HOT FILL CONTAINER HAVING SUPERIOR CRUSH RESISTANCE
A hot fill plastic container has a dome portion with a convex outer surface that defines a maximum outer diameter of the container so as to extend outwardly beyond a main body portion of the container. The generally egg-shaped dome portion enhances the crush resistance of the dome and provides a point of contact between containers when they are placed adjacent to one another. A circumferential stiffening groove may be provided near a lower end of the dome portion.
1 . A method of packaging a product, the method comprising:
hot-filling a heated liquid or semi-solid product into a container, the container having
a finish portion defining an opening,
a main body portion comprising a cylindrical sidewall having a first maximum diameter in plan view,
a dome portion between the finish portion and main body portion, the dome portion having, as viewed in longitudinal section:
an upper end disposed proximate to the finish portion,
a lowermost end disposed adjacent to the main body portion,
a first convex curved portion defining a first constant radius of curvature,
a second convex curved portion defining a second constant radius of curvature that is greater than the first radius of curvature,
and a convex curved non-cylindrical transition portion having a transition curvature connecting the first curved portion and the second curved portion,
wherein the first convex curved portion extends from the upper end of the dome portion to the transition and the second convex curved portion extends from the transition portion to the lowermost end of the dome portion, the dome portion further having a second maximum diameter in plan view that is greater than the first maximum diameter,
and a bottom portion having a standing ring and a cylindrical wall extending between the main body portion and the standing ring, the cylindrical wall having a third maximum diameter;
sealing the opening of the container to define a sealed container; and
allowing the liquid or semi-solid product to cool in the sealed container.
2 . The method of packaging a product according to claim 1 , wherein the container further comprises a circumferential groove defined proximate to a lowermost end of the dome portion, the circumferential groove extending around an entire circumference of the lowermost end of the dome portion.
3 . The method of packaging a product according to claim 2 , wherein the main body portion further comprises a plurality of cylindrical sidewall portions separated by a corresponding plurality of stiffening grooves, the stiffening grooves extending around the entire circumference of the cylindrical main body portion.
4 . The method of packaging a product according to claim 2 , the circumferential groove having a concave radius of curvature R 5 and a maximum depth D G , wherein a ratio of R 5 to D G is within a range of 0.20 to 1.0.
5 . A method of forming a plastic container comprising:
providing a material suitable for a blow molding process;
disposing the material within a mold cavity configured to form a container having
a finish portion defining an opening,
a main body portion comprising a substantially cylindrical sidewall having a first maximum diameter in plan view,
a dome portion between the finish portion and the main body portion, the dome portion further defining a second maximum diameter in plan view that is greater than the first maximum diameter, and
a bottom portion opposite the finish portion,
wherein the dome portion in longitudinal section has a convex outer surface comprising a compound curved shape defined by a first convex portion having a first radius of curvature R 1 , a second convex portion having a second radius of curvature R 2 , and a transition region connecting the first convex portion and the second convex portion; and
inflating the material within the mold cavity to form the container.
6 . The method of forming a plastic container according to claim 4 , wherein a ratio of R 1 to R 2 is within a range of 0.3 to 0.9.
7 . The method of making a plastic container according to claim 5 , wherein the ratio of R 1 to R 2 is within a range of 0.4 to 0.8.
8 . The method of forming a plastic container according to claim 6 , wherein the ratio of R 1 to R 2 is within a range of 0.5 to 0.7.
9 . The method of forming a plastic container according to claim 4 , wherein a ratio of R 1 to the second maximum diameter is within a range of 0.4 to 1.2.
10 . The method of forming a plastic container according to claim 8 , wherein the ratio of R 1 to the second maximum diameter is within a range of 0.55 to 1.05.
11 . The method of forming a plastic container according to claim 9 , wherein the ratio of R 1 to the second maximum diameter is within a range of 0.7 to 0.9.
12 . The method of forming a plastic container according to claim 4 , wherein a ratio of the first maximum diameter to the second maximum diameter is within a range of 0.8 to 0.99.
13 . The method of forming a plastic container according to claim 11 , wherein the ratio of the first maximum diameter to the second maximum diameter is within a range of 0.85 to 0.98.
14 . The method of forming a plastic container according to claim 12 , wherein the ratio of the first maximum diameter to the second maximum diameter is within a range of 0.9 to 0.97.
15 . The method of forming a plastic container according to claim 4 , wherein the first convex portion defines a first vertical height and the second convex portion defines a second vertical height, and wherein a ratio of the first vertical height to the second vertical height is within a range of 1.0 to 7.0
16 . The method of forming a plastic container according to claim 14 , wherein the ratio of the first vertical height to the second vertical height is within a range of 2.0 to 6.0.
17 . The method of forming a plastic container according to claim 4 , wherein the dome portion is shaped so as to be symmetrical about a longitudinal axis.
18 . The method of forming a plastic container according to claim 4 , wherein the main body portion further comprises a plurality of cylindrical sidewall portions.
19 . The method of forming a plastic container according to claim 17 , the plurality of cylindrical sidewall portions separated by a corresponding plurality of stiffening grooves, the stiffening grooves extending around the entire circumference of cylindrical main body portion.
20 . The method of forming a plastic container according to claim 4 , wherein the mold cavity is further configured to form a circumferential groove in the container proximate to a lowermost end of the dome portion, the circumferential groove extending around an entire circumference of the lowermost end of the dome portion.
21 . The method of forming a plastic container according to claim 19 , the circumferential groove having a concave radius of curvature R 5 and a maximum depth D G , wherein a ratio of the concave radius of curvature R 5 to the maximum depth D G is within a range of 0.20 to 1.0.
22 . A method of forming a plastic container comprising:
providing a material suitable for a blow molding process;
disposing the material within a mold cavity configured to form a container having
a finish portion defining an opening,
a substantially cylindrical main body portion having a first maximum diameter, and
a dome portion between the finish portion and the main body portion further defining a second maximum diameter in plan view that is greater than the first maximum diameter,
a bottom portion opposite the finish portion, and
a circumferential groove defined proximate to a lowermost end of the dome portion, the circumferential groove extending around an entire circumference of the lowermost end of the dome portion,
wherein the dome portion has a convex outer surface in longitudinal section comprising a compound curved shape defined by a first convex portion having a first radius of curvature R 1 , a second convex portion having a second radius of curvature R 2 , and a transition region connecting the first convex portion and the second convex portion, and
wherein the second maximum diameter is defined by the second convex portion; and
inflating the material within the mold cavity to form the container.
23 . The method of forming a plastic container according to claim 21 , the main body portion further comprising a plurality of cylindrical sidewall portions separated by a corresponding plurality of stiffening grooves, the stiffening grooves extending around the entire circumference of cylindrical main body portion.
24 . The method of forming a plastic container according to claim 21 , the circumferential groove having a concave radius of curvature R 5 and a maximum depth D G , wherein a ratio of R 5 to D G is within a range of 0.20 to 1.0.