Product Issues and Solutions During Injection Mold Testing
1. Main Runner Adhesion
① Polish the main runner → ② Align the nozzle with the mold center → ③ Reduce the mold temperature → ④ Shorten the injection time → ⑤ Increase the cooling time → ⑥ Check the nozzle heating ring → ⑦ Polish the mold surface → ⑧ Inspect for plastic resin contamination.
2. Difficult Mold Release for Plastic Parts
① Reduce injection pressure → ② Shorten injection time → ③ Increase cooling time → ④ Lower mold temperature → ⑤ Polish the mold surface → ⑥ Increase the draft angle for demolding → ⑦ Reduce clearance at the insert locations.
3. Poor Dimensional Stability
① Change barrel temperature → ② Increase injection time → ③ Raise injection pressure → ④ Adjust screw back pressure → ⑤ Raise mold temperature → ⑥ Lower mold temperature → ⑦ Regulate material feed rate → ⑧ Decrease the use of recycle plastic.
4. Surface Ripples
① Adjust material feed rate → ② Raise mold temperature → ③ Increase injection time → ④ Increase injection pressure → ⑤ Raise material temperature → ⑥ Increase injection speed → ⑦ Increase the size of the runner and gate.
5. Warping and Deformation of Plastic Parts
① Reduce mold temperature → ② Lower material temperature → ③ Increase cooling time → ④ Decrease injection speed → ⑤ Reduce injection pressure → ⑥ Increase screw back pressure → ⑦ Shorten injection time.
6. Peeling and Layering of Plastic Parts
① Check the type and grade of plastic → ② Inspect for plastic contamination → ③ Increase mold temperature → ④ Perform material drying → ⑤ Raise material temperature → ⑥ Decrease injection speed → ⑦ Shorten the gate length → ⑧ Reduce injection pressure → ⑨ Change gate location → ⑩ Use a larger orifice nozzle.
7. Silver Streaks
① Reduce material temperature → ② Perform material drying → ③ Increase injection pressure → ④ Increase gate size → ⑤ Check the type and grade of plastic → ⑥ Inspect for material contamination.
8. Poor Surface Gloss
① Perform material drying → ② Check for material contamination → ③ Increase material temperature → ④ Increase injection pressure → ⑤ Raise plastic mold temperature → ⑥ Polish the mold surface → ⑦ Increase the size of the runner and gate.
9. Shrinkage
① Adjust material feed rate → ② Increase holding pressure → ③ Extend holding time → ④ Decrease injection speed → ⑤ Lower mold temperature → ⑥ Increase venting holes → ⑦ Enlarge runner and gate dimensions → ⑧ Shorten runner length → ⑨ Change gate location → ⑩ Increase injection pressure → ⑪ Increase screw back pressure.
10. Air Bubbles
① Perform material drying → ② Reduce material temperature → ③ Increase injection pressure → ④ Extend injection time → ⑤ Raise mold temperature → ⑥ Decrease injection speed → ⑦ Increase screw back pressure.
11. Insufficient Plastic Filling
① Adjust material feed rate → ② Increase injection pressure → ③ Extend cooling time → ④ Raise mold temperature → ⑤ Increase injection speed → ⑥ Increase venting holes → ⑦ Increase runner and gate size → ⑧ Extend cooling time → ⑨ Shorten runner length → ⑩ Extend injection time → ⑪ Check for nozzle blockage.
12. Plastic Flash
① Reduce injection pressure → ② Increase clamping force → ③ Decrease injection speed → ④ Lower material temperature → ⑤ Lower mold temperature → ⑥ Recorrect parting line → ⑦ Reduce screw back pressure → ⑧ Inspect parting surface area → ⑨ Check mold flatness → ⑩ Verify that mold parting surfaces are properly locked.
13. Welding Marks
① Increase mold temperature → ② Raise material temperature → ③ Increase injection speed → ④ Raise injection pressure → ⑤ Increase venting holes → ⑥ Enlarge runner and gate size → ⑦ Reduce mold release agent usage → ⑧ Decrease the number of gates.
14. Decreased Plastic Strength
① Perform material drying → ② Lower material temperature → ③ Check for material contamination → ④ Raise mold temperature → ⑤ Reduce screw rotation speed → ⑥ Lower screw back pressure → ⑦ Increase venting holes → ⑧ Change gate location → ⑨ Decrease injection speed.
15. Cracks
① Raise mold temperature → ② Reduce cooling time → ③ Increase material temperature → ④ Extend injection time → ⑤ Increase injection pressure → ⑥ Lower screw back pressure → ⑦ Preheat inserts → ⑧ Shorten injection time.
16. Black Spots and Streaks
① Lower material temperature → ② Realign the nozzle → ③ Reduce screw rotation speed → ④ Lower screw back pressure → ⑤ Use a larger orifice nozzle → ⑥ Increase venting holes → ⑦ Enlarge runner and gate size → ⑧ Reduce injection pressure → ⑨ Change gate location.