| 摘要 |
<p>Plastic containers are made with a base profile having a rigid centre linked to the root of the vessel walls by a flexible section shaped to be self locking with the centre of the base alternatively higher or lower than the plane of the bottom of the walls. Used esp. for containers blow-moulded from polyethylene for contg. mixts. with volative or fugitive constituents, typically perfumes or cosmetics. The container can be filled with the base distended, leaving sufficient void above the contents for the base to be impressed after fitting the closure. The resultant pressurisation within the container suppresses partial local collapse featured by such containers after partial loss of their contents by permeation. Used to maintain aesthetic appearances longer.</p> |
