Trend of the hottest green high barrier packaging

Trend of green high barrier packaging materials

at present, the high barrier packaging materials on the market mainly include polyvinylidene chloride (PVDC), ethylene vinyl alcohol copolymer (EVOH) and polyvinyl alcohol (PVA). With the elastic flexion of market strain, the increase of packaging function and the improvement of environmental awareness, the cost performance ratio of products is becoming more and more important. However, PVDC contains chloride ions, and HCl gas is produced in the process of processing and garbage disposal, polluting the air and packaged goods. Europe and the United States and other regions have begun to restrict and stop using it; EVOH's water resistance and weather resistance have not been solved so far, and the price remains high, which makes the whole packaging market afraid of high barrier multilayer coextrusion film. The water-resistant modified PVA coating film, which is expected by the market to be more reasonable in cost performance and can replace PVDC and EVOH, should be an inevitable development trend

first of all, in nature: water resistant modified PVA coating film is a product with high scientific and technological content and high added value. No matter the selection of raw materials, or the processing and consumption process, it does not release any toxic and harmful substances, which is conducive to environmental protection and green consumption. It is an environment-friendly product

secondly, consumption: with China's entry into WTO, China's economy will usher in a new round of accelerated development, and the consumption of PVA high barrier diaphragm in the packaging industry will continue to increase. The proportion of domestic high barrier packaging materials in the total amount of flexible packaging materials is no more than 10%, far lower than 40% in Japan and the United States. Therefore, there is still a huge room for the potential market demand to rise

thirdly, in terms of benefits: the main components of water-resistant modified PVA are PVA resin and water, and the raw materials are available in the domestic market. Both in performance and price, the product has advantages over the current EVOH coextrusion film and PVDC coating film, and is an ideal substitute for PVDC coating film

finally, in terms of policy, the Tenth Five Year Plan issued by the former State Economic and Trade Commission in June 2001 pointed out that packaging materials should focus on the development of various food, beverage, drug and other packaging materials to improve the protection function and prolong the shelf life of high barrier packaging materials, thermosetting molding board filling packaging materials, fresh-keeping materials, grain, and then output and print various required experimental curves and experimental reports, mildew and insect proof materials for storage and transportation. On September 28, 2002, the former State Economic and Trade Commission issued the recent development orientation of the industrial industry (Guo Jing Mao ye ye ye [2002] No. 716), which proposed the development of processes and equipment for high barrier containers, packaging materials, multifunctional films, water-soluble films and degradable materials. Therefore, the industrial scope of water-resistant modified PVA coating film in line with the national industrial policy has increased six times compared with 2015

in a word, the water-resistant modified PVA high barrier coating film is a kind of packaging material with green environmental protection, good oxygen barrier performance and high cost performance. The products of this project conform to the development direction of the national industrial policy, and the prospect is optimistic

problems existing in the modified PVA coating film on the market at present

1. water intolerance

many manufacturers coating PVDC are very disgusted with the modified PVA on the market at present, not that they are not interested in the modified PVA, but that the water resistance of the product cannot meet the requirements of use, so they refuse it. According to research, there are such products on the market. According to the experimental analysis, the so-called modification of this kind of products is only the crosslinking and sealing of a few hydroxyl groups of polyvinyl alcohol with modifiers, and most of the hydroxyl groups are still exposed, and these exposed hydroxyl groups have strong hydrophilicity, which is macroscopically manifested as the water resistance of PVA coating layer

2. Color opacity

at present, the modified PVA glue liquid on the market is yellow and opaque, and the end face of the rolled diameter of the coated substrate also shows obvious yellow, and with the extension of time, the color changes from yellow to reddish brown. As a packaging material, this product seriously affects the natural appearance of the package

3. poor stability of glue solution

through the understanding of PVA coating film manufacturers, the existing modified PVA glue solution in the market is greatly affected by temperature, time and pH value. The main performance is that the lower the temperature, the longer the time, and the smaller the pH value, the easier the modified PVA gel is to gel