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
  • B65D3/00—Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines
  • B65D3/10—Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines characterised by form of integral or permanently secured end closure
  • B65D3/12—Flanged discs permanently secured, e.g. by adhesives or by heat-sealing

Definitions

• the present invention relates to the production of flexible-walled containers intended to contain pressurized products such as beer or carbonate liquids. More particularly, it relates to the production of flexible material bottoms for these containers.
• Containers with flexible walls can be made from light and inexpensive materials, such as paper, plastic, metallic foil, or thin laminate complexes combining the qualities of various materials. These containers are economical. They also have the advantage of being much less dangerous than rigid containers if they are used as projectiles when they are full. Therefore, we recommend their use, during public events, for the distribution of drinks or various objects.
• the flexible walls are generally made of laminated materials with a core or at least an internal reinforcement which ensures mechanical resistance while appropriate coatings provide on each face the functions of resistance to corrosion or abrasion.
• the core of these flexible walls is often a thin sheet of aluminum which performs the functions of sealing and tensile strength but which has poor corrosion resistance. This core is protected on the internal side of the container by a coating which must be inert with respect to the content, and even aseptic if this content is a food or pharmaceutical product.
• the coatings of the internal faces of the body as well as of the bottoms must meet the same requirements. They are, most often, identical, or at least in very similar composition materials. They can therefore easily be glued or welded to each other.
• the edge of the internal plastic coating can be crushed to make it cover by creep the metal edge as proposed in French patents 1,440,935 and 1,571,778.
• the crushing of the plastic coating would not be regular enough. This technique is practically not applicable.
• the pressure forces which are exerted on the entire surface of the bottom, in particular on the annular groove, have, in fact, an axial resistance which pushes the bottom by tending to progressively unwind the annular groove towards the outside.
• the body connection area with the upturned edge of the cap forms an acute dihedral inside which exerts internal pressure which tends to open the dihedral and to progressively spread the flexible walls opposite.
• FR 2 311 730 gives a solution which consists in stiffening by an annular element added the connection groove between the domed cap of the bottom and its turned edge.
• this solution is expensive. It involves consumption of additional material corresponding to the manufacture of the rigid annular element. It requires an additional operation of placing the rigid element, an operation which can hardly be done at the current production and filling rates of the packaging.
• the object of the present invention is to provide a better solution to the problem of producing containers with flexible walls resistant to pressure, in particular to the production of the bottom edges and of their connection with the body.
• This solution consists, as in the last solution, in making a bottom in the shape of a domed cap bordered by a coaxial cylindrical collar. But, instead of the collar being composed only of an edge turned outward towards the top of the cap, it develops on either side of the plane defined by the periphery of the domed cap.
• the axial section of the bottom and its flange thus has a shape substantially in H and no longer in M.
• the section of the cap corresponds to the horizontal bar of H while the section of the cylindrical flange forms the two vertical bars, and on the other side of the cap.
• the collar thus comprises two substantially symmetrical elements:
• This second element corresponds to the edge returned from the flexible bottoms of the prior art with an M section, it surrounds and shelters the domed portion of the cap.
• This flange in two elements is connected tangentially with the periphery of the cap without inflection point. It considerably regidifies the bottom and makes any reinforcement element such as that proposed by FR 2 311 730 useless.
• the bottom in laminated sheet is produced from a blank in the shape of a glove finger composed of a cap and a cylindrical skirt extending the periphery of the cap. This cap is turned over by pushing it inside the skirt. We also return a skirt portion adjacent to the cap which comes inside the lower part of this skirt. The base of the skirt is possibly flared to form a side flange.
• the various operations for forming the bottom from a laminated sheet blank can be carried out practically simultaneously on double-acting presses operating at rapid rate.
• the coating protecting the internal face of the cap thus continues without any solution of continuity on the external face of the collar, this thanks to the rolling up of the skirt.
• the internal coating of the cap is identical or at least very similar to that of the body, the same is true for the external coating of the collar which is similar to the internal coating of the body.
• the connection between the flange and the body by welding or gluing over the entire height of the flange poses no problem.
• the diameters of the cap and its flange are chosen so that the flange fits right into the body of the container undergoing a very slight contraction which applies the opposite surfaces against each other.
• the H-shaped bottom formed by the cap and its protective flange forms a cartridge that is easy to install in the cylindrical body.
• the opposite faces of the skirt are linked to one another by means such as welding or gluing.
• This operation freezes the relative dimensions of the bottom, that is to say the height of the collar relative to the cap. This operation is generally done at the same time as the connection between the flange and the body of the container.
• Figure 1 shows in axial section a blank in the form of a thimble with a cylindrical skirt.
• Figure 2 shows in axial section the bottom after deformation of the flange, by inversion of the domed cap and part of the skirt of the glove finger.
• Figure 3 shows in axial section the bottom permanently fixed inside a container body by its flange.
• Figure 4 shows in axial section a similar bottom, also fixed inside a container body.
• the base of the collar is flared in the form of a flange.
• Figure 5 shows in axial section a container closed by two bottoms according to the invention.
• Figure 6 shows, in section perpendicular to the axis, the wall of the body at the longitudinal joint.
• Figures 7 and 8 show in plan and in section a bottom with an easy opening device by glued lid.
• the blank in the thermowell of FIG. 1 consists of a domed cap 1 and a cylindrical skirt 2 which extends around the periphery 3 of the domed cap.
• the domed cap has an arrow "f" and an outside diameter "d".
