Moulded screw cap for sealing PET bottle - has circular internal sealing lip on underside of top which has curved section and is pressed against inside of bottle neck when screwed on

摘要

A plastic sealing cap esp. for PET bottles has a top with a sealing lip all round on the underside to engage into the mouth of the bottle, and in doing so is pressed radially inwards so as to elastically seal off the inner dia. of the neck of the bottle; the top also has an outer wall with features on its inner face to grip the bottle and (e.g.) with a tamper-proof ring on its lower rim. The sealing lip has a curved cross-section which is convex on the radially outer side where it grips the inner dia. of the bottle neck. ADVANTAGE - The design produces a uniform seal round the whole of the bottle neck even if the interior of the bottle develops a high pressure. The cap is simple so that it can be cheaply mass-produced.