Troubleshooting

Weld line defects

Possible causes: ? Air trapping (burning is the extreme) ? Venting inadequate ? Venting inadequate in ribs ? Fill pattern causing backfilling or flow front freezing and restarting

Discoloration

Possible Cuases: ? Overdrying ? Long melt residence time ? Contamination

Flashing

Possible causes: Poor mold spot Injection pressures is too high Insufficient clamp tonnage

Flowlines

Possible Causes: ? Gate and runner design ? Temperature differences in the incoming material/flow path ? Shear differences in the flow path Part wall thickness/ gate location/ or fill pattern causing flow stoppage or hesitations

Gate blush

Possible Causes: ? Gate design ? Fast injection speed

Sinks and voids

Possible Cauces: ? Melt temperature too low ? Injection speed too fast ? Hot spots in mold Insufficient packing

Air splay & decompression splay

Possible Causes: ? Trapped air in nozzle/tool (foamy tail on bubbles)/Trapped air on screws

Moisture Streak

Possible Causes: ? Improperly dried material (the material is extremely wet.)?

Warpage

Possible Causes: ? Mold surface too hot Underpacking

Sink Mark

Possible Causes: ? Injection speed too fast ? Melt temperature too low ? Insufficient packing