• the length "1" of the skirt 2 is greater than the arrow "f" of the cap 1.
• the thimble blank shown in FIG. 1 has a core 4 of aluminum sheet 0.14 mm thick. This sheet is protected against corrosion on each side by a layer of polyethylene.
• the polyethylene layer 5, which must be in contact with the product, inside the container, as shown in Figures 3 or 4, has a thickness of 80 microns.
• the layer 6 which must protect the aluminum against the atmosphere has a thickness of 30 microns.
• This blank J_ was itself obtained by stamping a flat blank, not shown.
• the internal layer 5 is present outside the blank as a thermowell, while the layer 6 is inside.
• h 6 mm
• e 3 mm
• f 11 mm
• d 55 mm.
• the bottom section has an H shape, the two vertical bars of which consist of the section of the collar 8 while the rounded bottom 1 'corresponds to the horizontal bar.
• the cylindrical collar 8 ⁇ consists of two elements: an upper lip 9 formed by a double wall thickness, of height h in the extension of the periphery 3 of the domed cap 1 'and a lower element 10 substantially similarly diameter d.
• This element 10 corresponds to the turned edge of US Patents 3,712,497 and FR 2,311,730, while the upper lip 9 provides by itself sufficient rigidity which makes an additional reinforcing element unnecessary as in the French patent.
• the upper lip 9 has been shown with a large thickness, whereas this thickness is in fact only of the order of 0.50 mm, the two wall thicknesses being applied one against each other.
• the domed cap 1 'of which is housed in a sort of cylindrical cartridge of diameter substantially d, of thickness ⁇ relatively thin, and of height h + f + e.
• This cartridge just enters the body 11 of the container with even a slight tightening of the order of 0.2 mm on the diameter.
• the lower element 10 of the collar 8 allows precise positioning of the curved portion with respect to the body 11, as shown in FIG. 3. It usefully reinforces the end of this body 11.
• the internal layer 5 of the domed portion of the bottom continues without a solution of continuity outside of the flange 8 and is located opposite the internal layer 12 of the body.
• the layers 5 and 12 of the bottom and of the body are here both made of polyethylene. They can be glued or welded without difficulty. The very slight tightening of the collar 8 in the body 11 is sufficient to ensure good contact of the facing surfaces over the entire height of the collar.
• the flange 8 is welded over its entire height to the internal layer 12 of the body, ie over the height h + f + e. Simultaneously, the layer 6 is welded onto itself over the height h corresponding to the lip 9 obtained by inversion of the skirt part adjacent to the domed cap 1a.
• the collar 8 is immobilized with respect to the cylindrical body 11 and the domed cap 1 'with respect to the collar 8. This double welding is easily carried out by heating the aluminum layers by high frequency induction.
• connection groove made of flexible material between the flange 8 and the domed cap 1 ′ does not have an appreciable surface oriented perpendicular to the pressure forces p in the axial direction and which is liable to gradually deform as is the case in US 3,712 497 and FR 2 311 730.
• the two walls of the thin lip 9 are substantially contiguous, closely linked by a weld zone 14.
• the external face of the lip 9 is itself linked to the body by the weld 15 over the entire height. h, here 6 mm.
• the axial force absorbed by the domed cap 1 ′ of diameter d_ is transmitted by the edge 3 in the form of a tangential tensile force over the whole of the lip 9. It does not apply, as in the art front, on the single connection line 16 between lip 9 and internal layer 12 of the wall 11, but is distributed over the entire height surface h of the welds 14 and 15. Finally, the lower element 10 of the flange is itself even welded to the wall 11. It helps to block the upper lip 9 by preventing any possibility of displacement by sliding of this lip against the wall 11. This lower element 10 reinforces the end of the cylindrical wall 11 which is the part of the container most exposed to shocks.
• the flange 8 of which is flared at its base in the form of a lateral flange 17, as shown in FIG. 4.
• the collar 8 To facilitate installation and welding of the bottom in the body, one can give the collar 8 a very slightly conical shape, tapering towards the center of the container.
• the internal surface of the cylindrical body 11 must not have any asperites of appreciable thickness.
• overlap welds of the types described in FR 1 359 243 or FR 1 571 771 are not used.
• the sheet is wound so that its two ends are presented end to end as shown in FIG. 6.
• the mechanical resistance along the longitudinal joint is ensured by welding or gluing of a resistant tape 18 to the outside of the container, while the sealing and the internal protection against corrosion are ensured by the application of a thin strip 19 of flexible material.
• This ribbon for example a "Saranex" ribbon from DOW CHEMICAL has a moisture-impermeable barrier layer 20 of polyvinilydene chloride protected on both sides by a thin layer of polyethylene
• the composite sheet constituting the body 11 represented in FIG. 6 is constituted like the bottoms of an internal protective layer 12 of polyethylene, of an aluminum sheet 21 and of an external layer 22 of polyethylene. However, to increase the rigidity of the container, this sheet 11 also comprises a layer of cardboard 23 with a thickness of the order of 0.4 mm.
• the external resistant tape 18 has a width 1 of 10 mm as well as the internal sealing tape 19.
• the tape 18 shown is cut from the same sheet as that constituting the body.
• the internal tape 19, very malleable and flexible, has a thickness of 0.08 to 0.1 mm. When each bottom is put in place, it is partially pushed back into the longitudinal gap 24 between the ends which come end to end of the sheet constituting the body 11. The edges of this strip 19 are simultaneously flattened in a bevel and are connected practically without roughness with the polyethylene layer 12.
• FIGS. 7 and 8 For chemically less aggressive products, such as carbonated water, an easy opening device can be produced as shown in FIGS. 7 and 8.
• One or more perforations 25 are before stamping in the flat blank in which the bottom must be formed. These perforations 25 are closed with a thin cover 26 which is fixed by gluing. The blank and the cover 26 are formed at the same time and the device shown in FIGS. 7 and 8 is obtained very economically.
• the surface layers for protection against corrosion and humidity, 5, 6, 12, 22 are made of polyethylene. These protective layers can be made of various other plastics or varnishes. Thus, the outer layers 6 and 22 are frequently made of varnish with a thickness of the order of 10 microns.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Closures For Containers (AREA)
• Rigid Containers With Two Or More Constituent Elements (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Laminated Bodies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9226066

