Various shrink films

1. Polypropylene shrink film

Advantages of polypropylene shrink film: ① transparency and gloss are equivalent to that of cellophane; ② Excellent elasticity recovery, oil resistance, and resistance to corrosion, with strong shrinkage stress. Disadvantages: low heat sealing strength, high shrinkage temperature, and narrow range. Japan is used for general commercial packaging. Used in the United States for packaging records, etc.

2. Polyvinylidene chloride

Mainly used for packaging meat products, etc. As mentioned earlier, it is commonly used for packaging ham and sausages, hence it is also known as casing film.

3. Polystyrene

Polystyrene shrink film is used for packaging lettuce, etc.

4. Polyester (PET) shrink film

PET shrink film has high transparency, high strength, good impact resistance, toughness, gloss, easy printing, and high shrinkage rate. When making shrinkage labels for PET bottles, the shrinkage rate reaches over 70%. Good dimensional stability and heat resistance, suitable for cooking sterilization at 95 ℃, cooking sterilization at 120 ℃, and high-temperature cooking sterilization at 135 ℃. The shrinkage stress is high, such as about twice that of PVC at 80 ℃ and 2-5 times that of PVC at 100 ℃. Therefore, it is suitable for requiring significant shrinkage

Power packaging, such as packaging machinery products and building material products.

5. EVA shrink film

The characteristics of EVA shrink film are high shrinkage stress, low heat sealing temperature, and a wide range of heat sealing temperatures.

The performance of EVA decreases with the increase of EVA content, resulting in a decrease in crystallinity, an increase in impact strength, an increase in transparency, a decrease in softening point, a wider melting point range, and improved heat sealing characteristics. As a shrinkage film, EVA has great development prospects. The purpose of EVA shrink film is mainly to make use of its small shrinkage force, which is suitable for packaging items that are afraid of damage to their shape, and for packaging items with an emphasis on the appearance after packaging or irregular items with protrusions. It can also be used for shrink packaging of raw meat on shallow plates, fiber products such as blankets, and polyurethane products. The heat sealing shrinkage film of EVA begins to contract below 10 ℃, with a shrinkage rate of nearly 60% for high EVA content. The shrinkage stress is smaller than that of polyethylene, and the transmittance to water vapor, air, nitrogen, and carbon dioxide is slightly higher than that of polyethylene.