Home > Exhibition > Content
PVC film hardness will change with the temperature
Aug 18, 2017

The PVC bag made in summer will become hard and crisp in winter. On the contrary, the PVC bag made in winter will become soft and tough in summer. What is the reason?

Originally, PVC film is a kind of heat sensitive material, its soft hardness will change with the change of temperature, the temperature will become soft, and the temperature will be hard. On the premise of constant temperature, the hardness of PVC film depends on its oil content, and the higher the oil content is. This "oil" is a plasticizer in the PVC film. We often say PVC film oil 27 PA, 45 PA, etc., that is, the content of oil. For example, 100KGPVC film, if the plasticizer content is 30KG, then the corresponding oil is 30 PA (writing 30P).

The formula of PVC film is usually divided into summer formula, winter formula and spring and autumn formula according to the level of oil. In general, the PVC film 3 formulations do not use seasonal. Accordingly, 3 kinds of PVC films made of PVC bag, do not use the general season. If you take the summer or spring and winter PVC bag to use in winter, it is prone to embrittlement. On the other hand, if the bags made in winter or spring and autumn are used in summer, there will be soft and no bones. Spring and autumn do bag should not be used in the two seasons of winter and summer.

Is there any way to keep the hardness of the PVC film from being stabilized by the temperature? It is difficult to be absolutely unaffected, but we can alleviate the problem in 2 ways. One way is to make sure that the oil is not too high or too low to remain moderate, but it can be difficult to make. Another method is to add proper amount of cold resistant agent (also known as antifreeze) to the PVC film. Cold resistant agent can increase the toughness of the film, and will not crack in the low temperature environment. PVC bags used in some low temperature areas, such as Russia, usually require PVC bags to remain brittle at subzero temperatures of 15 degrees celsius.