Family Applications (1)

Country Status (13)

Cited By (5)

Citations (3)

• 1979
  • 1979-05-23 FR FR7913924A patent/FR2457223A1/fr active Granted
• 1980
  • 1980-05-16 IT IT22122/80A patent/IT1193934B/it active
  • 1980-05-18 AR AR281095A patent/AR223525A1/es active
  • 1980-05-19 WO PCT/FR1980/000079 patent/WO1980002544A1/fr active IP Right Grant
  • 1980-05-19 DE DE8080900924T patent/DE3063073D1/de not_active Expired
  • 1980-05-19 JP JP50108880A patent/JPS56500567A/ja active Pending
  • 1980-05-19 BR BR8008691A patent/BR8008691A/pt unknown
  • 1980-05-19 AT AT80900924T patent/ATE3268T1/de not_active IP Right Cessation
  • 1980-05-20 GR GR61998A patent/GR67668B/el unknown
  • 1980-05-22 ZA ZA00803071A patent/ZA803071B/xx unknown
  • 1980-05-22 BE BE0/200719A patent/BE883431A/fr not_active IP Right Cessation
  • 1980-05-22 ES ES1980250878U patent/ES250878Y/es not_active Expired
  • 1980-12-01 EP EP80900924A patent/EP0029039B1/fr not_active Expired

Patent Citations (3)

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