Identify and fix 16 common injection molding defects
Cause: Insufficient holding pressure or time. Solution: Increase pack pressure, extend hold time, or reduce wall thickness at thick sections.
Cause: Melt fronts meeting at low temperature. Solution: Increase melt temperature, adjust gate location to avoid flow splits.
Cause: Uneven cooling or molecular orientation. Solution: Balance mold temperature, adjust cooling channel design.
Cause: Mold parting line wear or excessive injection pressure. Solution: Check mold condition, reduce injection speed.
Cause: Insufficient material or air traps. Solution: Increase shot size, add venting, raise melt temperature.
Cause: Trapped air igniting. Solution: Add venting, reduce injection speed.
Cause: Melt jetting through gate without contacting mold wall. Solution: Use larger gate, reduce injection speed.
Cause: Material shrinkage in thick sections. Solution: Reduce wall thickness, increase pack pressure.
| Defect | Primary Cause | Quick Fix |
|---|---|---|
| Sink Mark | Insufficient pack | Increase hold pressure |
| Weld Line | Cold melt front | Increase temp or speed |
| Warpage | Uneven cooling | Balance mold temp |
| Short Shot | Low fill | Increase shot volume |