Problems & solutions of PET preforms injection process, Part 7.

16, White or milky color on preforms after adjusting the temperature

A, Causes:

   1, The temperature is too low or too high

B, Solutions:

   1, Change the temperature to a right parameter

   2, Increase the temperature

   3, Make sure the internal and external of the preforms the same

17, Holes on preforms end/bottom

A, Causes:

   1, Temperature for the end/bottom part is too high

   2, Temperature for the preforms body is too low

   3, Raw plastic granules are not good quality

B, Solutions:

   1, Adjust the temperature for the preforms

   2, Get good quality PET granules

   3, Increase the dryer, make sure the PET granules are dried enough.