Mono-material constructions help to enable bottle recycling

Plastic bottles and containers of diverse sizes and shapes command significant shelf space in the retail arena. The resins, additives and processes used to make these packages vary widely, depending on their contents. Few truly appreciate the complexity involved in manufacturing these containers because, after all –– a clear plastic bottle is a clear plastic bottle, right? Wrong.

The amount of chemistry and technology that goes into ensuring that such containers not only protect their contents, but also are safe, durable, aesthetically pleasing, and environmentally sustainable, can be downright mind-boggling.

Many bottles and containers today rely on multilayer constructions that use a variety of materials to deliver the end result required (such as providing key barrier properties to prevent moisture, UV light and various gases from altering or distorting the contents’ look or performance). Such packaging may yield the necessary performance but can be harmful to the environment. Multimaterial packaging –– with its necessary but disparate, often incompatible layers –– can hinder recyclability.

In many applications –– such as for the packaging of many types of cosmetics, home-care and personal-care products –– polypropylene (PP) can be used not only in the bottles but also in the caps and labels, offering a viable, mono-material solution that doesn’t require adhesives or glues. Such all-PP containers offer greatly enhanced prospects for being recycled into another useful end product.

Milliken’s Millad® NX® 8000 clarifying additive is used to produce the fully transparent material known as NX® UltraClear™ PP, which yields durable end products with superb, glass-like clarity. This makes PP a viable alternative to resins such as PET and polystyrene in a wide range of packaging applications. And the ability to make high-performance, cost-effective bottle caps and in-mold printed labels out of polypropylene as well, makes for a recycling-friendly, mono-material overall solution.