Barrier Film with PVA Coating Is a Driver of Mono-material Recyclable Packaging
Abstract: PVA coating can make the materials perform good barrier to O2, N2, CO2 and other gas or small molecule volatiles. This article mainly introduces the application characteristics and development prospects of PVA coating in PE//PE mono-material packaging.
At present, recyclable packaging and degradable packaging are two main options for green plastic packaging development. But in fact, it takes a long time for degradable plastic products to be finally integrated into the microbial cycle, and they will still exist in the soil for a long time during this period. At the same time, some products will still produce substances that interfere with the environment or even harmful in the degradation process. What’s more, degradable materials are far from meeting the needs of flexible packaging. Therefore, mono-material recyclable and eco-friendly material is an inevitable choice for the sustainable and high-quality development of plastic packaging.
1. Usage Limitations & Problems of Mono-material Recyclable Packaging
When designing the mono-material recyclable packaging, PE structure has become the mainstream due to its good performance of low temperature resistance, softness and heat sealing strength etc. In the whole recycling circulation, the front-end packaging structure is just as important as the design.Taking the PE/PE mono-material structure as an example, it is still necessary to design the combined functions of the packaging according to different content requirements. So, we need to make various functional modifications to PE.
To facilitate the plastic recycling, we shall always pay attention to whether the performance of the based film itself in the laminated mono-material structure can meet the specific needs, especially the PE/PE structure. The surface PE should realize the printing effect, while the bottom PE should realize the heat sealing function. Meanwhile, it also involves other functional requirements, such as: stiffness of pouch body, drop resistance, puncture resistance, high and low temperature resistance, etc. Plus, certain high barrier performance is required for the recyclable packaging when considering the new mono-material structure. After comparing various barrier coatings, PVA is believed to be the best solution.
