Processors follow supplier datasheets unless RFQ overrides.
Can I skip drying for prototype shots?
Expect defect risk. Production assumes proper drying.
Does regrind need separate drying?
Regrind streams can carry moisture if stored open.
Next step
Flag hygroscopic resin on RFQ
Upload CAD with material family so drying is planned.