NZ280559A - Easy-open package; method and apparatus for forming package, tear strip applied by adhesive to envelope enclosing product, adhesive bond strength greater than envelope strength - Google Patents

Easy-open package; method and apparatus for forming package, tear strip applied by adhesive to envelope enclosing product, adhesive bond strength greater than envelope strength

Info

Publication number
NZ280559A
NZ280559A NZ280559A NZ28055995A NZ280559A NZ 280559 A NZ280559 A NZ 280559A NZ 280559 A NZ280559 A NZ 280559A NZ 28055995 A NZ28055995 A NZ 28055995A NZ 280559 A NZ280559 A NZ 280559A
Authority
NZ
New Zealand
Prior art keywords
adhesive
envelope
pack
tear strip
tear
Prior art date
Application number
NZ280559A
Inventor
Pietro Segota
Original Assignee
Grace W R & Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Grace W R & Co filed Critical Grace W R & Co
Publication of NZ280559A publication Critical patent/NZ280559A/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B65CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65BMACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B61/00Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages
    • B65B61/18Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages for making package-opening or unpacking elements
    • B65B61/182Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages for making package-opening or unpacking elements by applying tear-strips or tear-tapes

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Packages (AREA)
  • Labeling Devices (AREA)

Description

New Zealand No. 280559 International No. PCT/ TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates: 07.12.1994; Complete Specification Filed: 29.11.1995 Classification^) B65B61/18 Publication date: 25 March 1998 Journal No.: 1426 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: Method of providing an easy open pack, and pack made thereby Name, address and nationality of applicant(s) as in international application form: W.R. GRACE & CO.-CONN., a company organised under the State of Connecticut of 1114 Avenue of the Americas, New York, NY 10036-7794, United States of America 2805! Patents Form No. 5 P20732/ES NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION METHOD OF PROVIDING AN EASY OPEN PACK, AND PACK MADE THEREBY We, W. R, GRACE & CO.-CONN., a company organised under the State of Connecticut, United States of America, of 1114 Avenue of the Americas, New York, NY 10036-7794, United States of America, do hereby declare this invention to be described in the following statement: 28 0 55 9 la- METHOD OF PROVIDING AN EASY OPEN PACK. 5 AND PACK MADE THEREBY The present invention relates to a method of providing a film package with an easy open feature to facilitate tearing open of the pack by the consumer. The invention is particularly applicable to packages which involve the application of a shrinkable plastic film around a product, with shrinking of the applied film as one of the steps in the manufacture of the package.
In the past there have been various proposals for producing plastic film packs, for example by loading a product into a pre-formed bag or pouch of plastic film, and 15 then subsequently sealing the bag or pouch by welding or clipping, applying a plastic film round a succession of products in a form-fill-seal (either vertical or horizontal) process with subsequent heat sealing of the individual packs, inserting products into a centre-folded film between the superposed sides thereof and sealing, and over-wrapping a product with a shrinkable film and subsequently shrinking it. It is also known to 20 subject the closed pack to shrinking - for example in a hot air shrink tunnel -to tidy the packs.
It is also known to provide packs with an easy-open feature which presents a predetermined area of weakness (e.g. by scoring) or of unsealed contacting films, to 25 enable the consumer to initiate a tear or delamination of the pack by pulling the pack material, possibly -with the provision of an easy-open location by application of a stronger film portion as a tear tab or label, to initiate opening. Particularly in the case of the additional tear lab, the conventional method has the important disadvantage that the overall tidiness of the pack after shrinkage (which is after all one of the targets of 30 a shrink tidy operation) is marred by the uneven reaction of the packaging stronger tear tab Film to the shrinking heat. ^ ^ ■ i ; ■ - < C-6DEC 1995 28 0 559 Easy open features have, In the past, been used where there has been no shrink or only a small degree of shrink carried out to form the pack, because the difference in shrink properties of the basic packaging film and the teax strip applied thereto would lead to a loose package if more pronounced shrink is carried out. Furthermore, the tear 5 strip feature is only practical when the basic packaging film is of relatively low tear strength, otherwise the conventional tear strip system would be unable to initiate opening of the pack.
