Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D51/00—Closures not otherwise provided for
  • B65D51/16—Closures not otherwise provided for with means for venting air or gas
  • B65D51/1672—Closures not otherwise provided for with means for venting air or gas whereby venting occurs by manual actuation of the closure or other element
  • B65D51/1688—Venting occurring during initial closing or opening of the container, by means of a passage for the escape of gas between the closure and the lip of the container mouth, e.g. interrupted threads
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B31/00—Packaging articles or materials under special atmospheric or gaseous conditions; Adding propellants to aerosol containers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D17/00—Rigid or semi-rigid containers specially constructed to be opened by cutting or piercing, or by tearing of frangible members or portions
  • B65D17/06—Integral, or permanently secured, end or side closures
  • B65D17/08—Closures secured by folding or rolling and pressing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D81/18—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient
  • B65D81/20—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas
  • B65D81/2046—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas under superatmospheric pressure
  • B65D81/2053—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas under superatmospheric pressure in an least partially rigid container
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D81/18—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient
  • B65D81/20—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas
  • B65D81/2069—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas in a special atmosphere
  • B65D81/2076—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents providing specific environment for contents, e.g. temperature above or below ambient under vacuum or superatmospheric pressure, or in a special atmosphere, e.g. of inert gas in a special atmosphere in an at least partially rigid container

Definitions

• the present invention relates to a pressurised can and in particular, to an end suitable for use on a pressurised food can.
• a pressurised food can the food product is inserted into the can and stored therein under pressure.
• the increased pressure in the can is achieved by pressurising the headspace above the food product.
• Pressurisation of the headspace may be achieved in a number of different ways.
• a droplet of liquid, inert gas may be inserted into the can prior to sealing with the end, as described in US 289844 (PABST BREWING COMPANY). ⁇ . ).
• the liquid then evaporates and the resultant gas pressurises the headspace.
• a portion of the can may be irreversible pushed inwardly to similarly pressurise the headspace gases by forced reduction of the volume of the headspace. This technique is described in EP 0521642 B (CMB FOODCAN). --. ). Disclosure of Invention
• the advantage of pressurising a can is that the can may be made of substantially thinner gauge metal, which is deformable under normal conditions.
• the internal pressure in the pressurised ca ⁇ supports the walls of the can, providing the rigidity required for handling and transport.
• a can whose contents are held under pressure has the disadvantage that upon first opening, the pressure inside the can is rapidly released to the atmosphere and the stream of released gases may carry a quantity of product.
• This problem is referred to as "spurting” and is highly undesirable for the consumer. In extreme circumstances, such "spurting” may have explosive force making the can dangerous.
• the present invention is concerned with mitigating or even eradicating "spurting", upon first opening of a pressurised can.
• the volume of the headspace (the fee space between the surface of the product and the can) is minimised. This reduces the volume of pressurised gas released from the can upon first opening.
• the inventors have found that the height of the headspace at the point of first opening (i.e. the point at which the can is exposed to atmospheric pressure) needs to be maximised. The height of the headspace at the point of first opening has been found to be critical in deterrmning whether the can will "spurt" when opened by a user.
• Conventional food cans comprise a hollow body, in which the product is stored, and at least one end, which is connected to the free edge of the body, conventionally by seaming and in particular by a technique known as double seaming.
• Conventional ends comprise a flat plate-like centre panel connected to a seaming portion (often referred to as the "cover hook") via a chuck wall, which supports a seaming chuck during the double seaming process.
• a concave reinforcing bead (looking from the outside of the can) is normally provided, to strengthen the end and support the seam.
• Conventional can openers first pierce the can at a point adjacent to or lying within the reinforcing bead. Further shallow beads may also be provided on the wall of the can body and/or on the end, to strengthen the can.
• the invention provides a pressurised can comprising a sealed vessel having an access region at which the sealed vessel is first opened, and a product defining o product surface and a head space, the product confined within the sealed vessel with the headspace arranged in fluid communication with the access region, characterised in that the sealed vessel is adapted to minimise the volume of the headspace, whilst maximising the height of the headspace above the product surface at the access region.
• the volume of the headspace in a can is miriimised because any volume in the can not used for product is wasteful of space and poorly perceived by consumers.
• the volume of the headspace is particularly important, because this "space" contains the pressurised gas, which pressurises the can and has to be released into the atmosphere on first opening of the can.
• the inventors have found that the height of the headspace at the point of first opening is particularly important to the spurting properties of the can and should be maximised to reduce the risk of unacceptable spurting.
