EP0048890B1 - Lightweight container - Google Patents
Lightweight container Download PDFInfo
- Publication number
- EP0048890B1 EP0048890B1 EP19810107280 EP81107280A EP0048890B1 EP 0048890 B1 EP0048890 B1 EP 0048890B1 EP 19810107280 EP19810107280 EP 19810107280 EP 81107280 A EP81107280 A EP 81107280A EP 0048890 B1 EP0048890 B1 EP 0048890B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- metal container
- container according
- dome
- lip
- adhesive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000000853 adhesive Substances 0.000 claims description 60
- 230000001070 adhesive effect Effects 0.000 claims description 60
- 229910052751 metal Inorganic materials 0.000 claims description 38
- 239000002184 metal Substances 0.000 claims description 38
- 229910052782 aluminium Inorganic materials 0.000 claims description 19
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 19
- 239000012790 adhesive layer Substances 0.000 claims description 14
- 229910000831 Steel Inorganic materials 0.000 claims description 12
- 239000010959 steel Substances 0.000 claims description 12
- 230000006835 compression Effects 0.000 claims description 10
- 238000007906 compression Methods 0.000 claims description 10
- 230000004323 axial length Effects 0.000 claims description 5
- 238000011068 loading method Methods 0.000 description 13
- 238000012360 testing method Methods 0.000 description 9
- 239000000956 alloy Substances 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 7
- 238000013461 design Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 235000013361 beverage Nutrition 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 230000007704 transition Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000994 depressogenic effect Effects 0.000 description 2
- 230000001066 destructive effect Effects 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229920001944 Plastisol Polymers 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000037237 body shape Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000002788 crimping Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000004999 plastisol Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 238000004826 seaming Methods 0.000 description 1
- 230000011218 segmentation Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D51/00—Making hollow objects
- B21D51/16—Making hollow objects characterised by the use of the objects
- B21D51/26—Making hollow objects characterised by the use of the objects cans or tins; Closing same in a permanent manner
- B21D51/2684—Cans or tins having circumferential side seams
-
- 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
- B65D39/00—Closures arranged within necks or pouring openings or in discharge apertures, e.g. stoppers
- B65D39/16—Closures arranged within necks or pouring openings or in discharge apertures, e.g. stoppers with handles or other special means facilitating manual actuation
-
- 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
- B65D47/00—Closures with filling and discharging, or with discharging, devices
- B65D47/04—Closures with discharging devices other than pumps
- B65D47/06—Closures with discharging devices other than pumps with pouring spouts or tubes; with discharge nozzles or passages
- B65D47/12—Closures with discharging devices other than pumps with pouring spouts or tubes; with discharge nozzles or passages having removable closures
- B65D47/14—Closures with discharging devices other than pumps with pouring spouts or tubes; with discharge nozzles or passages having removable closures and closure-retaining means
- B65D47/141—Closures with discharging devices other than pumps with pouring spouts or tubes; with discharge nozzles or passages having removable closures and closure-retaining means for stoppers
-
- 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
- B65D7/00—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal
- B65D7/12—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal characterised by wall construction or by connections between walls
- B65D7/34—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal characterised by wall construction or by connections between walls with permanent connections between walls
- B65D7/38—Containers having bodies formed by interconnecting or uniting two or more rigid, or substantially rigid, components made wholly or mainly of metal characterised by wall construction or by connections between walls with permanent connections between walls formed by soldering, welding, or otherwise uniting opposed surfaces
Definitions
- This invention relates to lightweight metal containers such as may be used to contain a beverage.
- Containers of the general type under consideration are primarily made of aluminum and have a cylindrical body with an integral bottom.
- the top is usually closed by a generally flat end member of different alloy than the body which is usually H 19-3004.
- the present commercial aluminum containers including ends weigh approximately 0.018-0.020 kg (0.040-0.045 pounds) each.
- the single service beverage cans of the 1960's includes a three-piece steel body, steel bottom and an aluminum top.
- the most popular can of the 1970's was an all aluminum drawn and wall-ironed can with a double seamed top.
- the top was of a different alloy than the can body.
- Aluminum because of its light weight and ductility and being able to be easily cast, is finding growing uses, most recently in the automotive industry. Material costs are rapidly escalating and the supply is dwindling. Various structures have been made to shape the bottom of the can to obtain more volume with less strength. Inverted or concave bottoms were provided on the 1970 vintage cans to resist the pressure of the contents, however, this design is wasteful of the material in that a taller than necessary can must be provided necessitating additional material to obtain the desired volume. Furthermore, the flat top end on such cans requires the use of a strong alloy aluminum material having a magnesium content. The compositions of the body and that of the end of each can, being different, complicates recycling of the cans.
- steel cans on the other hand, because of the thickness of the metal used, require high tonnage presses and tools must be more frequently replaced. When thick metal is used, the costs and carrying weights become excessive. In order to obtain an easy opening feature, steel cans invariably use aluminum tops which complicates recycling. The aluminum and the steel must be separated which is a time consuming costly process. The attractiveness of steel for cans is the lower cost of the metal and its great availablity.
- U.S.-A-2,197,434 relates to a metal container comprising a body, a top including a lower cylindrical lip and a conical inner and upper portion, the upper portion of the body and the cylindrical lip of the top forming a lapped joint.
- the object of this invention is to provide a metal container which uses less material but retains the strength characteristics of the present containers.
- the present invention provides a metal container comprising a body, a top including a lower cylindrical lip and a conical inner and upper portion, the upper portion of said body and said cylindrical lip of said top forming a lapped joint, characterized in that the adhesive layer is provided between said body and said top at said lapped joint, said container top comprises a dome in which said lip merges at its upper edge into a toroidal curve which merges into said conical inner and upper portion and wherein under internal pressure said conical portion is deformed generally axially upward and said toroidal curve is deformed generally radially inwardly with said lip being tilted radially inwardly to compress at least an upper part of said adhesive layer.
- the concave bottoms of the principal current designs 0.0355 cm (0.014 inch) thick are replaced on the can of this invention formed of aluminum by a convex bottom about 0.0203 cm (0.008 inch) thick which results in a container of increased volume using less aluminum.
- the double seam of the current containers which also consumes aluminum is eliminated by substituting an adhesive telescoped joint.
- the top or dome of the new container may be about 0.229 mm (about 9 mils) thick compared to the double seam flat top of 0.356 mm (about 14 mils) thickness of the current containers.