It is an object of the present invention to provide a method of creating an easy 10 open feature on a shrunk pack regardless of the strength of the pack, and regardless of the degree of shrink which is effected to form the pack.
In accordance with one aspect of the present invention there is provided a method of providing a pack, comprising taking an envelope of a heat-shrinkablc film enclosing a product, applying shrinking heat to cause the packaging film to apply itself more intimately to the product, and applying thereto a tear strip having a tear 2^ strength greater than that of the envelope, the application of the tear strip to the envelope being cffcctcd by way of an adhesive having bond strengths to the tear strip and the envelope which are greater than the tear strength of the envelope, and the adhesive being positioned close to and along a seal of the envelope.
A second aspect of the present invention provides apparatus for forming a pack comprising means for advancing a pack along a path, an adhesive application station along said path for applying a hot melt adhesive to the surface of the packs being passed thcrealong, and a tear strip application station for applying tea&^SpfgiBtcrial to r °% fe DEC X .c°/ '1 C 28 0 559 a quantity of hot melt adhesive on a pack passing the tear strip application station.
In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the 5 accompanying drawings in which:- Figure 1 - is a side elevational view of a machine for applying tear strips to completed packs; Figure 2a - is a view showing a pack prior to application of the tear strip thereto and prior to shrink tidying of the enveloping film material; Figure 2b - is a view of the pack of Figure 2a after shrinking; Figure 2c - is a view of the shrunk pack after the application of an adhesive thereto; Figure 2d - is a further view of the pack after application of a tear strip 20 to the adhesive; Figure 3 - is a top plan view of an alternative embodiment of the finished pack; pig. 4 - is a perspective view of a pack during opening by the consumer, and Fig. 5 - is a top plan view of a preferred embodiment of the finished pack.
Referring now to the drawings, Figure 1 shows the outlet of a shrink tunnel 1 feeding shrunk packs 3 onto a belt conveyor 5 past a first photosensing unit 7 towards an applicator 9 for a hot melt adhesive.
\ £■ M T ' ~ v* O ■, £ °!l \\ -6 DEC 1995 7 '• a n i 280559 After the application of the hot melt adhesive the packs 3 pass off the end of the belt conveyor 5 and onto a succeeding belt conveyor 11 which advances the packs from the adhesive application step to an application station 13 for a tear strip or label to be applied to the still soft adhesive.
Figure 2a shows one of the packs 3 as comprising a flat product 15, Ln this case a stack of slices of meat, within an envelope 17 comprising an upper layer 17a and a lower layer 17b of heat shrinkable Film material sealed around the perimeter of the product 15 along a continuous seal region 19. Thus far the pack of Figure 2a is in the condition in which it enters the shrink tunnel 1 whose exit is shown in Figure 1.
In Figure 2b the envelope 17 has been tightly shrunk into contact with the surface of the product (stack of slices) 15 and would be as illustrated exiting the shrink tunnel 1 in Figure 1.
In Figure 2c the pack is illustrated in the form in which it has just passed onto the second belt conveyor 11 from the first belt conveyor 5, after the application of a strip of hot melt adhesive 21 to its upper surface.
Finally, to arrive at the Figure 2d configuration, a tear strip 23 having a tensile strength greater than that of the film which forms the envelope 17 has been applied over the adhesive strip 21. The tear strip 23 may, if required, comprise a printed label of strong film.
When the hot melt adhesive of the strip 21 cools, it must have bond strengths to the tear strip 23 and to the envelope 17 which are at least as great as the tear strength of the film forming the envelope 17. Thus when the tear strip 23 is pulled by its non-adhered end 24 (Figure 2d), upwardly away from tiie upper surface of the envelope 17 lying on the product 15, the adhesive strip 21 will peel away from the remainder of the envelope 17 and will cause the envelope to open by local rupture. h r| -6 DEC 1995 H 28 0 559 The strip 21 of the hoi meli adhesive may be localised so that it defines a hole in the film layer 17a just large enough for the consumer to insert a finger or a suitable tool through the hole in the envelope 17 in order to initiate further rupture of the shrink envelope; alternatively the area of the adhesive strip 21 may be more extensive so as to allow a more substantial opening to be formed as the strip 23 is torn away from the envelope 1 7 Typically the hot-melt adhesive strip 21 is positioned along and close to a seal of the package. This is particularly suitable when the product is of soft consistency, as the option of providing a small hole to be prised open by the consumer with a linger or a tool can result in damage to the product. In such a case the application of the hoi melt adhesive along a seal to induce opening of the envelope along the seal ilself, would minimize the risk of damage to the product during withdrawal from the open pack In a preferred embodiment of the present invention, the envelope comprises a longitudinal seal and the hot melt adhesive strip 21 and the tear strip 23 arc positioned along said longitudinal seal.
