| Modern requirements for developing PET containers include an increased need for protecting the contents, with a resulting extension of shelf life to preserve the taste, color and nutritional and functional properties of their products.
Protecting the product from UV radiation is of essential importance as they cause degradation both of the containers and, more importantly, their contents.
Clariant (Italia) S.p.A. offers and develops a variety of solutions focused on increasing UV protection and product shelf life, including giving the polyester barrier properties against UV radiation up to 400 nanometers.
PET, with a 350 micron thickness, absorbs UV radiation up to about 310 nanometers (see fig.1), and does not provide effective protection between 320 and 400 nm but with the addition of CESA®-light additives to specific masterbatches this extends the UV protection to 360 nm and above, to the limit of 400 nm, considered the last threshold of UV radiation. |  |
| Fig 1. shows how UV protection can be improved and differentiated depending on the sensitivity of the contents and marketing needs; with the use of specific UV filters, the ultraviolet radiation can be reduced by 80% and above to the point of achieving almost total protection.
The UV transmittance curve for CESA®-light 7501 shows a level of ultraviolet reduction generally accepted in the cleanser sector where the radiations of wavelengths below 360 nm are completely filtered and rays over 370 nm are less or equal to 5%.
For particularly critical sectors, typically for the food and cosmetics industries, considerable efforts have been made to increase protection to higher levels. Now it is possible to cover the entire field of ultraviolet radiation. |  |
 | For example, the protection that can be achieved with CESA®-light NTA0050119-ZN, which covers up to 400 nm, provides optimal protection in the entire ultraviolet region.
Due to growing needs for improved preservation of nutritional and organoleptic properties of especially sensitive types, new systems of UV absorbers were developed in combination with specific colors in order to extend the protection in the visible range while maintaining the transparency of the PET containers. This is extremely important for the packaging of particularly sensitive products like beer.
Thanks to the characteristics of our UV absorbers combined with a specific range of colors Clariant collaborates with the most important beer brands for their PET bottles. |