- the heavy flange thickness 0.178 mm (about 7 mils) of double seamed cans is not required and is reduced to 0.102 mm (4 mils).
- a total package weight of about 9.07 kg (20 pounds) per one thousand cans is obtained versus 17.23-18.14 kg (38-40 pounds) per one thousand cans of the present lightest weight aluminum cans.
- the two pieces of the new can are assembled at the can plant and later filled through the small drink hole using conventional bottle fillers.
- steel cans 0.051-0.0635 mm (2 to 2-1/2 mils) in wall thickness are feasible.
- the elimination of a special alloy for the can ends by making the can of one alloy produces a uni-alloy can, therefore making it more valueable as scrap for recycling.
- the improved can remains cleaner, has better pourability and can be reclosed and resealed.
- the new container provides a top which increases container volume and can be as easily used for 0.47 I (16 ounce) cans as well as for 0.35 I (12 ounce) cans or even 0.28 I (10 ounce) cans merely by lengthening or shortening the can body.
- a further feature of the new container is that it can be made on present existing equipment without excessive capital investment.
- Advantage is taken of the shape of the top and of the thinness of about 0.022 cm (0.009 inch) and short axial length of the top with respect to the body length of the container to which the top is applied by shaping the top in a manner such that on filling the container with pressurized beverage internal pressure forces are exerted on the cone section of the top to cause beamloading of the cone section to exert inward forces on the lip at the base of the cone portion to assist the adhesive by applying compressive forces thereagainst and to the portion of the opposing body portion at the telescoped junction of the body and top. Peeling forces on the adhesive in the bonded telescoped junction as would ordinarily occur under internal pressure loading are thus eliminated.
- Various configurations of the top portion are shown which obtain specific benefits as hereinafter defined.
- the body In 0.35 I (12 ounce) cans, the body has a diameter of 6.60 cm (2.60 inches) and an axial length of 10.16 cm (4 inches) whereas in the 0.47 I (16 ounce) can the body length or height is 12.06 cm (4.75 inches).
- the toroidal section which provides the transition between the sloping conical section and the axial lip section, is arcuate in cross section and has a radius of 0.158 to 0.635 cm (1/16 to 1/4 inch). It has been found that as the material used becomes thinner, the radius must be made larger. If the beaming forces were to be restricted or with a sharp angle at the juncture, the conical portion would buckle and wrinkle adjacent to the lip.
- the invention comprehends providing a transition between the cone and the lip such that internal pressure forces tending to expand the conical section as well as the toroidal portion are utilized to produce a compressive force radially inwardly on the adhesive which together with the tensile forces tending to expand the upper end of the body portion ensures parallelism between opposing body and lip portions and thus precludes developing voids such as would produce leaking joints.
- the invention comprehends making an adhesively bonded joint as an extremely narrow axial band on the order of 0.158 to 0.317 cm (1/16 to 1/8 inch) which is now feasible because of the compressive loading on the adhesive.
- the wall thickness of both the top and bottom sections of the can would be on the order of 2 to 2-1/2 mils thick or 0.30 mm (.0118 inch) thick.
- FIG. 1-5 of the drawings An embodiment of the invention is shown in Figures 1-5 of the drawings as comprising a container, generally designated 1, preferably entirely formed of one alloy of aluminum such as H19-3004.
- the container has a lower or bottom portion 2 and a top portion or dome 3.
- the lower portion 2 comprises a bottom 4 and an integral cylindrical body 6 which at its upper end 8 is necked-in to provide a radially inwardly extending shoulder 10 about 0.0793 to 0.158 cm (1/32 to 1/16 inch) wide and about the inner edge of which there is an axially extending annulus or ring 12 of approximately 0.317 cm (1/8 inch) in length.
- the annulus or ring 12 preferably has a tight or interference fit into the lower end of an annular band or lip 14 of the dome 3 which is of an axial length corresponding to that of the ring 12 while the dome 3 is about 2.12 cm (.837 inch) in total axial height.
- the upper edge of the lip 14 merges into the lower edge of a toroidal or arcuate transition section 15 which at its upper edge merges into the lower edge of a conical section 16.
- the section 15 has a radius of between 0.158 to 0.635 cm (1/16 to 1/4 inch) preferably the thinner the metal, the greater the radius.
- the conical section 16 shown in Figures 1 and 5 is preferably of a stepped design and comprises a frustoconical annular band 18 which merges at its lower edge with the upper edge of the toroidal section 15 and the upper edge of the band 18 merges with the lower edge of a conical segment 20 which at its upper edge, in turn, merges into the lower edge of a second smallerfrustoconical band 22.
- the band 22 has its upper edge merging into the lower edge of a second frustoconical segment 24 which, at its upper edge, merges into a curl 25 which is turned outwardly over the second segment 24.
- the lower edge of the lip 14 is provided with an outturned downwardly flaring frustoconical or curled flange 26 which has an outer edge substantially coaxial with an external circular surface 30 and the body portion of the container.
- thermoplastic resin or adhesive 32 such as polyvinyl chloride and thermoplastic resin such as polyethylene or polypropylene or alternatively thermosetting epoxy resin, or vinyl plastisol is applied to an outer side 34 of the ring 12 and to an inner surface 36 of the lip prior to assembly of the dome to the lower portion so that after assembly the assembled can may be heated to a temperature melting the plastic adhesive during which time the top and bottom portions of the can may be relatively axially or circumferentially moved to eliminate any pinholes or the like formed in the adhesive and to promote good adhesion of the adhesive to the metal parts. Upon cooling, the adhesive 32 bonds the telescoped parts together.
- a metal closure 40 is shown in Figures 1-10 for purposes of illustration, it being understood that plastic closures of various kinds such as shown in Figures 11-13 may also be used.
- the closure comprises a center plug 42 which fits into the pour opening 44.
- the plug has an axially extending side wall 45 which at its lower end is connected to a bottom wall 46 and at its upper end has a downwardly open outward curl 48 which overlies the convex upper side 49 of the curl 25 and is drawn tightly against a foam gasket sealing material 50 applied thereto by mechanically crimping and expanding the side wall 45 of the plug to form a shoulder 51 under the curl.
- the wall 46, side wall 45 and curl 48 are scored at 52, 52 and a ring type opener 55 is formed with the closure or cap and bent downwardly to extend generally parallel with the conical section of the upper portion.
