US20040195199A1

US20040195199A1 - Hot fill container

Info

Publication number: US20040195199A1
Application number: US10/406,323
Authority: US
Inventors: Kirk Maki; John Daly
Original assignee: GRAFCO PET TECHNOLOGIES
Current assignee: GRAFCO PET TECHNOLOGIES
Priority date: 2003-04-04
Filing date: 2003-04-04
Publication date: 2004-10-07

Abstract

A hot fill container is provided having a base, a body portion connected to the base, a shoulder portion connected to the body portion, and a neck portion connected to the shoulder portion. At least two panels in the shoulder portion are adapted to flex to accommodate pressure changes within the hot fill container. A longitudinal strut between each of the at least two panels provides longitudinal support to the neck portion.

Description

FIELD OF THE INVENTION

The present invention relates to a container used for products introduced into the container while warm or hot, as appropriate, for sanitary packaging of the product. More particularly, the present invention relates to a non-rigid “hot fill” container having flexible panels or windows recessed into the shoulder of the container and having longitudinal struts separating adjacent panels. The panels are adapted to flex to accommodate pressure changes within the “hot fill” container associated with temperature changes of the product within. The struts allow the desired panel flexure but prevent excessive and deforming changes that would compromise container strength and adequate label attachment surfaces.

BACKGROUND OF THE INVENTION

Non-rigid containers used for filling processes with warm or hot products, so called “hot fill applications”, must address several fundamental concerns that are not present in conventional container applications. A primary concern arises because liquid food products must be poured and sealed in a container at an elevated temperature that is high enough to destroy bacteria, microorganisms and the like to sustain food quality. The thin side walls of conventional non-rigid containers thermally distort or collapse at “hot fill” temperatures. Assuming that a non-rigid container can be formed in a configuration that maintains its shape at the “hot fill” temperature, i.e. “thermally stable”, the container is then subjected to a vacuum that is inherently drawn within the sealed or capped container when hot food products cool and contract. The non-rigid container must either withstand the vacuum or collapse with sufficient deformation to accommodate the vacuum. Therefore, rigid containers, such as glass, have traditionally been used in “hot fill applications”. A need exists for a non-rigid container that withstands the pressure changes associated with “hot fill applications”.

Another concern in “hot fill applications” using non-rigid containers is body deformation that impacts container labeling. Existing non-rigid container configurations substantially retain their overall shape, but the bottles flex their side wall. This in turn requires special labels and/or labeling techniques to be used by the bottler. In typical glass bottling operations, a light weight paper label is simply glued onto the bottle as it is rolled after the bottle is hot filled and capped. The non-rigid side wall configurations of existing non-rigid “hot fill” containers flex and will not hold conventional, glued light weight paper labels, especially when the vacuum seal is broken and the bottle expands. A need exists for a non-rigid container that withstands the pressure changes associated with “hot fill applications” without flexing of the side walls.

U.S. Pat. No. 3,403,804 to Colombo discloses a blown bottle of flexible plastic having a plurality of spaced pairs of grooves 16′ around the circumference of the body portion, as shown in FIG. 1. The grooves resist radial swelling of the container in the body portion due to internal gas pressure. However, the container is not able to prevent axial or longitudinal deformation of the container in the neck portion.

U.S. Pat. No. 3,397,724 to Bolen et al. discloses a thin walled container that is prebulged to avoid bulging of the container when filled and allowed to stand, as shown in FIG. 2. Moreover, slight additional radial deformation of the container is permitted. The container does not eliminate radial and longitudinal deformation of the container in either the body or neck portions.

U.S. Pat. No. 3,297,194 to Schaper et al. discloses a container having a plurality of circumferentially extending ribs 28 around the mid-section of side wall 14, as shown in FIG. 2, to prevent the container from becoming out of round. However, the ribs allow the container to be compressed during axial loading, and return the container to its original height when the axial load is removed.

