In the process of blowing, we often find this kind of problem. The PET bottle has pearl-like luster and whitening. What is the cause and the solution?
Causes of pearl luster and whitening during PET bottle blowing:
(1) Preform heating temperature is too low
(2) The problem of uneven wall thickness of the embryo tube occurs during the injection molding process.
(3) The thickness of the embryo tube is too thick, and the heating time is insufficient to penetrate. The temperature is not reached.
1. Heat up the bottle blowing machine or slow down the revolution speed
2. Improve the quality of the embryo tube of the injection molding machine, and replace high-quality injection molds when necessary.
3. Reduce the thickness of the embryo tube, or try to increase the outer cover of the heating device to increase the surface temperature of the embryo tube. You can calculate the heating time according to the weight of the tube, and the time is strictly in accordance with the specified time.