- the closure is readily opened by lifting the ring 55 thus breaking the scores 52, 52 and thus lifting the closure out of the pour opening.
- the side wall of the body portion of the can may be made of aluminum having a substantially uniform thickness on the order of 0.102 mm (4 mils).
- the side wall thickness has been maintained substantially uniform from end to end, there being no necessity for a thick zone about the open end since the double seaming has been eliminated. It is, however, feasible to make the entire side wall of the container, except for the extreme top, of a metal thickness of about 0.102 mm (4 mils) and the bottom of about 0.102-0.203 mm (4-8 mils).
- variable thicknesses may be incorporated in various zones of the side wall.
- the telescoping arrangement of the lip of the top and the necked-in band of the bottom portion and the provision of the outturned flange on the lower edge of the lip has been found to provide exceptional resistance to impact breeching of the connection.
- the flange 26 materially improved the radial strength of the lip portion of the top and the configuration of the lip and toroidal and conical sections develop a compression loading on the connection which together with the radial shoulder and necked-in band of the lower section resist inward displacement and thus do not extend peel stresses to the adhesive.
- the top portion of the container is an unstepped conical section.
- the transition from the toroidal section 15 to the curl is a smooth single conical section 60, a design which is satisfactory depending on the stacking strength required of the container.
- the necked-in structure at the upper end of the body section is eliminated and the upper end of the body portion 6 is a continuous cylinder which is slightly precompressed and fitted into the lip 14 of the top portion 3. The adhesive is thus held in compression between the lip 14 and the upper portion of the body 6.
- the bottom and top portions of the container are generally of the same diametrical dimension.
- the bottom portion is precompressed about its upper edge portion 8 prior to insertion into the top lip 14 of the upper portion and then is released compressing the adhesive 32 between the inner surface of the lip and the outer surface of the upper portion 14.
- the adhesive is preferably a thermoplastic type such that after the container portion of any of the previous or subsequent embodiments are assembled and they are passed through a heating chamber, the adhesive melts and fuses the top and bottom portions into a unitary structure.
- the joint is flexible because of the wall thicknesses being of the order of 4-9 mils, preferably the former for the body portion 6, and the adhesive is flexible.
- the extremely thin section of material that is the metal and the plastic adhesive, allows the joint to flex inwardly thus attenuating the forces and inhibiting these forces from applying peeling loads on the adhesive and separating the inner portion from the lip.
- the top is made to accommodate a different type of closure 100.
- the neck 102 at the top of the stepped cone 104 is elongated and has an inturned frustoconical lip 105 which forms a smooth apical annulus 106 against which the bottom side 108 of a radial flange 110 of the plastic closure 100 seats.
- the flange 110 is connected to a hollow sleeve 114 which fits into the lip 105 and has external sealing shoulders or rings 115 and 116. Shoulder 115 wedges against the top internal angular surface 117 of the lip 105 and the shoulder 116, which is at the bottom of the sleeve 114, underlaps the lower edge 118 of the lip 105 and tightly engages therewith.
- an integral tearable thin membrane 122 which is also integral with the outer peripheral edge portion 124 of a depressed closure plug 125 which is integrated with a hinge ring 126 connected by hinge 127 to the flange 110 and at the diametrically opposite side to a pull tab 130 which is angled downwardly toward the cone top portion. Lifting of the tab rips the membrane 122 and opens the container.
- the bottom 4 of the container is convex and has feet 75.
- the bottom wall thickness is usually the initial thickness of the blank sheet preparatory to forming of the can, that is 0.254-0.152 mm (10-6 mils), preferably 0.203 mm (8 mils), thick.
- the body wall 6 is ironed to about 0.127 mm (5 mils) or less.
- the top portion 3 is also less than 0.254 mm (10 mils) thick, preferably 0.102-0.228 mm (4-9 mils), and the pour opening 44 is less than 30% of the bottom area.
- the angle of the conical portions is between 10-45 degrees, preferably 22-1/2, in the stepped designs, as well as in the unstepped design of Figure 6. However, to obtain greater axial strength, an angle of 45 degrees would be preferred, but that is dependent upon other desired parameters as will be described in more detail hereinafter.
- the stepped design greatly improves the axial strength of the top.
- the dome 3 has a wall thickness t1 on the order of 0.228 mm (9 mils).
- the can body 8 has a wall thickness t2 of 0.081 mm (4 mils), but increases at its extreme upper end to a wall thickness t3 of 0.075 mm (6 mils) for a distance generally on the order of 0.152 cm (0.06 inch).
- the extreme upper end of the body 8 is provided with a radially inwardly directed curl 29.
- the ring 12 is radially inwardly offset and has an axial height on the order of 0.304 cm (0.12 inch).
- the lip 14 has a like axial extent and the torroidal section 15 has a preferred radius R1 of 0.304 cm (0.12 inch). The extent of the torroidal section 15 is such that the conical section 16 is disposed at an angle to the horizontal on the order of 22-1/2 degrees.
- the necking-in of the upper portion of the can body 8 provides a radially inwardly offset on the order of 0.152 cm (0.06 inch) with the shoulder 10 being joined to the ring 12 by a radius R2 to the remainder of the body 8 by a radius R3 which is also on the order of 0.152 cm (0.06 inch). It is to be noted that the shoulder 10 slopes upwardly and radially inwardly between the body 8 and the ring 12.
- Figure 16 wherein there is illustrated the geometry of the can which corresponds to Figure 15 and was considered as the basic can construction under consideration.
- Figure 17 there is illustrated both the original shape in solid lines and the deformed shape in dash lines of the can in the area of the joint between the body and the dome when the can was subjected to 7.03 kg/cm 2 (100 psi) internal pressure.
- a can was constructed as shown in Figure 19 wherein the dome 3 included a cylindrical portion 27 having an axial length of 1.27 cm (0.5 inch).
- the dome 3 included a cylindrical portion 27 having an axial length of 1.27 cm (0.5 inch).
- the force and moments of this modified can construction are generally the same as those of the standard, as indicated in Table I.
- a can as illustrated in Figure 21 was considered.
- dome angles of 10°, 45° and 90° were analytically tested. As shown in Table I, a dome angle of 10° was shown to be less desirable than a dome angle of 22.5° under both internal pressurization and axial fitment loading.
