Problems & solutions of PET bottle molding process, Part 1.

18, PET bottles are not straight with the central core

A, Causes:

   1, Too-early air supply

   2, Too high air pressure

   3, The stretch rod is not straight with the mold bottom

   4, Preforms quality problem

   5, Stretch rod is too slow on going down

   6, Stretch rod is too high from the mold bottom

   7, Temperature for the bottom part is too high.

B, Solutions:

   1, Slow down the delay-blow time

   2, Reduce the air pressure

   3, Fix the stretch rod position, around 1-1.5cm to the bottom.

   4, Get good quality preforms

   5, Adjust the pressure on the stretch cylinder

   6, Reduce the temperature for the bottom part of the bottles

   7, Fix the stretch rod to be in the center.