Apparatus and method of manufacturing stackable containers

A method for manufacturing stackable containers that insures consistent wall thickness, the method comprising:

• a) providing a main mould assembly cylindrical in shape having an open base for receiving a parison;
• b) providing a secondary slidable mould assembly, said slidable mould assembly capable of moving along a central axis of said main mould assembly toward said main mould assembly to engage said main mould assembly;
• c) providing a pair of air pistons parallel to and spaced from said central axis for moving said slidable mould assembly to and from said main mould assembly, arms extending from said air pistons being in line with said air pistons and directly connected to said slidable mould assembly;
• d) expanding said parison until it engages the walls of said main mould assembly and a head of said parison has expanded beyond said open base a predetermined distance;
• and
• e) maintaining said secondary slidable mould assembly in an initial wait-state until said parison has reached its desired expansion and said parison head has expanded to the predetermined distance whereupon said slidable mould assembly moves along the central axis of said main mould assembly toward said main mould assembly to engage said main mould assembly and conforming said parison to the shape of said slidable mould assembly while said parison maintains a uniform wall thickness even when moulding complex shapes and angles.