Returning now to 1-igurel, there can be seen a supply roll 25 of continuous strip material which is threaded up over guide pulleys 27, 29 and 31, and hence onto applicator pulleys 33 which roll the strip material from ihc supply roll 25 flat onto the hot melt adhesive strip 21 (l-'igurcs 2c and 2d), leaving a non-adhered end 24 projecting beyond the end of the strip 21 of hot melt adhesive.
Typically ihc continuous strip on supply roll 25 is a carrier sheet with discrete labels 23 of strong film thereon to be applied one at a time to the packs. /"■ x. }■"%, o% 28 0559 The tear strip may in itself be laminated, but it is then important that the 5 strength of bonding of the layers to form that laminate should be at least as great as the bond strength between the laminate and the hot melt adhesive, in order to avoid delamination of the tear strip 23 upon tearing rather than removal of the tear strip 23 and adhesive 21 with the contacted region of the envelope 17 from the remainder of the envelope 17.
Although not essential to the understanding of the present invention, there are also shown in Figure 1 drive motors 37 and 39 under the main table 41 of the apparatus for driving the two belt conveyors 5 and 11; also supports for the various elements of the hot melt adhesive applicator 9 and the tear strip application station 13 are 15 illustrated.
The position of the first photocell 7 adjacent the first conveyor belt 5 is such that it detects the configuration of the series of packs 3 on the belt conveyor 5 when one of the packs is under the adhesive applicator 9 so that the applicator can then be 20 activated to dispense a strip of adhesive through its nozzle.
There is a second photocell 43 at the tear strip application station 13, to actuate indexing of the various guide rollers 27, 29 and 31, and the supply roll 25 of tear strip material, to apply the tear strip 23 to the already formed strip 21 of adhesive on the 25 pack detected by the photocell 43.
S °A 'V \\ V 2 - CM! °EC 1395 H j v V;.^ 28 0 55 9 The film material for the envelope 17 may be a heat shrinkable display film such as disclosed in GB-A-2115348 and GB-A-2135240. It may, equally, exhibit oxygen barrier properties such as is described in EP-A-0217596. has been heat sealed, and typical materials usea tor such bags are the films disclosed in (EP-A-0627465).
The hot melt applicator 9 may be a manually operated pneumatic model TR 60.3 available from Reka GmbH & Co. KG 15 of Germany or an electrically controlled pneumatic HM 250 applicator available from HOT MACHINES of Turin, Italy.
The tear strip application station 13 may use a commercially available label dispenser to apply the tear strip material to the adhesive 21 on the pack 3, and may for 20 example be a model Collamat 6010/20 available from Guhl & Scheibler AG of AESCH (Switzerland).
The hot melt adhesive used with the method of the present invention must provide high adhesion to both the outer layer of the envelope 17 and the underneath 25 surface of the tear strip material 23.
The tear strip material should also have a relatively low modulus of elasticity so as to be able to adhere to the surface of a shrunk pack even when that surface is somewhat uneven due to the shrinkage. It should have a high tensiie strength so that 30 it does not tear during the step of tearing open the pack, and equally it is preferable for there to be little or no elongation under tension, thereby avoiding stretching of-the film .-i' t- »* J As indicated at the outset above, the envelope 17 may of course be a bag which o 28 0 55 9 and ensuring that the effort applied by the consumer is utilised to rupture the envelope rather than to stretch the tear strip.
Typical adhesives which can be used are ethylene vinyl acetate - hot melt 5 adhesives, and one particularly preferred forms are those known under the designations SI84 and S/86, available from Elettrograf s.a.s. of Milan, Italy and VR 5001 available from Barbero Pietro of Grugliasco, Italy. Other food-approved adhesive materials with similar properties or a mixture of different such food-approved materials may be used, if necessary, in order to ensure good adhesion to the outer layer of the envelope 17 if 10 such high adhesion cannot be obtained with an EVA resin.
