Synthetic cork bottle stoppers - of extruded closed-cell foam of polyolefin and ethylene!-methacrylic! acid ionomer with waterproof coating

摘要

Synthetic cork stoppers for liq. containers, e.g., wine bottles, comprise fine closed-cell foam extruded as a rod from a mixt. of polyolefin and foaming agent together with an ethylene-methacrylic acid copolymer based ionomer resin. The rod has a matte surface and a uniform density of 12-17 lb./ft3. The surface is impregnated with a non-levelling coating of moisture-impervious material with high coefft. of friction than the foam, pref. 10-30% beeswax and 70-90% paraffin. The mixt. pref. comprises 60-98%% low-density polyethylene and 0.5-35% ionomer. The stoppers resemble natural cork and are removable with a corkscrew.