(57) A pressurized thin walled expandable can 10 from which a fluent pressurized product
is dispensed is made from an expandable can wall 12 and a barrier 20, which may be
a fully evertable bag having uniform thickness and flexibility and shaped to fit within
the can wall 12. The open end of the bag is mounted to the can wall 12 by means which
maintain a seal as the can wall expands and returns to its unexpanded condition. As
product to be dispensed is introduced into the product chamber 30, the flexible bag
is extended down into the lower end of the can. As the product is later expelled through
a discharge opening, the flexible bag, which may be plastic, is fully everted into
the upper end of the can to expel all the product. The can is thin walled, so that
when pressurized, the can diameter expands by at least one-thousandth (1/1000) of
its unexpanded valĪ±e. In one embodiment, the bag is mounted by a ring 24 inside the
can. The ring 24 includes a portion which expands to maintain the seal 64 with the
expanding can side wall. In another embodiment the ring 24 is rigid, but of slightly
larger diameter than the can 10. This ring stretches the can, so as to maintain the
sealing contact with the can as the can expands. In other embodiments, the bag may
be mounted by a stretchable adhesive and, if the bag is slightly elastic, it may be
mounted by an adhesive or by a melt seal process such as heat sealing.
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