Method of forming a headed thermoplastic tube

A method of forming a headed thermoplastic tube from an extruded cylinder of thermoplastic material have a continuous wall with inner and outer wall surfaces, comprising:

• positioning a thermoplastic, extruded, longitudinally stretched, cylinder over a forming mandrel having a head forming end, with an exposed portion of said thermoplastic cylinder, having an open end, extending beyond said head forming end;
• directing a hot fluid against the inner wall surface of the exposed portion of the thermoplastic extruded, longitudinally stretched, cylinder and away from the head forming end of said forming mandrel, by use of a hot fluid nozzle inserted into the open end of said exposed portion of said thermoplastic cylinder, to heat said inner wall surface to a temperature above the glass transition temperature of said thermoplastic material, while maintaining the outer surface thereof below said temperature so as to provide support for said exposed portion, such that the heated exposed portion of said thermoplastic, extruded, longitudinally stretched cylinder is shaped into a conical shape by said heating which causes longitudinal shrinking and thickening of the wall of said heated exposed portion;
• and
• then further heating the outer surface of said heated exposed end to further shape said heated exposed portion of said thermoplastic extruded, longitudinally stretched, cylinder into a conical shape;
• and
• applying pressure to the conical shaped exposed portion if said thermoplastic cylinder to form a headed thermoplastic tube.