Lactra SX light blocking additive, which is marketed by PolyOne’s ColorMatrix business, protects liquid dairy products packaged in mono-layer PET bottles from degrading due to light radiation.
Since the launch of Lactra SX last year, and as part of a planned testing protocol, PolyOne has carried out a series of comparative laboratory tests to the light-blocking additive to understand specific performance levels.
Solution to a problem
The long shelf life of UHT dairy products makes them more susceptible to light-induced oxidation, so they require special packaging to ensure a long shelf-life.
Light-induced oxidation causes degradation reactions in dairy products and a decrease in nutritional quality. Vitamins A, B2 (riboflavin), D and amino acids become lost, lipids (milk fats) oxidize, and off-flavors can develop due to the resulting decomposition products.
Traditionally, UHT liquid dairy products have been packaged in laminated paperboard cartons, pouches, or multilayer high density polyethylene (HDPE) and polyethylene terephthalate (PET) bottles.
PolyOne said its ColorMatrix Lactra SX light blocking additive also expands design freedom by allowing designers to use a single PET layer bottle to create the same visible light blocking as paperboard and multilayer HDPE and PET packaging.
As a result, light induced oxidation is minimized, properties and taste are preserved.
The company said the light blocking additive can be added to PET using a single-stage process for monolayer bottles, resulting in lower machinery costs and no loss in light blocking performance.
The monolayer injection process can also lead to reduced production costs and has the potential to offer lighter-weight bottles due to fewer restrictions in bottle wall thickness for single layer constructions.