EVOH (Ethylene Vinyl alcohol Co polymer) is a material comprised of carbon,oxygen and hydrogen, formulated as a resin. This material has gained widespread acceptance in various industries due to its non toxic and almost neutral properties.
Environmental Friendliness
When burned it has been found to have very little negative impact to the environment. This is because the product is not formulated with additives such as chlorine, dioxins and metallic elements that may have an effect on plant and animal life.
Research has found that the EVOH film has outstanding barrier film qualities than the other nylon and LPDE materials.It has therefore been recognized as best for usage in food packaging for maintaining freshness of food and retaining the shelf life of those foods.
Advantages
- Great barrier against ingress of gasses such as oxygen, carbon dioxide, helium and nitrogen. This helps prevent the development of bacteria in packed food products.
- Reduces or entirely eliminates the need for preservatives in food
- The EVOH barriers have great transparent and high gloss appearance hence able to retain the visual appeal of the product forbetter marketability and promotion.
- The material is recyclable and environmental friendly.
Manufacturing Process
This product is manufactured through the co polymerization process, through which the properties of the film are enhanced to make it suitable for the desired final usage. Inpractice, production involves two processes that are polymerization and saponification. The ethylene and Vinyl acetate are polymerized with an initiator / activator compound. Then the “ethylene-vinyl acetate co polymer” is saponified to ethylene Vinyl alcohol Copolymer”
This innovative chemical engineering process produced one of the best packaging products applied not only in foods but other non food products as well. The EVOH resins are now produced through extruders with barrier screws system, able to achieve high productivity and product quality.
PVDC Blown Barrier Films
The PVDC barrier film on the other hand is a multilayer film, which has a PVDC barrier layer at the core level. It has polyethylene skin layers for added toughness and better sealing properties. The polyvinylidene chloride (PVDC) is a homopolymer of vinylidene chloride. It also has good oxygen, moisture and flavors barrier properties as well as good chemical resistance.
Despite its initial popularity in food packaging it was later discovered that it eventually undergoes thermally induced dehydrochlorination at relatively low temperatures. This degradation process continues on exposing the polyethylene sequences to light. This leads to development of undesirable colors for food and product packaging.
The PDVC barriers films and related resins are also non bio degradable, thus have high potential for environmental degradation when wrongfully disposed.
Conclusion
The EVOH barrier film products from Vishakha Polyfab include vacuum pouches, bag liners, bulk liners and other innovative EVOH based products primarily used in packaging. The EVOH technology has higher efficiency as a barrier and greater life time compared to PVDC or even PET. Experience from manufacturers and users show that this type of barrier film is currently the best barrier for oils, creams and volatile polymers.
