Polyvinyl alcohol modified high barrier film and its application
Polyvinyl alcohol modified high barrier film and market applications ( the herd)
One, project development, market background
Our research and development of modified polyvinyl alcohol as high barrier film to change rapidly, is to meet the development needs of high barrier packaging. In particular, fresh meat packaging needs, adopts the best barrier, the most inexpensive materials, raw materials, and the processing technology of the close cooperation and interaction, the appropriate processing equipment, processing of raw materials, processing technology cooperation, meet the packaged product is best.
At present, the market for high barrier multilayer coextruded film with polyamide ( PA ) and ethylene vinyl alcohol copolymer ( EVOH ), polyvinylidene chloride ( PVDC ) and polyolefin resin composition, preparing multi-layer coextrusion of functional thin films. Popular packaging market, especially in the PVDC, EVOH, PA, whereby a single double barrier resin coextruded multilayer composite extrusion of high barrier packaging materials, has replaced the traditional to dry composite method to realize multi-functional, multi-purpose barrier packaging. As the market of packaging function increases as well as the awareness of environmental protection, product cost price is more important. Using EVOH however, because of its deadly water resistance, environment resistance, high price, make the entire packaging market on the high-barrier multi-layer coextrusion film at. Especially in many countries to more PVDC resin as a barrier material. PVDC resin containing chloride monomer, processing is easy to produce harmful gases and air pollution and package goods, because no alternatives but not widely used. Some developed countries have banned do food contact packaging. However, the market is looking forward to a more reasonable cost-effective, and can replace the new barrier resins is done with PVA multi-layer co-extruded high barrier materials, should be the inevitable development trend.
In two, high barrier packaging materials market
Barrier packaging refers to oxygen, water vapor, carbon dioxide has high permeability resistance, mainly used for food, medicine, chemical packaging. At present, food packaging plastic packaging the largest proportion, packaging quality was affected by food spoilage, taste loss is one of the important factors.
( 1) the high barrier resins
High barrier packaging material is the key of barrier resins, the most important is the PVDC, EVOH, special nylon ( MXD6 ), PA, PVA ( for coating ) mainly. Application of PVDC has the longest history, containing a halogen, to recycling, incineration and high cost; EVOH resin molecules containing hydroxyl, can form hydrogen bond with water molecule and reduce the permeability resistance, permeability resistance varies with humidity increase and decrease, so EVOH ethylene content in high grade permeability resistance, water absorption of small, influence of moisture, and low ethylene content grades a barrier with humidity rises faster; PA has a barrier, but the absorption rate is high, affect the permeability resistance, and low temperature to harden; MXD6 than PA6 high melting point, so a high heat resistance, increased with the increasing of humidity, permeability resistance drop is very small, but the relatively high price. At present, being of plastic packaging group thinks promising high barrier materials are EVOH and PVDC, but PVDC is due to the lack of alternative products are still widely used.
( 2) a barrier resin Market Application
PVDC resin is mainly applied in the casing and all kinds of fresh keeping quality packing. At present in our country is only used in high-temperature ham sausage on the PVDC film has more than 50000 tons of market. For the film market is great. Fresh meat products, packaging, pharmaceutical, high-temperature cooking food, seafood, dairy products