Stretch film, also known as stretch film and heat shrink film, is the first in China to produce PVC stretch film with PVC as base material and DOA as plasticizer and self-adhesive effect. Due to environmental protection issues, high cost (relative to PE's high proportion, less unit packaging area), poor stretch-ability, etc., it was gradually eliminated when the domestic production of PE stretch film was started from 1994 to 1995. The PE stretch film first uses EVA as the self-adhesive material, but its cost is high and it has a taste. Later, PIB and VLDPE are used as self-adhesive materials, and the base material is mainly LLDPE. Stretch film can be divided into: PE stretch film, PE stretch stretch film, LLDPE stretch stretch film, PE slit stretch film, etc.   Features of Stretch Film 1. Unitization: This is one of the biggest characteristics of stretch film packaging. With the help of the film's super winding force and retractability. 2. Primary protection: Primary protection provides surface protection of the product, forming a very light and protective appearance around the product, so as to achieve the purpose of dustproof, oilproof, moistureproof, waterproof and anti-theft. It is especially important that the stretch film packaging makes the packaged items evenly stressed and avoids damage to the items caused by uneven force, which is not possible with traditional packaging methods (bundling, packing, tape, etc.). 3. Compression fixity: The product is wrapped and packaged with the help of the retraction force of the stretch film to form a compact, space-saving unit, so that the product trays are tightly wrapped together, which can effectively prevent the transportation process The mutual dislocation and movement of the middle products, and the adjustable stretching force can make the hard products stick closely, and make the soft products shrink, especially in the tobacco industry and the textile industry, which has a unique packaging effect. 4. Cost saving: The use of stretch film for product packaging can effectively reduce the cost of use. The use of stretch film is only about 15% of the original box packaging, about 35% of the heat shrinkable film, and about 50% of the carton packaging. At the same time, it can reduce the labor intensity of workers, improve packaging efficiency and packaging quality.