DuPont (Wilmington, Delaware / USA; www.dupont.com) says its new over-moulding technology provides greater design freedom for rigid cosmetic packaging. The technology involves the encasing, or over-moulding, of a hollow polymer insert with a thick exterior wall of durable “Surlyn” PC 2000 thermoplastic resin.

Prosper Zufferey, processing expert at DuPont Cosmetic Solutions, said the new development enables the production of intricate shapes and decorative effects, such as sophisticated colours and metallic and fantasy coatings, frosted and unusual tactile properties – which can be difficult to achieve in extrusion blow moulding.

“We are currently working with PET or PP as the material for the polymer insert, as they provide sufficient resistance to the chemicals found in cosmetic lotions,” he said. “For more chemically-aggressive fragrances we are working on the development of multilayer polymer inserts produced by extrusion blow moulding.”

The technology was developed by DuPont affiliate DuPont Mitsui Polychemicals, a joint venture between DuPont and Mitsui (Tokyo / Japan; www.mitsuichem.com). It can be used for the scrap-free production of thick-walled bottles and containers with a minimum wall thickness of 10 mm.