PETpla.net Insider 12 / 2016

COLOURANTS / ADDITIVES 10 PET planet Insider Vol. 17 No. 12/16 www.petpla.net UV and light absorbers protect brand integrity Proper light protection It has always been essential for brands to protect their product’s integrity. An increasing number of products such as beer, juices, milk, energy drinks and vitamin-enhanced beverages, as well as household cleaners and dishwashing liquids are being packaged in PET. This raises the question of how best to protect them. Holland Colours’ LightGuard series claims to provide an answer. Many of the products being pack- aged in PET – or considered for PET packaging – contain colour, flavour, nutritional or functional components that need to be protected against UV radiation and light from both sunlight and fluorescent lighting in stores. Product integrity – and, ultimately, brand integrity and reputation – depend on giving proper care to pre- venting the content from deteriorating through exposure to UV and light. That has traditionally been a weak- ness of transparent PET. Building UV and light protection into the PET package itself offers several advantages beyond simply keeping prod- ucts fresher for longer. Among these benefits is increased flexibil- ity in formulating with components that are expected to be some- what sensitive but whose matrix effects are unknown. It also makes it pos- sible to eliminate the use of UV stabilisers in the product itself. This in turn allows brands to increase the percentage of natural components without having to add chemical UV sta- bilisers to the formulation. In addition, the UV protection can be optimised in the container wall instead of in the product, independent from product formulation issues or package design changes. This is where Holland Col- ours’ LightGuard series comes in. The product integrity challenge The backstory to the problem is that in PET packaging terms, the hazardous UV and light spectrum ranges from 320 to around 550nm, depending on product composi- tion and shelf life expectations. PET itself only absorbs light up to 320nm, which means PET bottles need addi- tional UV and light protection if they are to be used to contain light-sensi- tive products. Many commercially available UV absorbers, however, only extend the level of protection to 370nm. This is sufficient for many products. Several common colourants and vitamins, for example, appear to be quite stable when tested in isolation with this level of protection. But there are many other components that, when used in complex formulations, show an increased sensitivity due to matrix effects. In other words, com- ponents that are otherwise stable to UV and light can be affected by exposure due to interaction with less stable components. They then create an unexpected negative influ- ence on another component that in turn leads to decreased product integrity. Trial and error or guaranteed performance The result of this can be unex- pected losses in functionality and colour. This leads to a shorter product shelf life for sensitive prod- ucts. Because every formulation can behave differently, extensive testing is required to determine each prod- uct’s exact and individual UV protec- tion requirements. This is both very time-consuming and expensive, which means that for complex products, it is simpler and more secure to skip the testing altogether and go for a product that blocks all radiation all the way up to 400nm, thereby blocking all UV radiation while maintaining a colour- less transparent bottle. PET additives Holland Colours’ LightGuard series of UV and light absorbers is said to provide protection from 370nm up to 400nm in the UV range, and all the way from 400nm up to 700nm for light-sensi- tive products.