• the design of the can will involve a trade-off between minimising the volume of the headspace for the reasons discussed above and maximising the distance between the surface of the product and the point of first opening of the can, to reduce the chances / level of spurting.
• This may be achieved by increasing the height of the headspace within an access region, whilst reducing the height volume of the headspace outside the access region.
• a can is opened using a conventional can opener or where the can end is a so-called “easy-open end” (i.e. EOLE®)
• the can is conventionally opened towards the peripheral edge of the can end.
• the central portion of the end may be indented so that it lies closely adjacent to or even touching the surface of the product. This allows the headspace volume to be minimised whilst ensuring that the height of the headspace at the point of first opening is sufficiently large to prevent or at least significantly reduce the level of spurting.
• the inventors carried out a number of tests using conventional cans having two different types of end (EOLE® - Easy Open End and NEO - Non-easy Open End), different levels of headspace pressurisation and a height of headspace at the point of first opening of 8mm.
• a headspace height of 8mm was chosen as a good average of the headspace height provided in most conventional food cans. All tests were carried at an ambient temperature of 25 °C; the filled cans were allowed to stand for at least V% hour before opening and NEO samples were opened using a Standard Butterfly can opener.
• the level of spurting from the can upon first opening was recorded by holding a sheet of white paper above the end of the can to catch any splatter of product, which was ejected.
• the test is intended to represent the degree of "spurting" that a user would experience, if opening the can whilst wearing white gloves.
• the test is considered successful, if the user could open the can, with no marks damaging the gloves.
• Table 1 The results of the tests are shown in Table 1 (below).
• the meniscus formed on the surface of a the product has been found to make a "meniscus jump" toward such attraction features, even when they are not in contact with the product surface.
• the attraction feature will still draw product away from the access region, increasing the headspace height in this region, providing that it extends far enough towards the product surface to allow the meniscus to make a "meniscus jump” towards it.
• the viscosity and composition of the product will determine the size of gap between the product surface and the attraction feature and therefore the size of "meniscus jump" that the product surface will make.
• the can / end are adapted, so that upon first opening (regardless of the headspace height / volume when the can was filled) the can / end accommodates a volume increase of the headspace and the can does not vent to the atmosphere until the end is lifted a predetermined height above the surface of the product.
• This may be achieved by providing a threaded can / end, in which the thread profile is modified to allow the end to be lifted relative to the can body before finally being unscrewed and the headspace vented to the atmosphere.
• This arrangement has several advantages.
• the can may be filled to conventional fill heights leaving a headspace, which is pressurised. During opening, a user simply unscrews the end.
• FIGURE 1 shows a side section through a conventional food can having a non-easy open end (NOE), identifying the height of the headspace (h) at the point of first opening.
• FIGURE 2 shows a side section through a food can according to the invention having an attraction feature, which touches the surface of the product.
• FIGURE 3 shows an alternative embodiment according to the invention having an attraction feature, which is designed to approach but not touch the surface of the product, illustrating the "meniscus jump" principle.
• FIGURE 4 shows another embodiment according to the invention having an end with a stepped configuration, designed to provide improved strength.
• FIGURE 5 shows an exploded view of another embodiment according to the invention, having a can comprising body and a lid connected together by a modified screw thread and lug arrangement.
• FIGURE 6 shows a side view through of a portion of the can according to FIGURE 5, with the lid on the can body in its closed position (indicating the height of the headspace h).
• FIGURE 7 shows another side view through a portion of the can shown in FIGURES 5 and 6, with the lid on the can body in its partially open position (indicating the increased headspace height h').
• FIGURE 8 shows a magnified view of the screw thread arrangement used in the can according to FIGURES 5 to 7.
• FIGURE 9 shows a side view through a portion of the can according to another embodiment of the invention, with the Ud on the can body in its closed position. In this embodiment, the can has a sUding o-ring style body seal.
• FIGURE 10 shows a side view through a portion of the can shown in FIGURE 9, with the Ud in its partially open, raised position.
• FIGURE 11 shows a side view through a portion of the can according to another embodiment of the invention, with the Ud on the can body in its closed position.
• the sUding seal is provided on the periphery of the Ud.
• FIGURE 12 shows a side view through a portion of the can shown in FIGURE 11, with the Ud in its partially open, raised position.
• a conventional food can 1 has a body 2 and at least one end 3, which is connected to the open end of the body 2 by a seam 4, normally a double seam.
• the food can 1 may either take the form of a 2-piece can, in which the body 2 is produced as a base end and integral side wall or a 3 piece can, in which the side waU takes the form of an open cylinder and separate ends are then seamed on to both ends of the cylindrical side wall.
