Breaking all the rules: clear, thick walls

Going against all practical molding theory, Merle Norman Cosmetics found a successful blend of processing technique and resin to mold very thick, perfectly clear walls for its new upscale Luxiva brand liquid foundation bottle. Eastman Chemical’s Eastar copolyester AN004 delivered uncompromising clarity at wall thicknesses ranging from 0.50 in. to 0.150 in.

The goal was to find a polymer that could simulate the distinctive clarity and rich substance of thick blown glass. “We prefer to use plastic so that we can create a more unique product,” says John Ramirez, Merle Norman in-house molding manager.

The Eastar material meets FDA requirements, and passed Merle Norman’s rigorous fitness-for-use tests that included submerging AN004 in a liquid foundation for 24 hours at 50C. “I never knew copolyester had such good chemical resistance,” says Ramirez. He adds that the thick walls also contribute to minimizing product weight loss, something that, until now, was only possible with glass or thick-walled opaque and translucent plastic.

This was not a typical injection-blow molding application. Without using a preform, Merle Norman broke new ground by simultaneously injecting and blowing the bottle from a 0.200 in. thick parison.

Eastman Chemical Co. 423-229-2000