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
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
