Plastic closure

Abstract

A closure is formed from a laminate or composite. The laminate is sufficiently flexible to permit it to assume the surface configuration of the rim of a closure without the need for a gasket. The laminate may include an upper layer which is rigid and a lower layer which is softer and has a lower softening temperature than the upper layer. An optional intermediate oxygen-impermeable layer such as ethylene vinyl alcohol can be included between the upper and lower layers. Preferably, the upper layer is a rigid material such as polyethylene terephthalate or polyvinyl chloride and the lower layer is a soft material such as linear low-density polyethylene. The upper layer provides the necessary strength, while the lower layer provides a tight seal on the rim of the container. The intermediate or bottom layer can also include an oxygen indicator which changes color upon exposure to oxygen.

Dependencies are inferred from the claim text.