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Classification of polyethylene film
Plastic film is one of the most important flexible packaging materials. There are many types of plastic films with different characteristics. According to the different characteristics of the film, their uses are also different. Here are some common plastic films:
PE film uses a large amount of Wholesale One Way Vision film the largest plastic packaging film, accounting for more than 40% of the total consumption of plastic film. Although PE film is not very ideal in terms of appearance and strength, it has good toughness, moisture resistance and heat sealing performance, and is easy to process and form, and the price is cheap, so it is widely used.
1. Low density polyethylene film. LDPE film is mainly produced by extrusion blow molding and T-die method. LDPE film is a flexible and transparent film, non-toxic and odorless, and the thickness is generally between 0.02 and 0.1 mm. Has good water resistance, moisture resistance, drought resistance and chemical stability. It is widely used in general moisture-proof packaging of food, medicine, daily necessities and metal products and packaging of frozen food. However, for articles with high hygroscopicity and high moisture resistance requirements, it is necessary to use films and composite films with better moisture resistance. LDPE film has high air permeability, no aroma retention and poor oil resistance, so it cannot be used for the packaging of easily oxidized food, flavored food and oily food. However, the good air permeability makes it suitable for the fresh-keeping packaging of fresh items such as fruits and vegetables. LDPE film has good thermal adhesiveness and low-temperature heat-sealability, so it is often used as the adhesive layer and heat-sealing layer of composite films. However, due to its poor heat resistance, it cannot be used as the heat-sealing layer of retort pouches.
2. High-density polyethylene film. HDPE film is a tough translucent film with milky white appearance and poor surface gloss. The tensile strength, moisture resistance, heat resistance, oil resistance and chemical stability of HDPE film are better than LDPE film, and it can also be heat sealed, but the transparency is not as good as LDPE. HDPE can be made into a thin film with a thickness of 0.01mm. Its appearance is very similar to that of tissue paper, and it feels comfortable. It is also called a paper-like film. It has good strength, toughness and openness. In order to enhance the feeling of paper and reduce the cost, a small amount of light calcium carbonate can be added. HDPE paper-like film is mainly used to make various shopping bags, garbage bags, fruit packaging bags and various food packaging bags. Because of its poor air tightness and no aroma retention, the storage period of packaged food is not long. In addition, because of its good heat resistance, HDPE film can be used as a heat sealing layer for retort bags.
3. Linear low density polyethylene film. LLDPE film is a new type of polyethylene film developed recently. Compared with LDPE film, LLDPE film has higher tensile strength, impact strength, tear strength and puncture resistance. With the same strength and performance as the LDPE film, the thickness of the LLDPE film can be reduced to 20-25% of Wholesale Color Cutting Vinyl the LDPE film, thus greatly reducing the cost. Even if it is used as a heavy packaging bag, its thickness only needs 0.1mm to meet the requirements, which can replace the more expensive high-molecular-weight high-density polyethylene. Therefore, LLDPE is very suitable for daily necessities packaging, frozen food packaging, and is also widely used as heavy packaging bags and garbage bags.
