Stretch film is also called stretch film and heat shrink film. The PE stretch film first used EVA as the self-adhesive raw material, but its cost increased and there was a peculiar smell. Later, the development trend was to use PIB and VLDPE as self-adhesive raw materials. MPE).

In the early days, most LLDPE stretched films were blown film machines, from a single-sided development trend to two-layer and three-layer. Nowadays, the main body of LLDPE stretched film is produced by the casting method. This is because the production of the casting line has uniform thickness and high definition. Advantages, applicable to the pre-pulling regulations of polymer batteries. Because single-sided casting cannot achieve single-sided and double-sided bonding, the main use suffers from limitations. Single-layer and two-layer casting are not as extensive as three-layer casting in the selection of raw materials, and the formulation cost is also high, so the three-layer co-extrusion structure is more ideal. The high-quality stretch film should have the characteristics of high definition, high vertical elongation, high yield, high transverse tearing compressive strength, and good puncture characteristics.

Classification of stretch film
At this stage, the stretch films currently on the market are divided into two types, hand stretch films and machine tape stretch films, according to their main uses. The thickness of the hand stretch film is generally 15μ-20μ, and the thickness of the machine belt stretch film is 20μ-30μ, except in special cases. According to the packaging method, Lashen stretch film packaging can be divided into pull-type Lashen packaging, vibration-damping Lashen packaging, and pre-Lashen packaging. Classified by material, wrapping film can be divided into high-pressure polyethylene wrapping film, polyethylene wrapping film, butadiene-butyl acrylate wrapping film, etc. At this stage, many winding films used in production and application use linear high-pressure polyethylene as the basic raw material, and high-pressure polyethylene winding films have become popular for winding films. Classified according to the structure of the film, wrapping film can be divided into single-sided wrapping film and double-layer wrapping film. Generally, only one side is adhesive, so it is often called single- and double-sided adhesive wrapping film. With the improvement of film production equipment and technology, the advantages of double-layer wound films that are beneficial to improve product quality and reduce production costs are becoming more and more serious. At this stage, the development trend of single-sided wound films is gradually decreasing. According to different forming production and processing methods, wrapping film can be divided into injection wrapping film and cast wrapping film. The characteristics of cast wrapping film are better. Categorized by main use, wrapping film can be divided into wrapping film for industrial packaging bags (such as wrapping film for household appliances, machinery, chemicals, decorative building materials, etc.), wrapping film for packaging bags for agriculture and animal husbandry, and wrapping wrapping for household packaging bags. Film etc.

The key raw material of the stretch film is LLDPE, and the model involved is 7042. Because of the unique requirements of the film, 7042N, 1018HA, 1002YB, 218N and 3518CB can also be used.

Main use of stretch film
As an indispensable part of freight transportation, stretch film has the effect of fixing immovable goods. It is widely used in the paper industry, freight logistics, chemical plants, plastic raw materials, decorative building materials, food, laminated glass, etc.; in export trade, papermaking, etc. Industries such as industry, hardware, plastic chemicals, decorative building materials, food and pharmaceuticals are also involved. It can be said that wherever there are objects moving from the indoor space, there will be the shadow of the stretch film.