- the can with a modified radius of the neck-in was analytically tested with a neck-in radius of 0.076 cm (0.030 inch), and as is clearly shown in Table I, the results were not as good as when the radius was 0.152 cm (0.060 inch).
- the adhesive is applied to the body ring 12 and there is an interference fit between the dome and the body, any extra adhesive on the body, and there will always be some, will flow into the lower part of the lap and thus fill the free space between the lower edge of the dome and the adjacent portion of the body.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Rigid Containers With Two Or More Constituent Elements (AREA)
- Packages (AREA)
Description
- This invention relates to lightweight metal containers such as may be used to contain a beverage.
- Containers of the general type under consideration are primarily made of aluminum and have a cylindrical body with an integral bottom. The top is usually closed by a generally flat end member of different alloy than the body which is usually H 19-3004. The present commercial aluminum containers including ends weigh approximately 0.018-0.020 kg (0.040-0.045 pounds) each. The single service beverage cans of the 1960's includes a three-piece steel body, steel bottom and an aluminum top. The most popular can of the 1970's was an all aluminum drawn and wall-ironed can with a double seamed top. The top was of a different alloy than the can body.
- Aluminum, because of its light weight and ductility and being able to be easily cast, is finding growing uses, most recently in the automotive industry. Material costs are rapidly escalating and the supply is dwindling. Various structures have been made to shape the bottom of the can to obtain more volume with less strength. Inverted or concave bottoms were provided on the 1970 vintage cans to resist the pressure of the contents, however, this design is wasteful of the material in that a taller than necessary can must be provided necessitating additional material to obtain the desired volume. Furthermore, the flat top end on such cans requires the use of a strong alloy aluminum material having a magnesium content. The compositions of the body and that of the end of each can, being different, complicates recycling of the cans.
- Steel cans on the other hand, because of the thickness of the metal used, require high tonnage presses and tools must be more frequently replaced. When thick metal is used, the costs and carrying weights become excessive. In order to obtain an easy opening feature, steel cans invariably use aluminum tops which complicates recycling. The aluminum and the steel must be separated which is a time consuming costly process. The attractiveness of steel for cans is the lower cost of the metal and its great availablity.
- U.S.-A-2,197,434 relates to a metal container comprising a body, a top including a lower cylindrical lip and a conical inner and upper portion, the upper portion of the body and the cylindrical lip of the top forming a lapped joint.
- The object of this invention is to provide a metal container which uses less material but retains the strength characteristics of the present containers.
- Accordingly, the present invention provides a metal container comprising a body, a top including a lower cylindrical lip and a conical inner and upper portion, the upper portion of said body and said cylindrical lip of said top forming a lapped joint, characterized in that the adhesive layer is provided between said body and said top at said lapped joint, said container top comprises a dome in which said lip merges at its upper edge into a toroidal curve which merges into said conical inner and upper portion and wherein under internal pressure said conical portion is deformed generally axially upward and said toroidal curve is deformed generally radially inwardly with said lip being tilted radially inwardly to compress at least an upper part of said adhesive layer.
- Using the present invention, the concave bottoms of the principal current designs 0.0355 cm (0.014 inch) thick are replaced on the can of this invention formed of aluminum by a convex bottom about 0.0203 cm (0.008 inch) thick which results in a container of increased volume using less aluminum. The double seam of the current containers which also consumes aluminum is eliminated by substituting an adhesive telescoped joint. The top or dome of the new container may be about 0.229 mm (about 9 mils) thick compared to the double seam flat top of 0.356 mm (about 14 mils) thickness of the current containers. The heavy flange thickness 0.178 mm (about 7 mils) of double seamed cans is not required and is reduced to 0.102 mm (4 mils). A total package weight of about 9.07 kg (20 pounds) per one thousand cans is obtained versus 17.23-18.14 kg (38-40 pounds) per one thousand cans of the present lightest weight aluminum cans.
- The two pieces of the new can are assembled at the can plant and later filled through the small drink hole using conventional bottle fillers.
- It is postulated that using the present invention, steel cans 0.051-0.0635 mm (2 to 2-1/2 mils) in wall thickness are feasible. The elimination of a special alloy for the can ends by making the can of one alloy produces a uni-alloy can, therefore making it more valueable as scrap for recycling.
- The improved can remains cleaner, has better pourability and can be reclosed and resealed. The new container provides a top which increases container volume and can be as easily used for 0.47 I (16 ounce) cans as well as for 0.35 I (12 ounce) cans or even 0.28 I (10 ounce) cans merely by lengthening or shortening the can body. A further feature of the new container is that it can be made on present existing equipment without excessive capital investment.
- Advantage is taken of the shape of the top and of the thinness of about 0.022 cm (0.009 inch) and short axial length of the top with respect to the body length of the container to which the top is applied by shaping the top in a manner such that on filling the container with pressurized beverage internal pressure forces are exerted on the cone section of the top to cause beamloading of the cone section to exert inward forces on the lip at the base of the cone portion to assist the adhesive by applying compressive forces thereagainst and to the portion of the opposing body portion at the telescoped junction of the body and top. Peeling forces on the adhesive in the bonded telescoped junction as would ordinarily occur under internal pressure loading are thus eliminated. Various configurations of the top portion are shown which obtain specific benefits as hereinafter defined.
- In conducting studies with respect to the cans, with particular reference to the adhesive, it has been unexpectedly found that the adhesive, when placed in compression, exhibits a marked increase in shear strength.
- In 0.35 I (12 ounce) cans, the body has a diameter of 6.60 cm (2.60 inches) and an axial length of 10.16 cm (4 inches) whereas in the 0.47 I (16 ounce) can the body length or height is 12.06 cm (4.75 inches).
- In order to obtain a beaming action wherein the forces of expansion acting on the conical portion of the top produce compressive forces on the adhesive, the toroidal section, which provides the transition between the sloping conical section and the axial lip section, is arcuate in cross section and has a radius of 0.158 to 0.635 cm (1/16 to 1/4 inch). It has been found that as the material used becomes thinner, the radius must be made larger. If the beaming forces were to be restricted or with a sharp angle at the juncture, the conical portion would buckle and wrinkle adjacent to the lip.
- The invention comprehends providing a transition between the cone and the lip such that internal pressure forces tending to expand the conical section as well as the toroidal portion are utilized to produce a compressive force radially inwardly on the adhesive which together with the tensile forces tending to expand the upper end of the body portion ensures parallelism between opposing body and lip portions and thus precludes developing voids such as would produce leaking joints.
