Plastic raw materials are abundant, chemical stability is good, and it is easy to process and produce, and it is widely used in food packaging. Due to its lighter texture, barrier properties, heat resistance and permeability, and rich colors, plastics are favored by many consumers.
However, there are free monomers, lysates, lubricants and colorants in plastics, which are the main factors affecting food safety. In addition, plastics are difficult to degrade, troublesome to handle, and cause serious environmental pollution.
Materials with high barrier properties have become the first choice for environmentally friendly, safe and hygienic food packaging. Among them, EVOH plastic sheet has become an ideal substitute for traditional high-barrier packaging materials such as metal and glass due to its excellent high-barrier properties. At the same time, it has also become the first choice for food, fruit and vegetable food packaging materials.
Since 2016, the market demand for EVOH has increased year by year, and its consumption areas mainly include barrier gas packaging films, gasoline tanks, EVOH multilayer composite bottles, and co-extruded plastic sheets. Among them, barrier gas packaging films and gasoline tanks are the main consumption areas, accounting for about 65%.
According to a newly released market study by Fact.MR, EVOH films in the packaging industry are expected to continue to grow at an annual growth rate of 4.7% over the decade from 2018 to 2028. Research indicates that demand from the food and beverage industry will remain strong as innovative packaging technologies appeal to a wider group of eco-friendly consumers.
EVOH plastic films are highly resistant to oxygen and carbon dioxide and are the preferred packaging material. In addition, EVOH can prevent the penetration of oils and organic solvents, and is used in pharmaceutical products, health products, cosmetics, automobile fuel tanks, etc.
Features of EVOH plastic sheet:
1. Moisture absorption performance
Since EVOH contains hydroxyl groups, it has strong hydrophilic and hygroscopic properties. When EVOH absorbs moisture, its barrier properties will decrease.
2. High barrier properties
EVOH can effectively prevent the penetration of gases such as oxygen and carbon dioxide. Its gas barrier property is 100 times higher than that of PA, 10,000 times higher than that of PE and PP, and dozens of times higher than that of PVDC, which is a commonly used barrier material. In addition, EVOH also has excellent barrier properties to non-polar oils and organic solvents.
3. Mechanical properties
EVOH has good strength, elastic modulus and bending properties, and has a certain mechanical strength. At low temperature EVOH is relatively hard, brittle, and has poor impact resistance. In application, EVOH is generally blended and modified with other substances to solve the disadvantage of poor impact resistance at low temperature, and to improve its bending fatigue resistance, impact resistance, and tensile properties.
4. Environmental protection
During the EVOH synthesis process, no additional additives such as plasticizers are required. Judging from the molecular structure of EVOH, its molecular chain only contains three elements, C, H, and O, which will not produce toxic and harmful substances during processing and burning. It has excellent hygienic properties, is safe and non-toxic, and is a green and environmentally friendly material.
5. Weather resistance, anti-aging
EVOH has excellent aging resistance and weather resistance, and its transparency, gloss, mechanical properties, barrier properties and other changes are small after long-term use.
The blister performance of EVOH is not conducive to food preservation, and this problem can be solved by multi-layer co-extrusion of PP-EVOH. Moreover, the price of PP-EVOH composite material is lower than that of EVOH, and the oxygen barrier and water barrier are good.
The price of EVOH material is about 4 times higher than that of ordinary plastic. EVOH-PP composite material is a plastic material, and under the condition of ensuring the same fresh-keeping effect, the production cost is low, and it has the characteristics of high barrier property, good oxygen barrier and water resistance. Whether it is a film or a blister box, it can be used for the preservation of fruits and vegetables, seafood and aquatic products, rice and cereals, and various ocean-going fresh products.