| 摘要 |
<p>The method and apparatus for forming a sheet of thermoplastic material into a cylindrical sleeve by wrapping the sheet around a cylindrical mandrel with the end portions of the sleeve overlapping, directing a stream of hot air from a duct onto the facing surfaces of the overlapping end portions such that the uppermost end portion is lifted and the hot air softens the facing end surfaces of the thermoplastic sheet, upon the end surfaces becoming softened diverting the hot air away from the end portions, and pressing together the softened end portions with a sealing bar extending longitudinal of the mandrel over the overlapping softened portion.</p> |
