Abstract: An improved extrusion apparatus for extruding a tube of soft thermoplastic material of improved consistency and homogeneity is provided. A double walled piston having an annular chamber between the inner and outer annular walls thereof is mounted for sliding longitudinal movement between the interior wall of the apparatus housing and a longitudinal core disposed in the housing. The thermoplastic material fed into the apparatus first enters the annular piston chamber which, even during upward and downward movement of the piston, remains constant.

Abstract: A cylindrical, synthetic plastic container having reinforcing hoops permanently bonded around the ends of the container is manufactured in a single blow molding process. Half of the outer peripheral edge portion of each of two reinforcing hoops is positioned in a semi-cylindrical mold half to place the hoops in spaced, parallel, co-axial alignment. Thereafter, a tube of soft thermoplastic is extruded through the open central portions of the hoops until the end of the tube overlies a co-axially positioned pneumatic nozzle. The semi-cylindrical mold half with the hoops retained therein is moved into engagement with a mating, semi-cylindrical mold half to form a cylindrical mold.