Common Defects of PET Preforms in Hot Runner Injection Molding (2)

Common Defects of PET Preforms in Hot Runner Injection Molding (2)

Defect 3: Bottle blanks become opaque by transparency

     The cause of the defect:

                            Stripping temperature is too high

     Defects processing method:

                            1. Enhanced cooling water

                            2. Extended cooling time

                            3. Change the injection time


Defect 4: Foam on the side of the preform

     The cause of the defect:

                           1. Pressure is too high

                           2. Base film gate eccentricity

     Defects processing method:

                           1. Reduce pressure

                           2. Fix the mold


Defect 5: The preform has silver lines or yellow

     The cause of the defect:

                            Plastic decomposition

     Defects processing method:

                           1. Reduce drying temperature and extend drying time

                           2. Adjust the injection speed

                           3. Reduce material temperature

                           4. Reduce heat nozzle temperature