Self-pressurized container having a convoluted liner and an elastomeric sleeve

A self-pressurized container comprising:

• (a) a liner/sleeve assembly comprising (1) an elongated radially expandable generally cylindrical flexible plastic liner open at one end and closed at the other end, said liner being of sufficient thickness to be self-supporting in the unstressed state and having upper sidewall means adjacent to the open end and a regularly convoluted portion comprising a plurality of longitudinally extending convolutions extending from said neck portion toward the closed end, said liner having an outwardly turned flange at the open end thereof, said liner having an essentially uniform thickness in the range of about 0.010 inch to about 0.020 inch over its entire length except optionally adjacent to the closed end;
• (2) an essentially cylindrical elastomeric sleeve open at both ends and surrounding at least a major portion of said liner in tight fitting relationship, with no structural element between said liner and said sleeve the normal inside diameter of said sleeve being substantially smaller than the exterior diameter of the liner in its folded state, said sleeve being free to elongated axially and having an axial length at least about 25% greater in the pressurized state than in the non-pressurized state;
• (b) a housing comprising a sidewall and an essentially rigid annular dome, said dome having a central opening and a ring surrounding said opening;
• and
• (c) a valve assembly including a valve for dispensing fluid material from the interior of said plastic liner, an essentially rigid cup having an upstanding sidewall and a vertical tubular stem for discharge of said fluid material, the upper portion of the sidewall of said cup including said flange being crimped against the ring of said dome with the open end of said liner being clamped therebetween.

A method for making a self-pressurized container which comprises:

• (a) molding a moldable material essentially the same thickness throughout, into an elongated generally cylindrical self-supporting flexible liner open at one end and closed at the other end and having, as molded upper sidewall means adjacent to the open end, an outwardly turned flange at the opened and a regularly convoluted portion comprising a plurality of longitudinally extending convolutions extending from said upper sidewall means towards the closed end said liner as molded having an essentially uniform thickness in the range of about 0.010 inch to about 0.020 inch over its entire length except optionally adjacent to the closed end thereof;
• (b) inserting said liner into an elastomeric sleeve with no structural element between said liner and said sleeve, said sleeve having an inside diameter substantially smaller than the exterior diameter of the liner in its folded state and an axial length less than that of said liner, so that the upper sidewall means and the closed end of said liner protrude from said sleeve when both said liner and said sleeve are in the non-pressurized state, said sleeve being free to elongate axially and having an axial length at least about 25% greater in the pressurized state than in the non-pressurized state;
• (c) placing an annular essentially rigid dome having a central opening and a ring encircling said opening so that said ring is in touching engagement with the outside surface of the upper sidewall means;
• (d) placing a valve assembly which includes a metal cup having a bottom portion and an upstanding sidewall means, so that said cup is in contact with the inside surface of the upper sidewall means of said liner;
• (e) crimping the upper edge of the sidewall means of said cup against said ring, with the part of the upper sidewall means of said liner clamped therebetween as a gasket material to form a fluid tight seal between said cup and said liner;
• and
• (f) assembling any remaining housing components to form said container.