تفريغ تشكيل لفة ورقة بلاستيكية شفافة

تفريغ تشكيل لفة ورقة بلاستيكية شفافة is mainly used for food packaging, such as: disposable lunch boxes, fruit and vegetable trays,
moon cake trays, food trays and so on.
The crystallization of PP (polypropylene) is the main cause of opacity.
Using the crystallization tendency of rapidly frozen PP, a transparent film can be obtained, but for products with a certain wall thickness,
due to the time required for heat conduction, the core layer cannot be quickly cooled and frozen.
Therefore, for products with a certain thickness, the rapid cooling cannot be expected to improve the transparency.
It must start from the crystallization law of PP and the influencing factors.