THIN-WALLED BOTTLE OF SATURATED POLYESTER RESIN.

摘要

Thin-walled bottle with of satd. polyester resin has a lower portion with a generally polygonal cross-section defined by flat wall portions (7) meeting at broad ridges (6). At the top and bottom of each flat wall portion (7), there is an internal, inwardly curved skirt portion (12,13), so that the wall portions (7) approximately define ellipses, which are the weakest portions of the bottle.. Negative pressure causes curving of the flat walls about the centres of these ellipses, so that deformation of the bottle is generally uniform, and external appearance of the bottle remains quite good and lettering, etc. can still be read.