Bi-can having internal bag
View Patent ↗A can assembly includes a can body, and a cap that is seamed to the can body, and a bag. The bag, which may be formed by a thermoforming process, includes a thickened portion as part of a peripheral flange that terminates in a bulb. A throat that receives the bulb is formed by necks on the body and cap such that the bulb is spaced apart from the seam. A constriction formed by the neck radially inboard from the bulb receives the thickened portion of the bag. The process for forming the can assembly includes forming the seam and thermoforming a billet into the bag. At least part of the flange is formed between matched portions of mold flanges.
1. A method of forming a can assembly for dispensing a product under pressure, comprising the steps of:
a) providing a body including a body sidewall, a body neck, and a body seam portion disposed at a distal portion of the body neck;
b) providing a cap including a cap sidewall, a cap neck, and a cap seam portion;
c) providing an inner container including a flange having a bulbous end;
d) placing the flange of the inner container between the cap and the body such that (i) the bulbous end is disposed in an annulus formed between the body neck and the cap neck and (ii) a portion of the flange radially inward from the bulbous end is disposed in a constriction formed between the body neck and the cap neck proximate the annulus; and
e) rolling the body seam portion and cap seam portion together to form a seam, whereby the seam is spaced apart from the bulbous end of the flange.
2. The method of claim 1 wherein the step of 1.c) providing an inner container comprises thermoforming the inner container.
3. The method of claim 2 wherein thermoforming the inner container comprises the steps of:
a) heating a billet;
b) disposing the billet into a mold;
c) deforming a portion of the billet to form the flange of the inner container; and
d) deforming another portion of the billet to form the body of the inner container.
4. The method of claim 3 wherein the step of 3.c) deforming said portion of the billet includes deforming a periphery of the billet between a top mold flange and a bottom mold flange, wherein a space between the top mold flange and bottom mold flange has a shape corresponding the bulbous end of the inner container flange.
5. The method of claim 4 wherein at least one of the top mold flange and the bottom mold flange are movable to enable removal of the thermoformed inner container.
6. The method of claim 4 wherein the step of 3.d) deforming said other portion of the billet includes deforming a central portion with a stretch rod and blown air.
7. The method of claim 1 further comprising the steps of installing a nozzle in a top opening of the cap.
8. The method of claim 1 further comprising the steps of filling an interior of the inner container and pressurizing the can assembly at an exterior of the inner container.