PE is one of the most common materials in plastic packaging. It has good moisture resistance and air permeability, and is widely used in food packaging. But some products are not suitable for the use of PE film, today to summarize for you.
1, vegetable oil fried food or food containing vegetable oil
PE (polyethylene) plastic film in the actual process of drawing or blowing, in order to enhance or complement the performance of the film, high pressure polyethylene, low pressure polyethylene and linear polyethylene are often used in proportion. The film is named after which substance has the highest proportion. For example, milk packaging film contains high pressure polyethylene composition, called high pressure polyethylene film. Yogurt, convenient bag packaging film containing low - pressure polyethylene, it is called low - pressure polyethylene plastic film.
Although PE (polyethylene) fresh membrane permeability good (package is keep fruits, vegetables, water and carbon dioxide gas effect), but, after contact with vegetable oil, PE (polyethylene) film will permeate, swelling, discoloration, such as food packaging contain vegetable oil, not only can greatly shorten the shelf life of food, and long-term exposure to vegetable oil, The "naphthalene" in PE (polyethylene) film will precipitate into vegetable oil, harmful to human health, so PE (polyethylene) film should not be used to package fried food and food containing vegetable oil, also should not be packed with oil melon seeds, dried fruit seeds, nut seeds and other food.
2. Milk packaging
Co-extruded PE (polyethylene) plastic film packaging, the current market popular milk packaging, milk products packaging, soy sauce, vinegar packaging is a typical co-extruded plastic film packaging. Transparent non-printing vacuum or cooking packaging bags, also co-extruded plastic film packaging. The current milk packaging, although the use of white inside black and white co-extruded plastic film, to extend the warranty period. But if the use of three layers of co-extruded plastic film, due to the lack of barrier layer, and rarely can reach the quality of the packaging marked period.
With EVOH (ethylene/vinyl alcohol copolymer) barrier layer of five layers of co-extruded and coated PVA (polyvinyl alcohol) barrier layer of plastic film, can extend the quality of life but the cost is higher. In today's market, where only price competition is possible, some companies use two or three layers of co-extruded black and white plastic film and PE film, which is symbolically coated with barrier material, to pack milk, dairy products, soy sauce, and vinegar. Then mixed with black master material of PE (polyethylene) film direct contact with milk, milk products and soy sauce, vinegar, then inert carbon black pigment will infiltrate (packaging will be contaminated). So symbolically coated with barrier material plastic film, can cope with the examination and testing, but can not play the role of barrier, also can not guarantee the shelf life of the contents.
Currently on the market many of PE (polyethylene) convenience bag and even volumes bags in the hand is upset, but many bag manufacturers to reduce cost, add a lot of filling material, the transparency of the bag, open sex, lower strength, odor, though the printing on the bag of environmental protection and food safety mark and words, but in fact neither using biodegradable materials, Also did not use environmental ink printing, not only increased production costs, but also increased the solvent residue, safety is also a concern.
