PET is a material with good barrier properties for many food, medical and cosmetic products. In many cases, it offers sufficient protection during the required shelf-life of these products. There are different solutions for a number of products that need additional protection against the entry of, for example, UV light or oxygen
- Barrier additives: these are additives that can be added in liquid form or as Master Batch
- Coating: This can be applied both internally and externally
- Multilayer: An intermediate layer with a barrier
Additional UV protection
To improve the products’ protection against the influence of (UV) light, a UV additive can be added. There are types that capture different wavelengths in the UV range. For example, UV protection is added to herbs and spices to protect the colour of the product.
All plastics have a certain degree of gas permeability. An additive with the effect of an oxygen barrier can be added to products that are sensitive to the effects of oxygen in order to counter permeability. This will extend the shelf life of the product. For example, when testing a 187 ml PET bottle with wine, it was found that the shelf life was extended from 3 to 18 months by adding an oxygen barrier additive.
Water vapour barrier
Increasing the water vapour barrier is possible by applying a coating on the inside (e.g. SiOx Coating). There are also ongoing developments with nano additives.