Production, characteristics and performance of heat shrinkable film
DATE：2021/8/5 8:49:57 / READ： / SOURCE：This station
Production, characteristics and performance of heat shrinkable film
For PVC, it can also be produced by calendering and solvent casting. The film thickness is uniform, but due to the production equipment
The investment is large, the production cost is high, and it is rarely used. Shrink film is made by stretching a polymer sheet or tube at a temperature above the softening point to make the polymer chains oriented, and then fixing this orientation by cooling. When used, as long as the film is packaged and heated to the temperature at the time of stretching, the film will shrink and release the stress and energy stored during stretching. The shrinkage of the film is determined by the degree of stretching during the orientation process, and is also related to the composition of the polymer and the process conditions during production. The total shrinkage of the shrink film can reach 15% to 80%, while it only needs 15% to 30% for general use. The odd-shaped product requires a shrinkage rate of more than 50%. Generally, a shrink film with a balanced shrinkage rate in the vertical and horizontal directions is required. As far as the packaging and shrink label film of tubular goods are concerned, only unidirectional shrinkage is required.www.handern.com
The shrinkage temperature is generally between 655 to 176.6C (150T to 350), depending on the type of film, such as: PVCThe shrinkage temperature of the shrink film is 65.5～1488℃ (150T～300), and the shrinkage temperature of PP is 1655(330F)
Some heat-shrinkable films have good temperature tolerance and can be heated multiple times to obtain packages with different shrinkage rates. In principle, use the minimum heat and time to get sufficient shrinkage www.handern.com
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