Defect

Remdedies

Weld lines

1. Increase injection pressure

2. Increasement temperature or nozzle temperature

3. Increase sprue cross-sections or change it’s position

4. Optimize mold venting

Fractures

1. Melt temperature is too low or too high

2. Reduce the proportion of recycled materials

3. Check material drying

4. Increase spruecross-sections

Black (overheating) marks

1. Reducemelt temperature

2.Reduce the proportion of recycled materials

3. Optimize mold venting, check venting channels

4. Cleanscrew, nozzle, barrel

Flash

1. Reduce injection pressure

2. Reduce melt temperature

3. Increase clamping force

4. Adjust the defect of mold

Hollows

1. Increase holding pressure

2. Extend holding pressure time

3. Check the check value

4. Optimize mold venting

5. Reduce mold temperature or reduce injection speed

Screw slip

1. Reduce screw feed temperature

2. Add recycle material

3. Reduce barrel temperature

4. Check defect of screw feed section

5. Check if diffusion oil excessive

Bubbles

1. Material too moist，fully dry the material

2. Optimize mold

3. Holding pressure not sufficiently effective, increase holding pressure

4. Reduce barrel temperature

Streaks

1. Increase sprue cross-sections and temperature

2. Check drying process (fully dry)

3. Reduce injection speed and injection temperature

4. Optimize mold cavity

Warpage

1. Reduce mold temperature

2. Increase holding pressure

3. optimizing gate position

4. Reduce injection speed

5. Increaseholding pressure time

Poor demolding behavior

1. Reduce injection pressure

2. Reduceholding pressure time

3. Add release agent

4. Optimize mold defect

5. Optimize sprue position and cross-sections

6. Increase the Draft angle of mold