Common problems and solutions for PET preforms injection molding machine, Part 2.

3, Clear/transparent PET preforms change into non-clear preforms

A, Causes:

   1, the temperature for the molds-separating is too high

B, Solutions:

   1, Enhance the cooling water

   2, Increase the cooling time

   3, Change the injection time

4, Fogy shadow appears at any side of the preform.

A, Causes:

   1, Holding pressure is too high.

   2, Bottom injection hole is not in the center.

B, Solutions:

   1, Reduce the pressure

   2, Fix the molds bottom parts.

5, Silver waves or a little-yellow-colors on the PET preforms.

A, Causes:

   1, Plastic decomposition

B, Solutions:

   1, Reduce the dryer temperature, and increase the drying time.

   2, Adjust the injection speed

   3, Reduce the material temperature

   4, Reduce the temperature on the hot nozzles.