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
  • B65D33/00—Details of, or accessories for, sacks or bags
  • B65D33/16—End- or aperture-closing arrangements or devices
  • B65D33/18—End- or aperture-closing arrangements or devices using adhesive applied to integral parts, e.g. to flaps

Definitions

• This invention relates to bags and is concerned with security bags which exhibit a visible indication if an attempt has been made to gain access to the contents of the bag.
• such bags are formed of sheet material including an opening giving access to the interior of the bag and the arrangement is such that the opening can be sealed by a closure member adhered to the opening-defining portions of the sheet material by means of a high tack adhesive.
• adhesives are hot melt or acrylic systems and although these are generally satisfactory, they have a limited working temperature because of their thermoplastic character.
• the bag it is possible, in some cases, for the bag to be opened and re-sealed without evidence of tampering by the use of elevated temperature.
• such adhesives tend to lose their tackiness at low temperatures.
• high ambient temperatures in some countries may exceed the useful working temperature of the adhesive.
• a bag formed of sheet material and having an opening to enable access to be gained to the interior of the bag, the bag including a closure member for superposition over the opening to close the opening and an adhesive formed of a cured silicone rubber-based composition for securing the closure member over the opening.
• silicone rubbers suitable for use in the adhesive compositions used in accordance with the invention areExamples of silicone rubbers suitable for use in the adhesive compositions used in accordance with the invention are dimethyl silicone rubbers. Typically, these include a plurality of structural units of the formula
• silicone rubbers are those known under the designation 280A, 282, and Q2-7406 of Dow Corning Corporation. These are silicone pressure sensitive adhesives which are ordinarily supplied in solution in xylene.
• the adhesive solution may be directly applied to the closure member or to the opening-defining portions of the bag so that the adhesive is located on the closure member or the opening-defining portions, respectively.
• the adhesive solution may be coated on to substrate to form a tape for securing to the closure member or to the opening-defining portions of the bag. After application of the adhesive solution, the coating is dried to remove the solvent and leave a tacky layer of the adhesive which will slowly cure in air.
• the rate of cure can be increased by incorporating a catalyst such as a peroxide or by subjecting the adhesive to elevated temperature.
• the degree of curing can be varied as desired but, even when fully cured, the adhesive retains its tackiness and, more importantly, it retains its tackiness at temperatures of from -65 C to +90 C.
• a primer may be desirable in the case where the adhesive solution is being applied to a polyethylene or polypropylene.
• FIG. 1 is a diagrammatic front view of an open security bag in accordance with a first embodiment of the present invention
• Fig. 2 is a diagrammatic section through the bag of Figure 1 on an increased scale
• Fig. 3 is a diagrammatic section showing the bag of Figure 2 when the bag is closed
• Fig. 4 is a diagrammatic section through an open security bag in accordance with a second embodiment of the present invention
• Fig. 5 is a diagrammatic section showing the bag of Figure 4 when it is closed.
• Fig. 6 is a diagrammatic section through an open security bag in accordance with a third embodiment of the present invention
• Fig. 7 is a diagrammatic section through the security bag of Figure 6 in its closed condition
• Fig. 8 is a diagrammatic section through an open security bag in accordance with a fourth embodiment of the present invention
• Figure 9 is a diagrammatic section through the bag of Figure 8 in its closed condition.
• the bag is formed from a single strip 1 of flexible thermoplastic sheet material such as polyethylene or polypropylene which is folded laterally along a fold line 2 to form a first portion 3 and a second portion 4.
• the thermoplastic sheet material is preferably transparent, partially transparent, or a combination of opaque and transparent so as to make it easier to see the evidence of tampering.
• the folded portions 3 and 4 are heat welded to each other in zone 5 which extends parallel with and close to each of the longitudinal and each of the lateral edges of the portions to produce an envelope-like bag 6 wherein the second portion 4 is longer than the first portion 3 and has a part in the form of an integral flap 7 forming a closure member.
• an opening line in the form of slit 8 extends across the first portion 3 terminating at each end at the weld zone 5. The slit 8 provides access to the interior of the bag 6.
• a 55% xylene solution of silicone rubber adhesive (Dow Corning Q2-7406) is applied across the full width of a part of the flap 7 and dried to remove the xylene to leave a band 9 of fully or partially cured high-tack silicone rubber pressure sensitive adhesive on the flap 7.
• a releasable cover strip 10 (for example formed of corrugated PVC tape) which is somewhat wider than the band 9 so as to provide finger-release edges.
• a band 11 of security printing which may for example be micro security printing, is applied across the outer face of portion 3.
• the band 11 extends across the full width of the portion 3 at such a position longitudinally thereof as to be immediately adjacent the adhesive band 9 when the flap 7 has been brought into its sealing position over the slit 8.
• the security printing is suitably applied in two inks, one comprising a hydrocarbon base and one comprising a hydrocarbon-free base.
• a further security feature is provided by virtue of the weld zone 5 being embossed over its full extent so that it is made impossible to gain access to the interior of the bag 6 across the zone 5 and then to re- seal the bag without the fact being made visually discernible by the consequent distortion of the form of the embossment.
• a line of perforations (not shown) is preferably provided across the flap 7 centrally of the adhesive band 9 so that any attempt to lift the flap 7 from the bag 6 is likely to be evidenced by tearing of the flap 7 at the line of perforations.
• a line of perforations 13 is provided across the flap 7 to provide a tear off receipt strip 12 which can be detached by tearing along the line of perforations 13.
• the disposition of the adhesive band 9 relative to the fold line for the flap 7 is such that when the flap 7 is brought down onto the portion 3, the part of the flap 7 carrying the adhesive band 9 straddles the slit 8 so that the slit 8 is completely overlain by said part of the flap 7 and the band 9 as shown in Figure 3.
• the slit 8 is completely sealed and there is no access opening whatsoever to the interior of the bag 6.
• the adhesive 9 is applied to both sides of the substrate 15 to form a double sided tape 17 having adhesive bands 9 at opposite sides.
• One of the adhesive bands is used to adhere the tape 17 to the flap 7 and then, after removal of the cover strip 10, the other adhesive band is applied over the slit 8 to seal the bag as shown in Figure 7.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Bag Frames (AREA)
• Package Frames And Binding Bands (AREA)
• Closures For Containers (AREA)
• Packages (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10674314

Family Applications (1)

Country Status (8)

Families Citing this family (20)

Family Cites Families (4)

• 1990
  • 1990-04-11 GB GB909008276A patent/GB9008276D0/en active Pending
  • 1990-10-30 SE SE9003462A patent/SE468924B/sv not_active IP Right Cessation
  • 1990-11-06 NL NL9002418A patent/NL9002418A/nl not_active Application Discontinuation
• 1991
  • 1991-04-09 IE IE117891A patent/IE911178A1/en unknown
  • 1991-04-10 PT PT9732291A patent/PT97322A/pt not_active Application Discontinuation
  • 1991-04-10 AU AU76659/91A patent/AU7665991A/en not_active Abandoned
  • 1991-04-10 WO PCT/GB1991/000563 patent/WO1991015406A1/en not_active Application Discontinuation
  • 1991-04-10 EP EP19910907598 patent/EP0531303A1/de not_active Ceased

Non-Patent Citations (1)

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