Patent ID: 8226867
Filing Date: 2012-07-24
Classification: B29C,B29K,B29L,B65D

Abstract:
1. A method for the production of caps having a heat shrinkable skirt comprising: (a) extruding a thermoplastic material to form a tube having a first diameter D (b) drawing the tube in an axial direction, the axially drawn tube having a second diameter D (c) providing a cooling assembly and cooling the drawn tube in the cooling assembly; (d) providing a radial expansion assembly having an annular vacuum chamber and increasing the diameter of the drawn tube in the radial expansion chamber to form a radially-expanded tube having a third diameter D (e) passing the radially-expanded tube through an axial tension assembly; (f) segmenting the radially-expanded tube into portions of desired length; (g) forming a cap blank by heat shrinking one of the portion on a mandrel; and (h) providing a head on the cap blank to form a cap having a head and a skirt.