- Furthermore, the invention comprehends making an adhesively bonded joint as an extremely narrow axial band on the order of 0.158 to 0.317 cm (1/16 to 1/8 inch) which is now feasible because of the compressive loading on the adhesive.
- In steel cans to be comparable to the aluminum cans, the wall thickness of both the top and bottom sections of the can would be on the order of 2 to 2-1/2 mils thick or 0.30 mm (.0118 inch) thick.
- Although the can is in no way restricted to formation from aluminum, as indicated by the possibility of utilizing even thinner gauge steel, for the present it would appear that the best commercial aspects are with respect to a can formed of aluminum, and for that reason there has been established a can deemed most suitable for commercialization and that can, as well as various modifications of the can, have been subjected both to analytical and experimental tests. These tests clearly indicate that a specific relationship of the dome to the body provides for maximum strength with a minimum usage of metal and at the same time assures the formation of a lap bond between the body and the dome which will not be subjected to rupture under all expected conditions. Specifically, the applicant has found that metal containers made in accordance with the present invention can sustain at least a 36 kg (80 pound) axial load and an internal pressure of 7.03 kg/cm2 (100 psi).
- The invention will now be described with reference to the accompanying drawings, in which:
- Figure 1 is a perspective view of one embodiment of the invention.
- Figure 2 is a top plan view thereof.
- Figure 3 is a side elevational view thereof shown partly in axial section.
- Figure 4 is an enlarged fragmentary sectional view taken substantially on line 4-4 of Figure 3.
- Figure 5 is a view similar to Figure 4 showing the container wall portion partly inducted.
- Figure 6 illustrates a further embodiment incorporating a modified upper portion of the container.
- Figure 7 is a perspective view illustrating a further embodiment of the invention.
- Figure 8 is a top plan view thereof.
- Figure 9 is a side elevational view thereof partly in axial section.
- Figure 10 is an enlarged cross section taken substantially on line 10-10 of Figure 8.
- Figures 11-14 illustrate a further embodiment of the invention;
- Figure 11 being a perspective view;
- Figure 12 being a top plan view;
- Figure 13 being a side elevational view partly in vertical section taken substantially on line 13-13 of Figure 12, and
- Figure 14 is an enlarged portion of a part of Figure 13.
- Figure 15 is an enlarged fragmentary axial sectional view taken through the lap joint area of a preferred embodiment of dome and body relationship,
- Figure 1 6 is a schematic view showing the overall configuration of the dome and upper part of the body of a preferred embodiment.
- Figure 17 is a plot comparing the deformation of the dome and body in the lap area under internal pressure with the undeformed can shape.
- Figure 18 is an enlarged fragmentary plot of the can of Figures 15 and 16 comparing the deformed shape with the undeformed shape when the can is under a 36 kg (80 pound) axial fitment load.
- Figure 19 is a schematic sectional view of a modified can geometry having a lowered lap joint.
- Figure 20 is a plot of the deformed shape of the can of Figure 19 under internal pressure as compared to the undeformed shape.
- Figure 21 is a schematic sectional view of another modified can shape wherein the body has a straight wall.
- Figure 22 is a schematic sectional view taken through the lap joint and shows the arrangement of adhesive segments utilized in obtaining the analysis data of Table II.
- Figure 23 is a schematic sectional view through the lap joint showing the use of a six segment adhesive arrangement utilized in obtaining a portion of the analysis data of Table III.
- Figure 24 is a schematic sectional view through the lap joint showing the use of a nine segment adhesive arrangement utilized in obtaining a portion of the analysis data of Table III.
- An embodiment of the invention is shown in Figures 1-5 of the drawings as comprising a container, generally designated 1, preferably entirely formed of one alloy of aluminum such as H19-3004.
- The container has a lower or
bottom portion 2 and a top portion ordome 3. Thelower portion 2 comprises abottom 4 and an integralcylindrical body 6 which at itsupper end 8 is necked-in to provide a radially inwardly extendingshoulder 10 about 0.0793 to 0.158 cm (1/32 to 1/16 inch) wide and about the inner edge of which there is an axially extending annulus orring 12 of approximately 0.317 cm (1/8 inch) in length. - The annulus or
ring 12 preferably has a tight or interference fit into the lower end of an annular band orlip 14 of thedome 3 which is of an axial length corresponding to that of thering 12 while thedome 3 is about 2.12 cm (.837 inch) in total axial height. The upper edge of thelip 14 merges into the lower edge of a toroidal orarcuate transition section 15 which at its upper edge merges into the lower edge of aconical section 16. Thesection 15 has a radius of between 0.158 to 0.635 cm (1/16 to 1/4 inch) preferably the thinner the metal, the greater the radius. Theconical section 16 shown in Figures 1 and 5 is preferably of a stepped design and comprises a frustoconicalannular band 18 which merges at its lower edge with the upper edge of thetoroidal section 15 and the upper edge of theband 18 merges with the lower edge of aconical segment 20 which at its upper edge, in turn, merges into the lower edge of asecond smallerfrustoconical band 22. Theband 22 has its upper edge merging into the lower edge of a secondfrustoconical segment 24 which, at its upper edge, merges into acurl 25 which is turned outwardly over thesecond segment 24. - The lower edge of the
lip 14 is provided with an outturned downwardly flaring frustoconical or curledflange 26 which has an outer edge substantially coaxial with an externalcircular surface 30 and the body portion of the container. - A preferably thermoplastic resin or adhesive 32 such as polyvinyl chloride and thermoplastic resin such as polyethylene or polypropylene or alternatively thermosetting epoxy resin, or vinyl plastisol is applied to an
outer side 34 of thering 12 and to aninner surface 36 of the lip prior to assembly of the dome to the lower portion so that after assembly the assembled can may be heated to a temperature melting the plastic adhesive during which time the top and bottom portions of the can may be relatively axially or circumferentially moved to eliminate any pinholes or the like formed in the adhesive and to promote good adhesion of the adhesive to the metal parts. Upon cooling, the adhesive 32 bonds the telescoped parts together. - A
metal closure 40 is shown in Figures 1-10 for purposes of illustration, it being understood that plastic closures of various kinds such as shown in Figures 11-13 may also be used. The closure comprises acenter plug 42 which fits into the pouropening 44. The plug has an axially extendingside wall 45 which at its lower end is connected to abottom wall 46 and at its upper end has a downwardly openoutward curl 48 which overlies the convexupper side 49 of thecurl 25 and is drawn tightly against a foamgasket sealing material 50 applied thereto by mechanically crimping and expanding theside wall 45 of the plug to form ashoulder 51 under the curl. Thewall 46,side wall 45 and curl 48 are scored at 52, 52 and aring type opener 55 is formed with the closure or cap and bent downwardly to extend generally parallel with the conical section of the upper portion. The closure is readily opened by lifting thering 55 thus breaking thescores - The side wall of the body portion of the can may be made of aluminum having a substantially uniform thickness on the order of 0.102 mm (4 mils). The side wall thickness has been maintained substantially uniform from end to end, there being no necessity for a thick zone about the open end since the double seaming has been eliminated. It is, however, feasible to make the entire side wall of the container, except for the extreme top, of a metal thickness of about 0.102 mm (4 mils) and the bottom of about 0.102-0.203 mm (4-8 mils). However, if desired, variable thicknesses may be incorporated in various zones of the side wall.
