Overview Of The Development Of Stretch Film Industry
Stretch film, also known as pallet packaging. It is the first in China to produce PVC stretch film with PVC as base material and DOA as plasticizer and self-adhesive function. Due to environmental protection issues, high cost (relative to PE, relatively small unit packaging area), poor stretchability and other reasons, PE stretch film was gradually eliminated when domestic production of PE stretch film was started in 1994-1995. PE stretch film first uses EVA as self-adhesive material, but its cost is high and tasteful. Later, PIB and VLDPE are used as self-adhesive material. The base material is now mainly LLDPE, including C4, C6, C8 and metallocene PE. (MPE). Now the northern part of China is represented by the "TOPEVER" stretch film produced by Shandong Topever Group, which has won the favor of customers from many countries.
Early LLDPE stretch film was mostly blown film, from single layer to two-layer and three-layer; now LLDPE stretch film is mainly produced by casting method, because the casting line production has the advantages of uniform thickness and high transparency. It can be applied to the requirements of high ratio pre-stretching. Since single-layer casting cannot achieve single-sided sticking, the application field is limited. Single-layer and double-layer casting are not as wide as three-layer casting in terms of material selection, and the formulation cost is also high, so the three-layer co-extrusion structure is more ideal. A high-quality stretch film should have the characteristics of high transparency, high longitudinal elongation, high yield point, high transverse tear strength, and good puncture performance.
Classification Of Stretch Film
At present, stretch films on the market are divided into two types: hand stretch films and machine stretch films according to different uses. The thickness of stretch film for hand is generally 15μ-20μ, and the thickness of stretch film for machine is 20μ-30μ, except for special cases. According to the packaging method, stretch stretch film packaging can be divided into manual stretch packaging, damping stretch packaging, and pre-stretch packaging. Classified by material, stretch film can be divided into polyethylene stretch film, polyvinyl chloride stretch film, ethylene-vinyl acetate stretch film, etc. At present, the stretching films used in mass production are all based on linear polyethylene, and polyethylene stretching films have become the mainstream of stretching films. According to the structure of the film, the stretch film can be divided into a single-layer stretch film and a multi-layer stretch film. Generally, only one side is sticky, so it is often called a single-sided sticky stretch film. With the improvement of film production equipment and technology, the advantages of multi-layer stretched films, which are conducive to improving product quality and reducing product costs, have become increasingly prominent. At present, stretched films with single-layer structures have gradually decreased. According to different molding and processing methods, stretch film can be divided into blown stretch film and cast stretch film, and cast stretch film has better performance. Classified by application, stretch film can be divided into stretch film for industrial product packaging (such as stretch film for packaging of home appliances, machinery, chemicals, building materials, etc.), stretch film for agricultural packaging, and stretch film for household packaging.
Stretch Film Raw Material
The main raw material of the stretch film is LLDPE, and the grade involved is mainly 7042. Due to the special needs of the film, 7042N, 1018HA, 1002YB, 218N and 3518CB can also be used.
Stretch Film Use
As an indispensable part of cargo transportation, stretch film plays the role of fixing goods. It is widely used in papermaking, logistics, chemical industry, plastic raw materials, building materials, food, glass, etc.; in foreign trade export, papermaking, hardware, plastic chemicals, building materials, Food, medicine and other fields are also involved. It can be said that wherever there is space transfer of objects, there is the presence of our stretch film.
Stretch Film Production Equipment
In terms of machinery, currently domestic stretch film production equipment is divided into imported lines and domestic production lines. Imported production lines are mainly from Italy, the United States, and Germany; domestic production lines are concentrated in Jiangsu, Zhejiang, Hebei, and Guangdong. And Changlongxing Machinery Manufacturing Factory are well-known in China. Shandong Topever Group has now introduced a number of imported production lines to cooperate with more than ten domestic production lines for production deployment. According to many years of understanding of the industry, the production capacity of the equipment is different in different places. The production speed of the domestic production line is 80-150 m/min. In recent years, the domestic high-speed equipment of 200-300 m/min is in the research and development stage; while the production speed of the imported line has been increased to 300-400 m/min, 500 m/min The high-speed line has also come out. Stretch film casting production equipment varies in price due to different widths and production speeds. At present, the domestic 0.5m thread stretch film machine for hand use is 70,000-80,000/piece, and the machine-use stretch film machine is 90,000-100,000/piece; 1-meter thread is 200,000-250,000/piece; The 2.0-meter line is between 800,000 and 1.5 million/piece.
Post time: Feb-03-2023