• a base end is seamed to one of the open ends of the cylinder prior to filling with product 5 and thereafter the second, top end is seamed on to the other end of the cylindrical sidewall.
• the body 2 (comprising the sidewall and base) is filled with a product 5 to a predetermined fill height.
• the product surface 55 will form a meniscus, which is substantially flat. Due to surface tension effects, the product surface 55 will tend to creep up the sidewall of the body 2 to a point 52, where the product surface 55 adjoins the sidewall of the body 2.
• the free space between the product surface 55 and the end 3 is referred to as the headspace 7 and is filled with gas (normally air or an inert gas). In a pressurised food can, it is this headspace 7, which is pressurised.
• the invention teaches that the headspace height h between the point of first opening (i.e. the point at which the tin opener first pierces the can) and the product surface 55 needs to be as large as possible, if "spurting" is to be avoided.
• a large headspace volume is undesirable in a pressurised food can because a large headspace volume necessitates venting of a larger volume of gas before the pressure in the can reaches atmospheric pressure.
• a large headspace 7 is also perceived badly by consumers, who feel cheated by the fact that the can 1 is not as full as originally perceived. Thus, a compromise has to be reached between maximising the height h of the headspace 7, whilst controlUng the overall volume of the headspace 7 in the can 1.
• a food can 1 may also have a body 2, end 3, seam 4 and reinforcing bead 6 configuration as described above.
• the can 1 is additionally provided with one or more attraction features 11, which draw the product 5 away from the point of first opening (at the base of the reinforcing bead 6), thereby mamtaining a clear headspace height h at this point.
• the attraction feature 11 comprises an indentation, which is sized and positioned such that it touches the surface 55 of the product 5.
• the product surface 55 is attracted to the attraction feature 11, by surface tension forces, thereby forming a meniscus with attraction points 51 and 52.
• the indentation also has the benefit that it reduces the overall volume of the headspace 7, reducing the volume of pressurised gas that is vented when the can 1 is first opened.
• FIG 3 illustrates another embodiment of the invention, to which the principle of an attraction feature 11 has been appUed.
• the food can 1 comprises a body 2 and an end 3, sealed together by a double seam 4.
• the can has a reinforcing bead 6 and many conventional designs of tin opener are designed to first pierce the food can 1 at the base of this bead 6.
• the can 1 is filled with a product 5 to a predetermined height.
• a portion of the can end 3, spaced radially inwardly of the reinforcing bead 6 is indented inwardly by a distance sufficient to approach closely but not touch the surface of the product 5.
• the attraction feature 11 does not touch the surface 55 of the product 5, but approaches sufficiently closely that the attraction of the product surface 55 to the attraction feature 11 causes the product surface 55 to make a "meniscus jump" 50, bridging the gap between the product surface 55 and the lowest point of the attraction feature 11.
• This meniscus jump 50 draws an even greater volume of product 5 away from the point of first opening 6, ensuring that the headspace 7 is unobstructed at this point.
• FIG 4 illustrates another embodiment of a pressurised food can 1 to which this principle has been appUed.
• the food can 1 comprises a body 2 and an end 3, sealed together by a double seam 4. Again the end has a reinforcing bead 6 and an indentation spaced radially inwardly thereof, which acts as an attraction feature 11.
• the attraction feature 11 is formed by a series of indentations (beads) in the can end (3), which approximates the shape of a curve C. It is known from the manufacture of pressure vessels that a domed shape (either concave or convex) has the greatest strength for resisting pressure. Formation of a stable dome is difficult when using thin metal (as is the case in the manufacture of food cans).
• Figures 5 to 8 show a further embodiment of the invention, which is adapted to mitigate the effect of "spurting" when the can 1 is first opened.
• the product fill height is less critical because the opening arrangement is designed to Uft the end 3 relative to the body 2 before the can is allowed to vent for the first time.
• the opening arrangement is designed to Uft the end 3 relative to the body 2 before the can is allowed to vent for the first time.
• the internal volume of the can 1 is increased and thereby, the internal pressure is reduced (as shown in Figures 6 and 7).
• the necessary height of the headspace at the point of first opening h' is created during the opening process (see Fig. 7).
• the can 1 may comprise a body 2 and a Ud 3 connected together by a screw thread arrangement.
• the screw thread arrangement is modified, such that the Ud 3 can Uft a specified distance during unscrewing. This increases the internal volume of the can and thereby reduces the internal pressure thereof, without venting the gases in the headspace 7.
• the modified thread arrangement takes the form of a lug 43 carried on either one of the body 2 or Ud 3 and one or more threads 42 carried on the other of the body 2 or the Ud 3.