Another concern in “hot fill applications” is that of longitudinal force loadings on the non-rigid container. Existing bottling operations typically employ star wheel layouts. Non-rigid containers are filled in one wheel and transferred to another wheel having a capper that screws the closure onto the non-rigid container while the wheel rotates at high speed. The hot fill product is still hot when the capping mechanism tightens the closure. The ability of the non-rigid material to withstand compressive forces is reduced at elevated temperatures. While the capper mechanism can be and has been altered to reduce longitudinal force loadings on non-rigid containers and/or non-rigid containers have been altered to provide mouth rings for loading purposes, such factors affect the bottle configuration. Non-rigid containers must have a side wall strength sufficient to permit stacking one on top of the other without collapse. Existing non-rigid containers having vacuum panels indented into the side wall do not assist the container in developing sufficient longitudinal strength to resist deformation. Moreover, vacuum panels in the neck portion of the non-rigid container do not prevent changes in the height of the overall container due to longitudinal deformation of the vacuum panels in the neck portion of the container. A need exists for a hot fill container that has sufficient strength to resist longitudinal deformation due to longitudinal loading and deformation caused by the vacuum associated with “hot fill applications”.

U.S. Design Pat. Nos. D225,510 to Strand; D218,020 to Musson; D219,129 to Wood; D195,371 to Torongo; D294,462 to Ota et al.; D295,499 to LeFevre; D278,682 to Khalifa; and D70,732 to Dengler et al. disclose containers having panels in the neck portion. However, none of the patents disclose means to prevent longitudinal deformation of the containers due to longitudinal loading and deformation caused by the vacuum associated with “hot fill applications”.

U.S. Pat. No. 5,067,622 to Garver et al. discloses a container 70 having vacuum panels 83 recessed in the neck segment 81, as shown in FIG. 4, that deflect radially when a vacuum is drawn in the container. The panels 83 in combination with the bulbous neck segment 81 prevent both radial and longitudinal contraction of the body portion 77 of the container. However, nothing prevents longitudinal contraction of the neck segment 81 when a vacuum is drawn in the container.

A need exists for a non-rigid hot fill container that does not lose its shape or height due to pressure changes associated with hot fill applications of non-rigid containers.

SUMMARY OF THE INVENTION

Accordingly, it is a primary objective of the present invention to provide a non-rigid container for products filled while warm or hot wherein the container resists deformation due to pressure increases or reductions as the “hot fill” product cools or is heated.

Another objective of the present invention is to provide a non-rigid container for hot fill applications that resists flexing of the container side walls due to pressure changes within the container associated with hot fill applications.

Another objective of the present invention is to provide a non-rigid container for hot fill applications that resists longitudinal deformation due to pressure changes within the container associated with hot fill applications.

The foregoing objects are basically attained by providing a non-rigid hot fill container having a base, a body portion connected to the base, a shoulder portion connected to the body portion, and a neck portion connected to the shoulder portion. At least two panels in the shoulder portion are adapted to flex to accommodate pressure changes within the hot fill container. A longitudinal strut between each of the at least two panels provides longitudinal support to the neck portion.

Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings that form a part of the original disclosure: [0016]
FIG. 1 is a perspective view of a non-rigid hot fill container according to the present invention; [0017]
FIG. 2 is a perspective view of the container of FIG. 1 showing the base of the hot fill container; [0018]
FIG. 3 is a front elevation view of the container of FIG. 1; [0019]
FIG. 4 is a top view of the container of FIG. 1; [0020]
FIG. 5 is a bottom view of the container of FIG. 1; [0021]
FIG. 6 is an enlarged front elevation view of the panels and struts of the container of FIG. 1 and without a cap on the neck portion of the container; [0022]
FIGS. 7-9 are diagrams showing flexing of the panels of the present invention between the initial temperature at which the hot fill product is introduced to the non-rigid hot fill container and the final temperature at which the product has cooled.[0023]