- The telescoping arrangement of the lip of the top and the necked-in band of the bottom portion and the provision of the outturned flange on the lower edge of the lip has been found to provide exceptional resistance to impact breeching of the connection. The
flange 26 materially improved the radial strength of the lip portion of the top and the configuration of the lip and toroidal and conical sections develop a compression loading on the connection which together with the radial shoulder and necked-in band of the lower section resist inward displacement and thus do not extend peel stresses to the adhesive. - This feature is illustrated in Figure 5 wherein the body portion is depressed immediately below the necked-in region. The
shoulder 10 stops the body from deflecting inwardly and thus prevents peeling of the adhesive. Furthermore, the thin metal top, upon being pressurized, when the can is filled with pressurized beverage, becomes a prehensible member and wants to expand its conical section into a sphere. This, in turn, loads thelip portion 14 in compression which resists the expansion of the necked-inportion - In the embodiment of Figure 6, as well as all others, parts which are identical with the other embodiments are identified by the same reference numerals.
- As seen in Figure 6, the top portion of the container is an unstepped conical section. In this embodiment the transition from the
toroidal section 15 to the curl is a smooth singleconical section 60, a design which is satisfactory depending on the stacking strength required of the container. - In the embodiment of Figures 7-10 the necked-in structure at the upper end of the body section is eliminated and the upper end of the
body portion 6 is a continuous cylinder which is slightly precompressed and fitted into thelip 14 of thetop portion 3. The adhesive is thus held in compression between thelip 14 and the upper portion of thebody 6. - In this embodiment the bottom and top portions of the container are generally of the same diametrical dimension. The bottom portion is precompressed about its
upper edge portion 8 prior to insertion into thetop lip 14 of the upper portion and then is released compressing the adhesive 32 between the inner surface of the lip and the outer surface of theupper portion 14. The adhesive is preferably a thermoplastic type such that after the container portion of any of the previous or subsequent embodiments are assembled and they are passed through a heating chamber, the adhesive melts and fuses the top and bottom portions into a unitary structure. In this embodiment it will be appreciated that the joint is flexible because of the wall thicknesses being of the order of 4-9 mils, preferably the former for thebody portion 6, and the adhesive is flexible. Thus, when the container is struck with a side blow in the body wall adjacent to the joint, the extremely thin section of material, that is the metal and the plastic adhesive, allows the joint to flex inwardly thus attenuating the forces and inhibiting these forces from applying peeling loads on the adhesive and separating the inner portion from the lip. - In the embodiment of Figures 11-14 the structure of the
bottom portion 2 is the same as in the embodiment of Figures 1-5. - The top, however, is made to accommodate a different type of
closure 100. - In this embodiment the
neck 102 at the top of the steppedcone 104 is elongated and has an inturnedfrustoconical lip 105 which forms a smoothapical annulus 106 against which thebottom side 108 of aradial flange 110 of theplastic closure 100 seats. - The
flange 110 is connected to ahollow sleeve 114 which fits into thelip 105 and has external sealing shoulders or rings 115 and 116.Shoulder 115 wedges against the top internal angular surface 117 of thelip 105 and theshoulder 116, which is at the bottom of thesleeve 114, underlaps thelower edge 118 of thelip 105 and tightly engages therewith. At the juncture of the upper end of thesleeve 114 and theflange 110 there is provided an integral tearablethin membrane 122 which is also integral with the outerperipheral edge portion 124 of adepressed closure plug 125 which is integrated with ahinge ring 126 connected byhinge 127 to theflange 110 and at the diametrically opposite side to apull tab 130 which is angled downwardly toward the cone top portion. Lifting of the tab rips themembrane 122 and opens the container. - It will be noted that in each embodiment described above the
bottom 4 of the container is convex and hasfeet 75. The bottom wall thickness is usually the initial thickness of the blank sheet preparatory to forming of the can, that is 0.254-0.152 mm (10-6 mils), preferably 0.203 mm (8 mils), thick. Thebody wall 6 is ironed to about 0.127 mm (5 mils) or less. Thetop portion 3 is also less than 0.254 mm (10 mils) thick, preferably 0.102-0.228 mm (4-9 mils), and the pouropening 44 is less than 30% of the bottom area. The angle of the conical portions is between 10-45 degrees, preferably 22-1/2, in the stepped designs, as well as in the unstepped design of Figure 6. However, to obtain greater axial strength, an angle of 45 degrees would be preferred, but that is dependent upon other desired parameters as will be described in more detail hereinafter. The stepped design greatly improves the axial strength of the top. - Steps have been taken to develop the can for commercialization utilizing aluminum as the metal. Cans such as that generally illustrated in Figures 1-5 have been developed, but with slight modifications in the wall thicknesses, radii, axial dimensions and the like. Reference is made to Figure 15 which illustrates on a larger scale the specifics of the dome and can body in the vicinity of the lap joint between the dome and the can body with respect to what has been considered to be the most efficient construction.
