Airless-System with inner-bag of DuPont™ Surlyn® preserves make-up properties

Mattitude from Astor, part of the Coty Beauty portfolio of brands, is an oil-free, multi-active make-up, which neither shines nor rubs-off. Of particular note is its airless packaging system from the company Gaplast, based in Saulgrub-Altenau, Germany.

An inner-bag made of DuPont™ Surlyn® plays a major role in ensuring that its delicate content remains germ-free – even after opening – and maintains its creamy-consistency without drying out. Moreover, the innovative packaging concept facilitates the almost entire discharge of the content from the inner-bag, without the bottle losing its elegantly curved shape. Coty is among the first companies to use this multifunctional system for the medium price segment.

The Bag-in-Bottle is produced using coextrusion blow molding and involves the extrusion of a multi-layered tube. Its highly-flexible inner-layer is made from chemically-resistant Surlyn®, while a stiffer polymer is used for the outer-layer. The tube is then transferred to a mold, where it is exposed to an internal pressure to create the desired container form. Polymers offering partial adhesion to Surlyn® are used for the outer-layer. This permits the inner-bag to easily detach from the casing during extraction of the content using a special airless pump. As the content is dispensed, the bag collapses in on itself – preventing the ingression of air and thus the drying out of the content, or its premature deterioration. The result is a consistently high-quality make-up in a packaging that maintains its attractive appearance until it is empty.

“We can manufacture under clean-room-like conditions (conforming to EU-GMP guidelines) and test each separate airless system for air tightness, thus ensuring our packaging meets the high hygienic requirements,” explains Stephan Kneer, research and development manager at Gaplast. “Our concept is ideally suited to cosmetic applications, perishable food items or even the dosage of liquid or paste-based medication – eye-drops, for example, where germ-free packaging plays a critical role. Surlyn® provides specific benefits for this application. Due to its softness and flexibility, the inner-bag collapses uniformly, facilitating the virtually complete emptying of the container, while its excellent ductility permits a high degree of design freedom. The excellent processing performance of Surlyn® is of further benefit. Its broad processing window facilitates its coextrusion with a number of other thermoplastics, which are used as either an outer-casing or – in certain applications – as an additional, functional layer.”

“The elegant and flattering shape of the packaging developed for Astor Mattitude is a further example of the unusual and diverse designs made possible by the Airless System,” adds Leonie Kneer, sales and marketing manager at Gaplast. “Such design freedom applies as much to large-volume bottles of household cleaner as it does to smaller cosmetic packaging requiring a sophisticated optical presence. Whenever sensitive contents need protecting, the Airless System with an inner-bag made of Surlyn® provides a solution which is as high in quality as it is reliable.”