DETAILED DESCRIPTION OF THE INVENTION

As seen in FIGS. 1-9, the non-rigid [0024] hot fill container 21 of the present invention has a base 31, a body portion 41 connected to the base, a shoulder portion 51 connected to the body portion, and a neck portion 61 connected to the shoulder portion. At least two panels 71 recessed into the shoulder portion are adapted to flex to accommodate pressure changes within the non-rigid hot fill container 21 associated with hot fill applications. A longitudinal 81 strut between each of the at least two panels 71 provides longitudinal support to the shoulder portion 51 and the neck portion 61.
The [0025] base 31 provides support for the container 21. Preferably, as shown in FIGS. 2 and 5, the base is substantially circular. The base 31 has a substantially planar portion 33 providing support for the container. A concave portion 35 has a plurality of ribs 37 to provide lateral and longitudinal strength to the container. As shown in FIGS. 2 and 5, the concave portion 35 preferably has six ribs 37.
A [0026] body portion 41 extends upwardly from an outer edge 29 of the base 31 to an upper lip 46 of the body portion. The body portion 41 is substantially perpendicular to the base. The body portion 41 includes a plurality of flat portions 43, as shown in FIG. 3. A ribbed portion 45 separates each flat portion. Each flat portion 43 has a width “f”, as shown in FIG. 3. Each ribbed portion 45 has a width “r”, as shown in FIG. 3. Preferably, the width “f” of each flat portion is twice the width “r” of each ribbed portion. Flat portions 43 having a width larger than the width of the ribbed portions 45 provides a body portion having a larger surface area, which allows for better label adhesion. Additionally, the smaller width of the ribs prevents label distortion when the container 21 is handled after the label has been affixed to the container. Preferably, the label is affixed over the width “l” on the body portion 41, which is denoted by lines 42 and 44 of FIG. 3. The ribs 43 also prevent radial deformation of the body portion 41 of the container due to pressure changes in the container associated with hot fill applications, e.g., the hoop stress induced in the body portion due to the vacuum caused by the temperature drop of the hot fill product.
A [0027] shoulder portion 51 extends upwardly from the upper lip 46 of the body portion 41 of the container 21, as shown in FIGS. 3 and 6. Preferably, the shoulder portion 51 tapers inwardly as it extends upwardly from the body portion 41, thereby forming a frustoconical configuration. The degree of taper θ may be between 0 and 89 degrees, inclusive, as shown in FIG. 6. A plurality of flex panels 71 are positioned around the circumference of and recessed into the shoulder portion 51. Each flex panel 71 is separated from the adjacent flex panel by a longitudinal strut 81. The flex panels 71 and longitudinal struts 81 extend upwardly from the upper lip 46 of the body portion 41 to the curved lip 53 of the shoulder portion 51. The curved lip 53 is substantially C-shaped and extends outwardly from the longitudinal axis 23 of the container 21 before extending inwardly to meet the bottom edge 63 of the neck portion 61.
The [0028] flex panels 71 have an upper width “UW” and a lower width “LW”, as shown in FIG. 6. Preferably, the upper width and the lower width of the flex panels 71 are not equal, as shown in FIG. 6. The initial configuration of the flex panels 71 has a convex curvature, as shown in FIGS. 6 and 7. The flex panel 71 has a radius from the longitudinal axis that is greater at the middle 73 than at the upper and lower end points 75 and 77, respectively, as shown in FIG. 7. The dashed line 79 shown in FIGS. 7-9 corresponds to a line between the upper end point 75 and the lower end point 77 of the flex panel 71 that is parallel to the taper θ of the shoulder portion 51, i.e., a flat panel. Preferably, there are between four and six flex panels 71 around the circumference of the shoulder portion 51. Preferably, the edge 72 of the flex panel 71 may have an initial concave curve 74 before curving convexly 76 at the center of the panel to provide greater flexibility. The flex panels 71 may be symmetrically or asymmetrically space around the circumference of the shoulder portion 51.
