In the design of single layer recyclable packaging, PE structure has become the mainstream structure with excellent low temperature resistance, flexibility and heat sealing strength. In the meanwhile, the combination and design of different materials are quite important. In order to achieve the protection function of flexible packaging to the contents, when considering the mono environmental protection structure, the recyclable packaging must have a certain high barrier performance.
PVA coating, a layer of transparent polyvinyl alcohol on base material BOPP, PET, NYLON. PVA coating supports good barrier function against gases such as oxygen, nitrogen, carbon dioxide and small molecular volatiles. It is mainly used to improve the gas barrier performance of flexible packaging materials. And PVA coating has a good protective effect on contents with high oil, easy oxidation and deterioration, browning and aroma escape.
The data shows that PVA coating keeps relatively stable after 7 days' high temperature and high humidity. No matter which substrate was kept, the OTR could be within 3.5cc/m2/day. PVA coating has good oxygen barrier and anti-aging properties. It is also helpful to realize the visualization of contents and the lightweight of packaging, rather than metallized film.
In addition, because the molecular structure of PVA and PE is relatively similar, and the use amount is very small, they can be recycled together. PVA coated film could replace some barrier materials like PVDC coated film, EVOH film.Single Side PVDC Coated PET Film