CLOSURES FOR PRESSURISED PRODUCTS

摘要

A closure for a pressurised product is formed of a screw-threaded plastics ring (16), and a metal lid (14) held loosely captive in the ring and having a peripheral channel (22) containing sealing compound (42) for sealing with a container neck (12). The ring has a multi-start screw thread, with vent slots (58') formed between or in the thread segments. For pressure relief the lid can distort in a controlled manner so that spreading of the peripheral channel allows gas to escape.