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
  • B65D75/00—Packages comprising articles or materials partially or wholly enclosed in strips, sheets, blanks, tubes, or webs of flexible sheet material, e.g. in folded wrappers
  • B65D75/52—Details
  • B65D75/58—Opening or contents-removing devices added or incorporated during package manufacture
  • B65D75/5805—Opening or contents-removing devices added or incorporated during package manufacture for tearing a side strip parallel and next to the edge, e.g. by means of a line of weakness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2155/00—Flexible containers made from webs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B2170/00—Construction of flexible containers
  • B31B2170/20—Construction of flexible containers having multi-layered walls, e.g. laminated or lined
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31B70/00—Making flexible containers, e.g. envelopes or bags
  • B31B70/74—Auxiliary operations
  • B31B70/81—Forming or attaching accessories, e.g. opening devices, closures or tear strings

Definitions

• This invention relates to flexible packaging units intended, to be opened by tearing and to means for controlling the opening by tearing.
• the invention provides a method of constructing a flexible packaging unit to facilitate controllable opening thereof by tearing. Further, the invention provides a flexible packaging unit incorporating tear control means for facilitating its controllable opening.
• European patent EP 0471220 discloses a pouch having a thin-walled part for easy tearing, the thin wall part incorporating strings in the plastic film that makes up the wall; the strings being pullable to open the pouch.
• a drawback of this invention too is the requirement of providing special elements, in this case the strings, adding complexity to the manufacture thereof.
• EP 0325993 describes a bag having a tear strip that is defined by parallel perforated lines. The perforations are backed by a sealing strip to maintain the hermetic integrity of the bag's interior. Again, this invention has the drawback of increasing complexity of manufacture.
• EP 0423456 discloses a bag having zipper means rendering it reclosable and a tear strip for facilitating the initial opening.
• the tear strip can be located internally and externally at the apex of the bag. Protection against unwanted propagation of the tear towards the zipper elements is achieved by providing the zipper elements each with an extended base portion to reinforce the film of the walls and to keep the tear from reaching down to them. This invention adds further to the material requirements for manufacture.
• An advantage of the present invention is to provide a container having a bounded tear area in which tearing is confined in a construction that avoids having a tear strip.
• An advantage of the present invention is to provide barrier means for preventing the tear from propagating to the top edge of the container.
• a flexible container comprising opposed front and back walls sealed together proximate to their edges to define an internal space, a pair of tear-limiting strips applied to a surface of each wall or located within each wall so that the strips on or within opposed walls coincide substantially, defining corresponding tear paths.
• the strips have substantially greater tear resistance than the walls.
• the strips of each pair are spaced from about 0.1mm to about 6mm apart, preferably about lmm-2mm and further preferably from about 1.2mm to 1.8mm.
• the strips of each, pair are located to be substantially parallel to each other.
• the strips comprise sealable strips.
• the strips are self-adhesive.
• the strips are about 1mm to about 5mm in breadth, preferably from about 1.5mm - 2.5mm,
• the strips may all be located on the outer surface of the walls.
• the strips are all located on the inner surface of the walls.
• one pair of strips is located on an inner wall surface and the other on an outer wall surface.
• one strip in each pair is located on an inner surface and the other strip is located on an outer surface of each wall.
• a strip may be located to be on a surface between laminate materials making up the wall material.
• the thickness of the strips is in the range from about 12 - 100 microns, preferably about 20-50 microns.
• the strips are made of polypropylene (PP).
• the strips may be made of polyethylene (PET). NO 7501
• a flexible-walled container having opposed back and front walls, each wall having a respective top edge, the walls being sealed together proximate to the respective top edges defining an internal space between them, and tear barrier means provided on or within each wall, defining a tear path located to be spaced from at least a part of the top edge thereof
• the tear paths are defined by paired spaced barrier strips resistant to tearing.
• a method of mmufacttrring a flexible walled container comprises the steps of providing first and second films, providing tear barrier material in strip form, applying the tear barrier material in paired strips to each film so as to define a substantially coinciding tear path on each and arranging the films in opposition to form a container comprising substantially coinciding tear paths on each wall.
• the invention further provides a method of manufacturing a sealable bag, the method comprising the steps of providing a flexible film and forming it into a container defining an internal space bounded by respective front and back walls, and applying a tear barrier strip to the walls to define a bounded tear path on each of the front and back walls.
• the tear barrier is of substantially greater tear resistance than the flexible film to which it is applied.
• Figure 1 presents in A a side view of an embodiment of a flexible container of the invention and in B a cross section of the container along line A- A'.
• Figure 2 is a side view of an alternative embodiment of the invention. NO 7501
• Figure 3 is a side view of a further alternative embodiment of the invention.
• Figure 4 is a schematic illustration of a process of manufacture of a container according to the invention.
• the invention provides for the definition of substantially coinciding tear paths on opposing walls of a flexible packaging unit made of a tearable film, for example a film of plastics material or a laminate.
• the tear path is designed to facilitate the opening of the container in a controllable manner by a consumer desirous of accessing the contents. By limiting the propagation of the opening tear to a defined path, a cleaner open may be obtained and the likelihood of spillage, waste and messing reduced.