• the lug 43 is shown carried on the Ud 3 and a pluraUty of threads 42 are shown defined on the body 2.
• the thread 42 takes a "z-shaped" form having two thread portions 421 interconnected by a vertical Uft portion 422.
• the two thread portions 421 serve the same purpose as a conventional screw thread and the Uft portion 422 is the substantially vertical portion of the thread 42, which allows the Ud 3 to be Ufted relative to the body 2, without venting the container.
• the vertical Uft portion 422 may not be exactly vertical, but actually steeply sloped. The reason for this is that a vertical portion 422 would provide the desired Uft, but the end 3 would tend to rise with a jolt, giving a shock to the user opening the container. Furthermore, this shock may result in displacement of the lug 43 from the thread 42. If the lug 43 is displaced from the thread 42, the Ud 3 may be fired off the container with sufficient force to harm the user.
• the terminal ends of the thread portion 42 are shaped to provide a retaining feature 425.
• the retaining feature 425 retains the lug 43 and prevents over tightening of the Ud 3 as it is screwed onto the body 2.
• the retaining feature 425 holds the lug 43 on the screw thread 42 and prevents the Ud from being ejected from the container, prior to venting of the internal gases from the container.
• a seal is formed between the body 2 and Ud 3 of the can using sealing compound 8.
• the sealing compound 8 forms a face seal 84 between the Ud 3 and body 2 of the can.
• the lugs 43 rise up the slope on the thread 42 very quickly, before stopping at the retaining feature 425.
• the compound face seal 85 is broken, but as the volume expansion of the can occurs very quickly, the internal pressure is reduced before venting can occur. This effect greatly reduces the quantity of product 5 entrained in the subsequently venting gases.
• FIGURES 9 and 10 show an alternative embodiment of a screw can according to the invention.
• the thread / lug arrangement is the same as that shown in Figures 5 to 8.
• the Ud has a flared portion 35, which is of wider diameter than the remainder of the Ud 3.
• the seal between the body 2 and Ud 3 of the can is provided by a sUding body seal 85, which extends around the periphery of the open end of the body 2, The sUding body seal 85 prevents the can from venting until the lug 43 reaches the "open" end of the thread 42 and the Ud 3 is Ufted to the point at which the flared portion 35 passes the open end of the body 2. At this point any residual pressure in the can (remaining after the volume expansion caused by the Ufting of the Ud 2) may be vented to the atmosphere (as indicated by the arrows in FIGURE 10).
• FIGURES 11 and 12 show another embodiment of a screw can according to the invention.
• the thread / lug arrangement is the same as that shown in Figures 5 to 10 and the Ud has a flared portion 35, which is of wider diameter than the remainder of the Ud 3 (as shown n Figures 9 and 10).
• a sUding Ud seal 86 is provided to seal the body 2 and Ud 3 of the can during opening.
• the sUding Ud seal 86 is formed by inserting sealing compound around the inside of a portion of the top wall and sidewall of the Ud 3 and prevents the can from venting until the lug 43 reaches the "open" end of the thread 42 and the Ud 3 is Ufted to the point at which the flared portion 35 passes the open end of the can body 2. At this point any residual pressure in the can (remaining after the volume expansion caused by the Ufting of the Ud 2) may be vented to the atmosphere (as indicated by the arrows in FIGURE 12).
• the flared portion on the Ud may be replaced by a tapered section of the open end of the body.
• the thread arrangement may comprise an internal thread on the can body and the Ud may take the form of a stopper.
• the flared section may be provided at the open end of the body, rather than on the cover.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Closures For Containers (AREA)
• Vacuum Packaging (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Rigid Containers With Two Or More Constituent Elements (AREA)
• Diaphragms For Electromechanical Transducers (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (8)

Citations (5)

Family Cites Families (5)

• 2004
  • 2004-10-22 AT AT04817277T patent/ATE388908T1/de not_active IP Right Cessation
  • 2004-10-22 WO PCT/EP2004/052624 patent/WO2005040006A1/en active IP Right Grant
  • 2004-10-22 ES ES04817277T patent/ES2303137T3/es active Active
  • 2004-10-22 EP EP04817277A patent/EP1678055B1/de active Active
  • 2004-10-22 CA CA002544141A patent/CA2544141A1/en not_active Abandoned
  • 2004-10-22 US US10/576,538 patent/US20070071856A1/en not_active Abandoned
  • 2004-10-22 JP JP2006537286A patent/JP2007509823A/ja not_active Abandoned
  • 2004-10-22 DE DE602004012434T patent/DE602004012434T2/de active Active

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