The pack made by the method of the present invention is particularly suitable for use with edible products, such as cheese, or stacked slices of meat.
The tear strip may be applied to the pack 3 by means of a single adhesive strip, or there may be two or more parallel strips of the hot melt adhesive, each holding the same tear strip 23.
A pack of the type having two parallel strips 21a and 21b is shown in plan 20 view in Figure 3, and an alternative type, with one strip 21 as described above,is shown in Figure 4 as the unadhered end 24 of the tear strip 23 is being pulled away to initiate tearing of the envelope.
Where several adhesive strips are used the rate of delivery of the hot melt from 25 the applicator 9 is kept constant so that a uniform quantity of resin is distributed along each adhesive strip such as 21 and 21b in Fig. 3. Where there is only one strip 21 of the adhesive, the rate of delivery of resin from the applicator 9 may be varied so as to apply a non-uniform quantity of resin along the strip as shown in Fig. 4. In this way the label will be adhered to the hot melt resin in such a way that there is a greater amount of hot melt adhesive at the end nearest to the grasping end 24 of the JabeL ; fc N v-i where the tear in the envelope 17 is to be initiated, than towards the oth^neffd where V ^ * _ . • \ -o DEC 1395 1 ' 'v. , o,/ - r (\> ^ 28 0 55 9 the tear would be well established, during opening by the consumer.
The hoi mek strip 21 can be applied along pari, or the whole, of the length of the longitudinal seal 34 of the pack 3, depending on the dimensions of the product and thus of the pack, and on the dimensions of the opening which is to be formed.
The quantity of hot melt adhesive applied to form the strip 21 may be as low as 0.3 grams per package, for a very small pack, but 5 or more grams may be use if the dimensions of the package and the size of the required opening dictate.
The photocells 7 and 43 can be used not only to initiate the application of tlie hot melt adhesive and of the tear strip, but also to control the positioning of the adhesive and tear strip. Suitable circuitry to allow a change in position for different pack types or sizes may be incorporated in the machine, or alternatively die positioning 15 of the photocell itself can be adjustable to change the location of the adhesive 21 and tear strip 23. to this longitudinal seal so as to locate it at an area of potential weakness of the 20 envelope 1 7 where opening is going to be most effective.
Equally, where the pack comprises some other inherent line of weakness, the hot melt adhesive strip 21 should be applied along the direction of the line of weakness, 25 and possibly partially overlapping it, in order to facilitate the initial opening.
Where the tear strip 23 is a label for the pack, it is important that that label should adhere firmly to at least pan of the hot melt strip 21, if not to the whole strip, and must have at least one free end 24 of a sufficient size to enable it to be gripped 30 between the consumer's fingers In order to apply the tearing force. Suitable materials Where, as in the case of a horizontal form-fiil seal pack or a vertical form-fill-seal pack, the pack has a continuous seam, the easy-open tear str«p is applied close 28 0 559 preferably with a sealant-coated side. Alternatively the tear strip 23 may be on plasticizcr paper or cardboard, where the coating material has a sufficient bond adhesion to the resin used for the body of the tear strip, and imparts the necessary strength to the substrate.
In a preferred embodiment the tear strip 23 is positioned on the package so that the free end 24 protrudes from the edge of the package surface- to ease gripping as indicated in Figure 5. Also preferably the tear strip 23 will bear an indication of the direction in which it should be torn in order to open the package As shown in Figure 5, this indication can be in the form of a partially opened zip Where the labels or other tear strips are supplied on a continuous carrier tape as disclosed above, the individual labels may be stuck on a strip of silicone release paper allowing them to be dispensed one at a time for application to the package.
Preferably the labels arc stuck on the silicone release paper by means of two lateral strips of pressure sensitive adhesive leaving a central adhesive-free strip for contact with the hot melt adhesive strip 21.
The method in accordance with the invention may, if desired, provide for the application of the hot melt adhesive first onto a part of the label so that adhesive/label combination can then be applied to the shrunk pack 3 in a single operation.
If desired the shrunk pack to which the method of the present invention is applied may be one which has a vacuum applied to its interior, or may be one having a modified atmosphere (for example of an inert gas or of carbon dioxide), within the envelope 17. 28 0 5 5 9