• the packaging unit may be a pouch container or a bag or the like.
• the tear paths are defined by applying tear limiting elements in the form of barrier strips in pairs to the surfaces of the container walls or to sheets m laminated material making up the walls.
• the strips are substantially parallel to each other.
• the barrier strips may be applied to the inner or outer surfaces of the container and in any combination.
• the strips are all applied to the outer surfaces at corresponding positions. However, they may also be applied to the opposing inner surfaces.
• one pair may be applied to an inner surface and the other to the outer surface of the opposing wall.
• one strip in a pair may be applied to art outer surface while its partner may be applied to the inner surface of the same wall. Where the wall is constructed of a laminate material, one of more of the strips may be located between adjacent layers in the laminate.
• the strips are preferably spaced apart from about 0.1mm to about 6mm and further preferably from about 1mm to about 2mm. In a particularly preferred embodiment, the strips are spaced apart by about 1.3mm to about 1.8mm, NO 7501
• the strips are comprised of tear tape that is sealable or preferably self adhesive.
• Each strip desirably may have a width in the range from about 1mm to 5mm, preferably from about 1.5mm to about 2.5mm.
• Desirably the strips have a thickness in the range from about 12 microns to 100 microns, preferably from about 20 to about 50 microns. Factors such as strip thickness, strip width and grade of strip tape material will determine the strip tear resistance in comparison with the tear resistance of the film from which the container is fashioned.
• the strips are preferably made of polyester or polyethylene (PET), Where the containers are intended to house a dry product and not be subjected to a retort stage, they may conveniently be made from polyproylene (PP) tape. Polyester tape may however also be used, as may other suitable tape materials known in the art.
• PET polyethylene
• PP polyproylene
• the pouches may conveniently be of the doypack ype or be 3- or 4-sidedly sealed pouches. However, other pouch configurations may be employed.
• the pouch material may be PP, PET and larninates comprising two or more of PP, metallised foil, e.g. aluminium foil (Alu), poly-acrylamide (PA), PET, fibre sheeting, such as paper, and PE.
• metallised foil e.g. aluminium foil (Alu), poly-acrylamide (PA), PET, fibre sheeting, such as paper, and PE.
• PET/Alu/PP for retorted product applications
• PET PP or PP PE for dry product applications. Further layers may be added, depending on the product application and processing and the degree of tear resistance required in comparison with the tear-limiting strips to be applied.
• a notch may be formed at an edge of the container wall.
• a hole may be punched at a suitable location where the opposed walls are sealed together.
• the notch or hole is sealed around its edges to maintain the airtight integrity of the container.
• the tear limiting tape strip may be applied to each side of the notches or punched holes.
• the flexible container 10 illustrated in Figure 1 has opposing walls 12, 14 sealed together at region 16, proximate to top edges 18, 20.
• barrier strip 22, 24 applied externally to the wall 12, 14.
• barrier strip 26, 28 Spaced from barrier strip 22, 24 is a second barrier strip 26, 28.
• a tear area 30, 32 Between the upper and lower barrier strips is defined thus a tear area 30, 32.
• a notch 34 is provided to facilitate initiation of a tear in the tear area.
• FIG 2 illustrates in cross section an embodiment of laminated wall sections to which barrier strips are applied, according to the invention.
• tear barrier strips 22, 24, 26 and 28 are located internally in walls 12 and 14, being placed between adjacent layers of aluminium foil 38 and polypropylene 40.
• An external layer 42 of polyethylene PET is applied over the aluminium foil 38. The layers are sealed together at heat seal 44.
• Figure 3 illustrates a further exemplary embodiment, in which the barrier strips 22, 24, 26 and 28 are placed externally to the container, being applied as self adhesive tape to the outer polyethylene surfaces of layers 42.
• a wall material for a tearable flexible container of the invention may be manufactured by providing a flexible film for forming a wall of the container, such as a laminate of alufoil and polyethylene, providing a tear barrier element having substantially greater tear resistance than the wall film, for example a polypropylene tape, locating the element on the film to define a tear path thereon, and fixing the element to the film.
• the barrier element in strip form may be adhered to the film through use of an adhesive, or may be thermally bonded to it.
• Figure 4 illustrates a method of manufacturing a laminated flexible sheet material foil for use in forming the bag of figure 1.
• NO 7501 the NO 7501
• walls 12, 14 are constructed of a laminated sheet comprising a foil 42 on a polyethylene film 44.
• the tear barrier comprises polyethylene strips 22, 26 applied to the foil 42.
• the foil is preferably metallised and may for example be an aluminium foil ("alufoil").
• the barrier strips are of polyester and optionally covered by a layer 46 of polypropylene extruded over them, h figure 2, the polypropylene layer 46 is applied by means of an extrusion hopper 48. Irregularities 50 in layer 46 are smoothed out by passing the layer under a correcting roll 52.
• the adhesive on the strip is a self- adhesive material delivered in reel. No high temperature treatment is needed for the application which is done by simple contact by unwinding a tape while unwinding the film.
• the strip and its applicator are obtainable from the company PP Payne of Nottingham, England.
• An advantage of the invention is that it provides a highly reliable guided tear in both opposing walls of the container, along a bounded path leading from one edge to another, be it from a side edge to the opposite side edge or from the top edge to a side edge or from a side edge to a defined part of the top edge.
• a further advantage is that the package and the guide strips defining the tear path are all retortable.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Bag Frames (AREA)
• Packages (AREA)
• Laminated Bodies (AREA)
• Making Paper Articles (AREA)
• Cartons (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34042855

