A mold (102, 103, 15, 201, 25)
system for molding a container (22) is described. The mold (102, 103, 15, 201, 25)
system comprises: a mold (102, 103, 15, 201, 25), the mold comprising a mold cavity (115, 203) and an opening (117); and a mandrel (123, 125, 403)
system, the mandrel system comprising a reference point (133), a mandrel (123, 125, 403), and an expandable member (123, 125). The mandrel (123, 125, 403) is at least partially located or at least partially loadable inside the expandable member (123, 125), and includes one or more apertures (135) through which a fluid, in use, can flow from the inside of the mandrel (123, 125, 403) to the outside of the mandrel (123, 125, 403) to expand the expandable member (123, 125). When the mandrel (123, 125, 403) is at least partially inside the expandable member (123, 125), the system of mandrels (123, 125, 403) is positionable relative to the mold (102, 103, 15, 201, 25) such that the reference point (133) is in a
fixed position relative to the mold (102, 103, 15, 201, 25), and the mandrel (123, 125, 403) and the expandable member (123, 125) extend through the opening (117) into the mold cavity (115, 203), the expandable member (123, 125) is configured such that there is a gap between the expandable member (123, 125) and a base (119) of the mold cavity (115, 203) opposite the opening (117). At least a portion of the expandable member (123, 125) and the mandrel (123, 125, 403) is movable relative to the reference point (133) to vary the gap.