| 摘要 |
An improved apparatus for forming noncircular cupped articles from thermoplastic sheet by plug-assist drawing of the sheet in solid phase comprises a plug or mandrel with recessed sides in at least about the upper half of the mandrel. Plug-assist drawing of noncircular containers, such as square or rectangular containers having rounded edges, from thermoplastic sheet in the solid phase, utilizing a plug with recessed sides according to this invention, results in articles having greatly improved uniformity of wall thickness in the edges and sidewalls, when compared with drawing by means of a plug in which the sides are not recessed. |