The longitudinal struts [0029] 81 extend from the upper lip 46 of the body portion to the curved lip 53 of the shoulder portion 51, as shown in FIGS. 1, 3 and 6. The longitudinal struts 81 separate each of the flex panels 71 and allow the panels to flex independently of the struts. Preferably, there are an equal number of struts and flex panels around the circumference of the shoulder portion, i.e., four-six struts. The longitudinal struts 81 resist longitudinal loading (vertical compression) introduced by the capping and sealing process. Furthermore, the longitudinal struts 81 maintain the height of the container 21 by preventing longitudinal and lateral movement of the shoulder portion 51 when the flex panels 71 flex to accommodate internal pressure changes associated with hot fill applications.
Preferably, the strut height “SH” is approximately equal to 105-125% of the panel height “PH”, as shown in FIG. 6. Preferably, the strut width “SW” is approximately equal to 5-100% of the panel lower width “LW”. More preferably the strut width is approximately 5-25% of the panel lower width. Preferably, the upper width “UW” of the [0030] flex panel 71 is approximately equal to 90% of the lower width “LW”. Preferably, the lower width “LW” is approximately 110% of the panel height “PH”.
A [0031] neck portion 61 extends upwardly from edge 63 of the neck portion 61 to the top edge 64 of the neck portion, as shown in FIGS. 3 and 6. The neck portion 61 has an outer surface 65 that has external threads 67, as shown in FIG. 6. The neck portion 61 has an opening 68 for introducing hot fill product into the container. Preferably, the diameter of the opening 68 is at least 38 mm, but it may be any diameter suitable for the hot fill application. The step-down recess from the shoulder portion 51 into the perimeter of the neck portion 61 maintains the strength of the neck portion, as shown in FIG. 3.
A [0032] cap 69 has internal threads for threading onto neck portion 61 of the container 21 to seal the hot fill product within the container. A neck shoulder 66 provides a stop for the cap 69.
Assembly and Operation [0033]
Preferably, the [0034] base 31, body portion 41, shoulder portion 51, neck portion 61, panels 71 and struts 81 are unitarily formed. The hot fill container 21 is made of a non-rigid material, preferably PET (polyethylene terephtlate).
Typically, during hot fill applications, a hot fill product is introduced into the [0035] container 21 at an initial temperature (To) of approximately 185 degrees Fahrenheit (85 degrees Celsius). Once the container has been filled with the hot fill product to a predetermined level, a cap 69 is secured to the container 21, preferably by threading the cap onto the externally threaded neck portion, to seal the hot fill product within the container. The initial configuration of the flex panels 71 when the container is sealed at T_Ois shown in FIG. 7.
As the temperature of the hot fill product begins to cool, the pressure in the headspace above the liquid within the [0036] container 21 begins to drop. As the temperature of the hot fill product continues to drop toward ambient temperature, the air pressure within the container 21 also continues to decrease. To offset the pressure drop within the container 21, the panels 71 begin to flex inwardly to accommodate the pressure drop, as shown in FIGS. 8 and 9. As shown in FIG. 8 at an intermediate temperature (T₁) of approximately 110 degrees Fahrenheit (43 degrees Celsius), the panels 71 have flexed inwardly slightly, thereby approaching being a planar flex panel as indicated by dashed line 79. As shown in FIG. 9, when the temperature of the hot fill product has finished dropping and reached ambient temperature, a final temperature T_Fof approximately 72 degrees Fahrenheit (22 degrees Celsius), the panels 71 have finished flexing to accommodate the pressure drop within the container. At the final temperature, T_F, the panels 71 have flexed such that there is now a concave curvature at a midpoint 73 of the panel, as shown in FIG. 9. The panels 71 have moved beyond the planar surface indicated by dashed line 79 to accommodate the pressure drop within the container 21 and to maintain the overall shape of the container. Furthermore, the flexing of the panels 71 to accommodate the pressure drop prevents deformation of the body portion 41 of the container so that label affixed to the body portion remains unaffected.
The longitudinal struts [0037] 81 prevent longitudinal flexing of the panels 71 during the cooling of the hot fill product, thereby ensuring that the overall height of the container 21 remains unchanged. This facilitates stacking of the containers since the top surface 62 of the cap 69 remains parallel to the planar surface 33 of the base 31. Moreover, the longitudinal struts 81 provide longitudinal strength to the container 21 to prevent buckling of the container during the capping process.
While advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined in the appended claims. [0038]

