Trouble Shoot

Trouble Shooting


 

1. Parts Sticking

Molding Conditions Tooling Material
1. Adjust Temperature 1. Purge and wax clean all mold surfaces 1. Use shorter flow
2. Increase cure cycle

 

2. Weak Parts

Molding Conditions Tooling Material
1. Increase cure time 1. Adjust height of ejector pins for even ejection 1. Use stiffer flow
2. Increase temperature 2. Use longer glass fiber

3. Thick or Excessive Flash

Molding Conditions Tooling Material
1. Decrease injection pressure 1. Adjust for proper closure 1. Use shorter flow
2. Increase clamp pressure

4. Short Fill

Molding Conditions Tooling Material
1. Add more material 1. Repair worn screw 1. Use longer flow
2. Increase injection pressure 2. Slower cure

5. Sink Marks

Molding Conditions Tooling Material
1. Adjust temperature 1. Purge and wax clean all mold surfaces 1. Use shorter flow
2. Increase cure cycle

6. Porous Parts or Trapped Gas

Molding Conditions Tooling Material
1. Decrease injection speed 1. Enlarge gate 1. Use stiffer flow
2. Add more material 2. Add venting
3. Increase barrel temperature 3. Increase barrel temperature
4. Lower back pressure
5. Adjust molding temperature

7. Knit Lines and White Marks

Molding Conditions Tooling Material
1. Decrease molding temperature 1. Move gate position 1. Use softer flow
2. Increase injection pressure 2. Enlarge vent

8. Low Gloss

Molding Conditions Tooling Material
1. Increase temperature 1. Add vents 1. Use different flow
2. Increase cure cycle 2. Enlarge gates
3. Decrease back pressure
4. Decrease injection speed

9. Blisters

Molding Conditions Tooling Material
1. Adjust temperature 1. Polish or clean mold surfaces 1. Use softer flow
2. Increase cure cycle

10. Distorted Parts (warpage)

Molding Conditions Tooling Material
1. Adjust for even molding temperature 1. Use cooling jig 1. Use stiffer flow
2. Increase cure cycle 2. Adjust for even ejection
3. Increase injection pressure 3. Enlarge gate or runner

11. Precure in Nozzle or Barrel

Molding Conditions Tooling Material
1. Decrease barrel/nozzle temperature 1. Repair screw 1. Use different flow
2. Increase holding time 2. Reduce screw clearance or increase nozzle size 2. Use slower cure
3. Decrease back pressure 3. Enlarge runner

12. Sprue Sticking

Molding Conditions Tooling Material
1. Increase mold temperature 1. Repair nozzle 1. Add more lubricant
2. Decrease injection pressure 2. Increase nozzle taper
3. Increase cure cycle 3. Polish sprue bushing

13. Mold Staining

Molding Conditions Tooling Material
1. Adjust molding temperature 1. Increase venting 1. Use different flow
2. Decrease back pressure 2. Polish sprue bushing
3. Increase cure time

14. Screw Will Not Bottom

Molding Conditions Tooling Material
1. Adjust barrel temperature 1. Use smaller screw 1. Use different flow
2. Use less feed 2. Repair worn screw
3. Increase holding time 3. Tighten clearance