An inner cannula (20) for a tracheostomy tube is made by extruding tubing (41) and cutting into separate lengths or preforms (42). Each preform (42) is placed in a mould (50, 51, 52) and blow moulded to expand the preform into contact with an inner surface (53, 54) of the mould which is shaped to produce a pattern on the outside of the preform of two intersecting diagonal corrugations (211, 212) that act to strengthen the blow moulded preform against lateral forces. The inner surface of the mould may also be textured so that the blow moulded preform is given a texture (213) to reduce friction with the outer tube (1).

An article of footwear may include an upper forming a void within the footwear, a sole structure secured to the upper, and a chamber that encloses a pressurized fluid. The sole structure includes a depression. The chamber is located within the void of the upper and located on the depression of the sole structure. The chamber may include a plurality of fluid-filled subchambers, a manifold, and a connection fluidically-connected at least one of the subchambers to the manifold. The subchambers may enclose the pressurized fluid at different pressures. The subchambers may be separated from one another by a bonded area in the direction extending between the heel and toe of the chamber.

Provided is a method for making barrier tube shoulders. The method includes forming a parison from a multi-layer laminated structure having an inner layer that faces an interior of the parison, an outer layer comprising an exterior surface of the parison, and an interdisposed layer between the inner layer and the outer layer, wherein the interdisposed layer is a flavor barrier layer. The method also includes providing an extrusion blow molding (EBM) mold comprising at least one cavity shaped as a barrier tube shoulder, positioning the parison in the EBM mold, and blow molding the parison such that the parison substantially conforms to the EBM mold to form a barrier tube shoulder having the barrier layer.