Claims

What is claimed is:

1. A hot fill container, comprising:

a base;

a body portion connected to said base and extending longitudinally therefrom;

a shoulder portion connected to said body portion;

a neck portion connected to said shoulder portion;

at least two panels in said shoulder portion adapted to flex to accommodate pressure changes within said hot fill container; and

a longitudinal strut between each of said at least two panels to prevent longitudinal flexing of said at least two panels.

2. A hot fill container according to claim 1, wherein

said body portion has a plurality of flat portions.

3. A hot fill container according to claim 2, wherein

said plurality of flat portions are separated by ribbed portions.

4. A hot fill container according to claim 3, wherein

each of said ribbed portions has a first width, each of said plurality of flat portions has a second width, and said first width is substantially one half said second width.

5. A hot fill container according to claim 1, wherein

said neck portion has a diameter of at least 38 millimeters.

6. A hot fill container according to claim 1, wherein

each of said at least two panels has a first edge having a first width and a second and opposite edge having a second width, said first and second widths not being equal.

7. A hot fill container according to claim 1, wherein

said shoulder portion is tapered.

8. A hot fill container according to claim 7, wherein

said taper has an angle between 1 and 89 degrees, inclusive.

9. A hot fill container according to claim 1, wherein

said base is circular.

10. A hot fill container according to claim 1, wherein

said neck portion is threaded for receiving a cap.

11. A hot fill container according to claim 1, wherein

said at least two panels comprises between four and six panels, inclusive.

12. A hot fill container according to claim 1, wherein

said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are unitarily formed.

13. A hot fill container according to claim 1, wherein

said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are made of PET.

14. A hot fill container according to claim 1, wherein

said at least two panels are substantially rectangular.

15. A hot fill container according to claim 14, wherein

said at least two panels have a concave curve at an edge and a convex curve at a center of said at least two panels.

16. A hot fill container, comprising:

a base;

a body portion connected to said base, said body portion having a plurality of flat portions and a ribbed portion separating each of said flat portions;

a tapered shoulder portion connected to said body portion;

a neck portion connected to said shoulder portion, said neck portion having a threaded external surface to receive a cap;

a longitudinal strut between each of said at least two panels to prevent longitudinal flexing of said at least two panels,

wherein said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are unitarily formed.

17. A hot fill container according to claim 16, wherein

said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are made of PET

18. A hot fill container according to claim 16, wherein

each of said ribbed portions has a first width, each of said plurality of flat portions has a second width, and said first width is one half said second width.

19. A hot fill container according to claim 16, wherein

said neck portion has a diameter of at least 38 millimeters.

20. A hot fill container according to claim 16, wherein

each of said at least two panels has a first edge having a first length and a second and opposite edge having a second length, said first and second lengths not being equal.

21. A hot fill container according to claim 16, wherein

said tapered shoulder portion has an angle between 1 and 89 degrees, inclusive.

22. A hot fill container according to claim 16, wherein

said base is circular.

23. A hot fill container according to claim 16, wherein

said at least two panels comprises between four and six panels, inclusive

24. A hot fill container according to claim 16, wherein

said at least two panels are substantially rectangular.

25. A hot fill container according to claim 14, wherein