Claims (11)

WHAT WE CLAIM IS:
1. A method of providing a pack, comprising packaging a product in an envelope of a heat-shrinkable film, applying shrinking heat to the envelope and applying thereto a tear strip having a tear strength greater than that of the envelope, the application of the tear strip to the envelope being effected by way of an adhesive having bond strengths to both the tear strip and the envelope which are greater than the tear strength of the envelope, and the adhesive being positioned close to and along a seal of the envelope.
2. A method according to claim 1, wherein the adhesive is applied to the 10 pack and then the tear strip is applied to said adhesive to secure the tear strip to the pack.
3. A method according to either of the preceding claims, wherein die adhesive is a hot melt adhesive dispensed hot onto the Him to be sealed. 15
4. A method according to either of claims I and 2, wherein the adhesive is a hot melt adhesive applied to the envelope and subsequently heated to melting point to activate it. 20
5. A method according to cither of claims 1 and 2 wherein the adhesive is applied to the tear strip and die tear strip/adhesive combination is then applied to the envelope of the package.
6. A method according to any one of the preceding claims wherein said envelope has a longitudinal seal and the adhesive is applied along said longitudinal seal. »
7. A method according to any one of the preceding claims, wherein the tear strip is a printed label.
8. A method of forming a pack, substantially as hereinbefore described as reference to the accompanying drawings.
9. Apparatus for forming a pack comprising means for advancing a pack along a path, an adhesive application station along said path for applying a hot melt adhesive to the surface of the packs being passed therealong, a shrink tunnel upstream of said adhesive application station for shrinking the envelope of a pack before presentation at said adhesive application station, and a tear strip application station for applying tear strip material to a quantity of hot melt adhesive on a pack passing the tear strip application station."
10. Apparatus for forming packs, substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawings.
11. A pack formed by the method of any one of claims 1 to 8, or by the apparatus of claim 9 or claim 10. END OF CLAIMS McCABE AND COMPANY ATTORNEYS FOR THE APPLICANT Intellectual Property Onice of NZ 2 3 JAN 1958 RECEIVED
NZ280559A 1994-12-07 1995-11-29 Easy-open package; method and apparatus for forming package, tear strip applied by adhesive to envelope enclosing product, adhesive bond strength greater than envelope strength NZ280559A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9424719A GB9424719D0 (en) 1994-12-07 1994-12-07 Method of providing an easy open pack, and pack made thereby

Publications (1)

Publication Number Publication Date
NZ280559A true NZ280559A (en) 1998-03-25

Family

ID=10765567

Family Applications (1)

Application Number Title Priority Date Filing Date
NZ280559A NZ280559A (en) 1994-12-07 1995-11-29 Easy-open package; method and apparatus for forming package, tear strip applied by adhesive to envelope enclosing product, adhesive bond strength greater than envelope strength

Country Status (6)

Country Link
ES (1) ES2128218B1 (en)
FR (1) FR2727935B1 (en)
GB (1) GB9424719D0 (en)
IT (1) IT1277018B1 (en)
NL (1) NL1001760C2 (en)
NZ (1) NZ280559A (en)