- The
dome 3 has a wall thickness t1 on the order of 0.228 mm (9 mils). Thecan body 8 has a wall thickness t2 of 0.081 mm (4 mils), but increases at its extreme upper end to a wall thickness t3 of 0.075 mm (6 mils) for a distance generally on the order of 0.152 cm (0.06 inch). It is also to be noted that the extreme upper end of thebody 8 is provided with a radially inwardly directedcurl 29. Thering 12 is radially inwardly offset and has an axial height on the order of 0.304 cm (0.12 inch). Thelip 14 has a like axial extent and thetorroidal section 15 has a preferred radius R1 of 0.304 cm (0.12 inch). The extent of thetorroidal section 15 is such that theconical section 16 is disposed at an angle to the horizontal on the order of 22-1/2 degrees. - The necking-in of the upper portion of the
can body 8 provides a radially inwardly offset on the order of 0.152 cm (0.06 inch) with theshoulder 10 being joined to thering 12 by a radius R2 to the remainder of thebody 8 by a radius R3 which is also on the order of 0.152 cm (0.06 inch). It is to be noted that theshoulder 10 slopes upwardly and radially inwardly between thebody 8 and thering 12. - Experimental investigations of the can construction of Figure 15 and modifications thereof were made by IIT Research Institute of 10 West 35th Street, Chicago, Illinois 60616, U.S.A.
- It was determined in advance that there are two conditions which could place loadings on the can which could be destructive. These are:
- 1. Internal pressurization loads which may be as high as 7.03 kg/cm2 (100 psi).
- 2. An axial loading applied to the dome during the application of the closure fitment and which may be as high as 36 kg (80 pounds).
- Reference is made to Figure 16 wherein there is illustrated the geometry of the can which corresponds to Figure 15 and was considered as the basic can construction under consideration. In Figure 17 there is illustrated both the original shape in solid lines and the deformed shape in dash lines of the can in the area of the joint between the body and the dome when the can was subjected to 7.03 kg/cm2 (100 psi) internal pressure.
- Forces and movements in the body and in the dome were determined with respect to the meridional and circumferential directions. With a permissible yield stress of 3220 kg/cm2 (45,800 psi), maximum permissible yield thrust in the body is calculated to be 32.68 kg/cm (183 Ibs/inch and in the dome to be 73.57 kg/cm (412 Ibs/inch), and the maximum permissible yield bending moment in the body to be 0.055 cm-kg/cm (0.122 "Ib/inch) and in the dome to be 0.28 cm-kg/cm (0.618 "Ib/inch).
- The experiments showed the meridional force at the various points A-H (Figure 17) to be well within the permissible range. The same was generally true of the meridional moments. Also the circumferential forces and moments at the points A-H were within the permissible limit.
- The can of Figures 15 and 16 was also theoretically subjected to an axial fitment load of 38 kg (80 pounds) with the dome and the body deflecting as shown by the dash lines in Figure 18. In this instance the meridional forces and the moments circumferential forces and circumferential moments were negligible.
- Having established the can of Figures 15 and 16 as the preferred embodiment and thus as a standard, like internal pressure and axial fitment loading tests were run on other configurations. The modified shape parameters and a comparison of the results are found in Table I with the standard being identified by dashes and the modified shape parameters being compared with the standard with numeric identification from 1-4, with the
numeral 1 showing the test results of the modified shape parameter being better than the standard; thenumeral 2 showing the results to be the same as the standard; thenumeral 3 indicating the test results of the modified shape to be worse than those of the standard; and thenumeral 4 indicating test results which could possibly be critical including possible rupture or destructive failure of the dome or body. - It was found that having the lap between the dome and the body located immediately adjacent the
toroidal radius 15 of the dome and having thebody 8 necked-in produced the most desirable results. However, it was deemed advisable to change the lap location to be 1.27 cm (1/2 inch) below the dome radius to show the beaming effect of the dome on the lap and to connect the dome to a straight body to show the advantageous effect of the neck-in of the body on the lap. - Accordingly, a can was constructed as shown in Figure 19 wherein the
dome 3 included acylindrical portion 27 having an axial length of 1.27 cm (0.5 inch). As will be apparent from the deflection tracing, when the can of Figure 19 is subjected to 7.03 kg/cm2 (100 psi) internal pressure, the previously discussed beaming action has a lesser effect on the compression of the adhesive as shown in Figure 20 and will be discussed hereinafter. On the other hand, the force and moments of this modified can construction are generally the same as those of the standard, as indicated in Table I. With respect to the absence of a body neck-in, a can as illustrated in Figure 21 was considered. As shown in Table I, the force and moments under internal pressurization and axial fitment loading were generally the same as those of the sample of Figures 15 and 16. On the other hand, normal stresses in the adhesive under pressurization were below the standard as will be discussed in detail hereinafter. - It has therefore been concluded that the best possible combination is one wherein the lap is immediately adjacent the dome radius or toroidal curve, and there is a necking-in of the body. Returning now to Figure 17, it will be seen that under internal pressurization the dome
conical section 16 is angled upwardly to a greater extent and theradius 15 is deformed and moved radially inwardly so as to urge the upper portion of thelip 14 radially inwardly. At the same time the offset of the necked-in portion of the body tries to straighten out to eliminate theshoulder 10 and the lower portion of thering 12 moves radially outwardly so as to compress the adhesive. The placing of the adhesive in compression has the obvious beneficial effect of preventing peel. It further has the unexpected advantageous effect that when the adhesive is placed under compression it has greater shear strength. - Having determined that the can configuration of Figures 15 and 16 was the most desirable, tests were made by modifying other shape parameters. For example as indicated in Table I, dome angles of 10°, 45° and 90° were analytically tested. As shown in Table I, a dome angle of 10° was shown to be less desirable than a dome angle of 22.5° under both internal pressurization and axial fitment loading.
- When the dome angle was changed to 45°, the forces and moments remained substantially the same as those of the standard, but under internal pressurization the radial deflection of the adhesive layer worsened as will be specifically indicated hereinafter.
- In a like manner, when the dome angle was changed to 90°, which would result in a flat top and therefore not in accordance with the spirit of this invention, the forces and moments were generally the same as those of the standard, but both the radial deflection of the adhesive and the normal stress in the adhesive under internal pressurization worsened. This will be discussed hereinafter.
- Analytical experimentation was conducted relative to the dome torus radius, decreasing it in one experiment to 0.152 cm (0.06 inch) and increasing it to 0.609 cm (0.24 inch) in another experiment. As is clearly shown in Table I, a reduced dome radius produced undesirable forces and moments when subjected to internal pressurization. The stress in the adhesive was worse under axial loading.
