Solutions for PET bottle blow molding problems, Part three.

20, PET bottles’ thickness is not even

A, Causes:

   1, The preforms core is not straight

   2, Heating temperature is not even for all parts on the preform

   3, Air extraction on the molds is not good

B, Solutions:

   1, Fix the injection molds for the PET preforms

   2, Get good quality preforms

   3, Fix the heating tunnel, make sure all heating lamps are in the right position

   4, Reduce the heating temperature for the thickness-not-even part

   5, Increase the molds air extraction

21, PET bottles’ bottom volcano shape

A, Causes:

   1, The heating temperature for the bottom part is too low

   2, The heating temperature for the other parts is too high

B, Solutions:

   1, Make the blowing time to be a little earlier

   2, Increase the heating temperature for the bottom part

   3, Reduce the heating temperature for the other parts of the preform.