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Causes of the crystal point of the galvanized sheet surface protective film
- Dec 14, 2018 -

The crystal point directly affects the appearance of the protective film on the surface of the galvanized sheet, and bumps are formed after laminating other substrates. Even the first-grade resin material produces crystal spots, and excessive heating in the production process or retention of the molten material produces crystal spots. In the production process, inferior raw material particles or high molecular weight (crosslinking) will form crystal points.


In general, the reasons for the crystal point of the galvanized sheet surface protective film mainly include the following:


First of all, in the production process of galvanized sheet surface protective film should pay attention to ensure the cleanliness of raw materials, including the cleanliness of the raw materials themselves and the dust pollution of the environment;

Secondly, when selecting raw materials, it should be reasonably selected. Otherwise, if there is a large difference between the raw materials, or if the raw materials are not compatible, crystal spots will occur easily;

The third is to ensure suitable processing conditions, which mainly refers to the processing temperature, etc., so as not to cause poor plasticization or over-plasticization of the raw materials, otherwise it will cause the crystal point phenomenon of the surface protective film of the galvanized sheet.

In addition, the processing capacity of the equipment should be taken into consideration, as the equipment used and the associated accessories have a very important influence on the production of the crystal dots.