- When the dome radius was increased, the forces and moments calculated to be either better or the same as the standard, but under internal pressurization the radial deflection of the adhesive layer and the normal stress in the adhesive layer worsened, as will be discussed hereinafter.
- When the thickness of the dome was reduced to 4 mils, the conditions worsened except for the radial deflection of the adhesive layer under internal pressurization. In fact, failure occurred when the dome was analytically subjected to the 36 kg (80 pound) fitment loading.
- The can with a modified radius of the neck-in was analytically tested with a neck-in radius of 0.076 cm (0.030 inch), and as is clearly shown in Table I, the results were not as good as when the radius was 0.152 cm (0.060 inch).
- The above described analytical tests were made by considering the total adhesive layer as being segmented into three, six or nine smaller circumferential rings as shown in Figures 22-24. This segmentation was necessary to implement the computer code and permit a prediction of the compressive forces distribution within the adhesive layer.
-
- Comparing the results of Table II with the merits of the different shapes of Table I, it will be seen that under all conditions the adhesive would be under compression when the can is subjected to 7.03 kg/cm2 (100 psi) internal pressure.
- Other specific tests relative to adhesive loading were made using a six segment adhesive arrangement as shown in Figure 23 when adhesive is applied only to the lap area, and a nine segment adhesive arrangement as shown in Figure 24 when the adhesive is permitted to fill the space between the dome and the body below the lap area.
- Referring to the foregoing Table III, it will be seen that when the adhesive fills the space between the dome and the body below the lap the compressive forces on the adhesive are greatly reduced under internal pressurization of the can and, in fact, in the lower part of the adhesive there are high tensile forces. While this would generally indicate that when the space between the dome and the body is filled with adhesive there is a poor joint, it is understood that even if that added adhesive should fail, the net result will be no less than that with the adhesive only in the lap in that the compressive forces on the remaining adhesive will increase to correspond to the case where there is adhesive only in the lap. On the other hand, the added adhesive will serve to prevent the entrance of foreign matter into the space between the lower edge of the dome and the body and thus does serve a useful purpose. Furthermore, because in the assembly of the dome and the body the adhesive is applied to the
body ring 12 and there is an interference fit between the dome and the body, any extra adhesive on the body, and there will always be some, will flow into the lower part of the lap and thus fill the free space between the lower edge of the dome and the adjacent portion of the body. - From the values of adhesive loading in Tables II and III, and it will be readily apparent that under the compressive loadings of adhesive in accordance with the can configuration of this invention, the adhesive has a much greater shear stress allowance than would normally be expected.
- It will become apparent from the foregoing disclosure that novel lightweight pressure holding containers have been developed which adequately contain pressurized beverages, use a minimum amount of metal and strategically employ the metal to obtain a container of improved characteristics which constrain the forces to act in a favorable manner assisting in holding the adhesive bond from being breeched.
Claims (20)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT81107280T ATE10728T1 (en) | 1980-09-26 | 1981-09-15 | LIGHT CONTAINER. |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US19122580A | 1980-09-26 | 1980-09-26 | |
US06/191,226 US4452368A (en) | 1980-09-26 | 1980-09-26 | Lightweight container |
US191225 | 1994-02-02 | ||
US191226 | 1994-02-03 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0048890A1 EP0048890A1 (en) | 1982-04-07 |
EP0048890B1 true EP0048890B1 (en) | 1984-12-12 |
Family
ID=26886872
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19810107280 Expired EP0048890B1 (en) | 1980-09-26 | 1981-09-15 | Lightweight container |
Country Status (9)
Country | Link |
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EP (1) | EP0048890B1 (en) |
AU (1) | AU542031B2 (en) |
BR (1) | BR8106173A (en) |
CA (1) | CA1163584A (en) |
DE (1) | DE3167726D1 (en) |
DK (1) | DK425981A (en) |
ES (1) | ES510422A0 (en) |
GB (1) | GB2084107B (en) |
GR (1) | GR75018B (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3275641D1 (en) * | 1982-11-19 | 1987-04-16 | Toyo Seikan Kaisha Ltd | Draw-ironed metal vessel having circumferential side seam |
DE3925068A1 (en) * | 1989-07-28 | 1991-02-07 | Schmalbach Lubeca | TWO OR THREE PIECE CONTAINERS, IN PART. MADE OF SHEET METAL |
DE3925069A1 (en) * | 1989-07-28 | 1991-02-07 | Schmalbach Lubeca | TWO OR THREE PIECE CONTAINERS, IN PART. MADE OF SHEET METAL |
DE102006021020A1 (en) * | 2006-05-05 | 2007-11-08 | Man Nutzfahrzeuge Ag | Container in a motor vehicle |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2384810A (en) * | 1940-05-13 | 1945-09-18 | Crown Cork & Seal Co | Container |
-
1981
- 1981-09-15 GR GR66077A patent/GR75018B/el unknown
- 1981-09-15 DE DE8181107280T patent/DE3167726D1/en not_active Expired
- 1981-09-15 EP EP19810107280 patent/EP0048890B1/en not_active Expired
- 1981-09-24 GB GB8128873A patent/GB2084107B/en not_active Expired
- 1981-09-25 DK DK425981A patent/DK425981A/en not_active Application Discontinuation
- 1981-09-25 CA CA000386698A patent/CA1163584A/en not_active Expired
- 1981-09-25 ES ES510422A patent/ES510422A0/en active Granted
- 1981-09-25 AU AU75686/81A patent/AU542031B2/en not_active Ceased
- 1981-09-25 BR BR8106173A patent/BR8106173A/en unknown
Also Published As
Publication number | Publication date |
---|---|
ES8303228A1 (en) | 1983-02-01 |
AU7568681A (en) | 1982-04-01 |
EP0048890A1 (en) | 1982-04-07 |
BR8106173A (en) | 1982-06-15 |
DK425981A (en) | 1982-03-27 |
AU542031B2 (en) | 1985-01-31 |
GB2084107B (en) | 1984-02-15 |
GB2084107A (en) | 1982-04-07 |
DE3167726D1 (en) | 1985-01-24 |
GR75018B (en) | 1984-07-12 |
ES510422A0 (en) | 1983-02-01 |
CA1163584A (en) | 1984-03-13 |
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Legal Events
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