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3391851A (en) * 1964-03-13 1968-07-09 Ibm Film removal tab
US3311032A (en) * 1964-12-24 1967-03-28 Procter & Gamble Tear tape for plastic packaging materials
US4083737A (en) * 1976-04-19 1978-04-11 Eastman Kodak Company Method and apparatus for attaching a strip of material transversely of a moving web
DE3716845A1 (en) * 1987-05-16 1988-11-24 Colgate Palmolive Co Process for the packaging of articles and packaging unit
US5067612A (en) * 1989-01-26 1991-11-26 Honshu Sangyou Kabushiki Kaisha Shrink film package having perforated folded strip
DE3915192A1 (en) * 1989-05-10 1990-11-15 Focke & Co METHOD AND DEVICE FOR PRODUCING (FILM) PACKAGING AND (FILM) PACKAGING
NL9002760A (en) * 1990-12-14 1992-07-01 Krehalon Bv SAUSAGE-SHAPED FOOD PRODUCT.
FR2699149B1 (en) * 1992-12-11 1995-11-17 Fabrice Lafleur EASY OPENING HEAT SHRINK FILM PACKAGING DEVICE, METHOD FOR MANUFACTURING SUCH A DEVICE AND MACHINE FOR CARRYING OUT SUCH A METHOD.
GB9306880D0 (en) * 1993-04-01 1993-05-26 Paper Sacks Ltd Multi-wall paper sacks
JPH08156963A (en) * 1994-12-07 1996-06-18 Fuji Seal Co Ltd Heat-shrinkable tubular body

Also Published As

Publication number Publication date
FR2727935B1 (en) 2000-02-11
NL1001760C2 (en) 1996-06-07
IT1277018B1 (en) 1997-11-04
ES2128218B1 (en) 1999-12-16
ES2128218A1 (en) 1999-05-01
FR2727935A1 (en) 1996-06-14
ITMI952530A0 (en) 1995-12-01
GB9424719D0 (en) 1995-02-01
ITMI952530A1 (en) 1997-06-01

Similar Documents

Publication Publication Date Title
AU730200C (en) Hermetically sealed package, and method and machine for manufacturing it
CA1225070A (en) Method of packaging, packaging material therefor and package
US4663915A (en) Method of packaging and apparatus
US5036643A (en) Form, fill, seal and separate packaging machine for reclosable containers including means for applying zipper to web
US3873018A (en) Easily rupturable band of tape
US7305805B2 (en) Method for making a flexible reclosable package
EP1375380B1 (en) Form-fill sealing machines, resealable flexible packages and methods of manufacturing resealable flexible packages
JPH10338244A (en) Sealed bag with tape stuck thereto and its production
US5157811A (en) Reclosable strip fastener with self opener
US8820381B2 (en) Apparatus and method for tin-tie application
AU2013241688A1 (en) Resealable package, method for producing the resealable package and apparatus for producing the resealable package
US4078659A (en) Heat shrunk carrier for bottles
GB2295807A (en) Applying tear strip to pack
US4722166A (en) Packaging
NZ280559A (en) Easy-open package; method and apparatus for forming package, tear strip applied by adhesive to envelope enclosing product, adhesive bond strength greater than envelope strength
GB2073130A (en) Re-closeable Package
JP2744186B2 (en) Packaging method for cup-shaped container and packaging device therefor
JP3628499B2 (en) Film welding / cutting equipment for easy-open heat-shrink packaging
JP2763630B2 (en) Method and apparatus for mounting adhesive tape having folded ends
JPH08324632A (en) Package body
JPH0710112A (en) Automatic packaging machine
CA1116135A (en) Sealed taped bags and sealed taped bag dispenser
JPH0369421A (en) Device for automatically sealing packed article
JPH0699944A (en) Side seal device of film
JPH0356206A (en) Method and device for automatic packaging

Legal Events

Date Code Title Description
RENW Renewal (renewal fees accepted)