Family Applications (1)

Country Status (12)

Families Citing this family (19)

Citations (6)

Family Cites Families (11)

• 2003
  • 2003-08-18 EP EP03018560A patent/EP1508530A1/de not_active Ceased
• 2004
  • 2004-08-17 MX MXPA06001779A patent/MXPA06001779A/es unknown
  • 2004-08-17 AR ARP040102950A patent/AR046007A1/es unknown
  • 2004-08-17 JP JP2006523600A patent/JP2007502753A/ja active Pending
  • 2004-08-17 CA CA2534881A patent/CA2534881C/en not_active Expired - Fee Related
  • 2004-08-17 CN CNA2004800236659A patent/CN1835871A/zh active Pending
  • 2004-08-17 RU RU2006108545/11A patent/RU2330797C2/ru not_active IP Right Cessation
  • 2004-08-17 US US10/568,309 patent/US20070269146A1/en not_active Abandoned
  • 2004-08-17 AU AU2004264388A patent/AU2004264388B2/en not_active Ceased
  • 2004-08-17 BR BRPI0413605-5A patent/BRPI0413605A/pt not_active IP Right Cessation
  • 2004-08-17 WO PCT/EP2004/009251 patent/WO2005016781A1/en active Application Filing
• 2006
  • 2006-03-17 ZA ZA200602256A patent/ZA200602256B/en unknown
• 2010
  • 2010-10-08 JP JP2010228944A patent/JP2011042408A/ja active Pending

Patent Citations (6)

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