Patent ID: 6129880
Filing Date: 2000-10-10
Classification: B29C,B29K,B29L,B65D,Y02W,Y10S

Abstract:
In a method of forming a headed thermoplastic tube having a closure on its head from a longitudinally stretched, extruded thermoplastic sleeve having a continuous wall with inner and outer wall surfaces by:positioning a longitudinally stretched, extruded thermoplastic sleeve over a forming mandrel having a head forming end, with an exposed portion of said longitudinally stretched, extruded thermoplastic sleeve having an open end extending beyond said head forming end;heating he inner wall surface of said exposed portion of said longitudinally, stretched extruded thermoplastic sleeve by a heat source so that the heated exposed portion shrinks and thickens; andpressing the heated exposed portion into a mold cavity to form a head on said longitudinally stretched, thermoplastic sleeve;the improvement which comprises:pressing he heated exposed portion with sufficient force into a closure having an interior cavity formed by at least a bottom wall and a side wall comprised of a material that is incompatible with the material from which said longitudinally stretched, extruded thermoplastic sleeve is comprised so as to form from said heated exposed portion a head on said thermoplastic sleeve to conform to the interior cavity of said closure and to form an orifice in said head during forming of said head with use of an orifice-forming spike on said closure; whereinthe closure used during forming of said head functions as said mold cavity and also functions as the closure for the headed thermoplastic tube having a closure on its head such that the headed thermoplastic tube having a closure on its head is formed in a single pressing step.