Polypropylene tray for holding glass ampoules - has deep sidewalls, stiffening the tray and gripping the ampoules better

摘要

A tray for supporting rows of glass ampoules to be filled under vacuum is made from sheet plastic (polypropylene) so that two opposing sides are folded inwards and downwards to bear elastically against the adjacent rows of ampoules. The other sides have their crests folded obliquely inwards to bear against the remaining peripheral ampoules. The extra height and double thickness of the first pair of walls stiffens the tray and provides a better grip on the ampoules than a conventional tray with rising lips on all four sides. Arrangement is esp. claimed for trays made by folding and ultrasonic welding of extruded expanded propylene copolymer sheet, the cells on the edges of the cut sheet also being heat sealed.