CA1077385A

CA1077385A - Shrink wrappings

Info

Publication number: CA1077385A
Application number: CA303,070A
Authority: CA
Inventors: Mark A. Myers
Original assignee: Union Carbide Australia Ltd
Current assignee: Union Carbide Australia Ltd
Priority date: 1977-05-12
Filing date: 1978-05-10
Publication date: 1980-05-13
Also published as: GB1595530A; AU501507B1; IT7883379A0; IT1104954B; JPS53143486A; FR2390335A1; DE2820336A1

Abstract

SHRINK WRAPPINGS
ABSTRACT
A shrink wrapping for articles, e. g., bottles, is so constructed that it includes a carrier handle. The articles are placed between two webs of shrinkable plastics sheet material such that the articles are enwrapped by the webs at one end of the group of articles and across two opposite faces of the group. A lateral band is formed out of the webs at the other end of the group by laterally heat sealing the webs together so that the group then is fully surrounded in at least one direction by those portions of the webs not forming the band. The webs then are shrunk fit to the articles.

Description

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This invention relates to wrappin~s whereby a plurality of articles, such as bottles of drink or other containers or objects, may be grouped and firmly held together as a group for convenient carriage, storage or vending. More particularly, the invention is concerned with such wrappings which are applied loosely -to the group of articles and then shrunk to form a close envelope about the group. These wrappings are usually made of sheet or film material, being a well-known polymaric shrink film and preferably a low density polyethylene uni-oriented shrink film.
An object of an aspect of the present invention is to provide shrink wrappings for groups of articles which, in addition to providing the ordinary advantages attributable to shrink wrappings, also, in a vèry simple way, provides for the shrink wrapping to be equipped with a carrier handle effectively enabling the packaged group of articles to be carried as a single package in the manner of a handbag.
In accordance with one aspect of this invention there is provided a method of forming a shrink wrapping ahout a group of articles, comprising the steps:-` ta~ placing a group of articles between two webs of s~rinkable plastics sheet material so that the group is enwrapped by the webs at one end of the group and across two opposite faces of the group, (b) forming a lateral band out of the webs atthe other end of the group by laterally heat sealing the webs together along two spaced-apart parallel lines so that the group is then fully surrounded, in at least one direction, by those portions of the webs not forming the band, - ~ 2- .

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" ` 1077385 (c) simultaneously shrinking said portions and said band so that said portions become a close-fitting enwrapment of the group, and said band assumes rope form, and (d) after shrinking said portions and said band, piercing said portions at at least one point between said band and said group, thus to enable the shrunken rope-like band, in its entirety, to function as a handle for the carriage of the group.
In accordance with another aspect of this invention there is provided a method of forming a shrink wrapping about a group of articles, comprising the steps:-(a) placing a group of articles within a loopformed by webs of shrinkable plastics sheet material having the free ends of the webs joined together so that the group is enwrapped by the webs at one end of the group and across two opposite faces of the group, ~ b~ heat sealing together said webs at the other end of said group, along a first lateral line, thus fully to envelope the group longitudinally of said webs, (c) laterally heat sealing said webs together along a second lateral line spaced further from said group than said first line so as to form a lateral band longitudin-ally bounded by said lines, (d) separating said loop, including said band, from the non-wrapping remainder of said webs, `: (e) simultaneously shrinking the separatPd loop and said band, so that the loop becomes a close-fitting enwrapment of the group, and the band assumes rope-like form, and (f) piercing said webs on the group side of and adjacent said band but clear of the group, thus to enable the shrunken band, in its entirety, to function as a handle ~ for the carriage of the group.

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~0'773~5 Examples of the invention are illustrated in the draw-ings herewith.
Fig. 1 is a schematic side elevation of an assembly line in which the wrappings are applied to a group of bottles.
Fig. 2 is a perspective view showing a partly enwrap-5 ped group of three bottles which are also indicated at A in Fig.
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Figs. 3, 4 and 5 respectively illustrate stages in the final formation of the shrink wrapping and its handle.
Fig. 6 is a perspective view of a loop of shrinkable 10 plastics sheet material by which a modified embodiment of the invention may be practiced.
?Fig. 7 repeats the loop of Fig. 6 but with a group of articles enclosed in it.
Fig. 8 is an end view of the enclosed group shown in 15 Fig. 7 except for a band having been formed in the loop at one end of the group.
Fig. 9 repeats Fig. 8 except for the loop having been shrunk.
Fig. 10 is a plan projected from Fig. 9.
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~(~77385 ~ ig. 11 is a perspective view illustra~ing a further modification of ~he invention, Referring to Figs. l to 5, bottles 12 arrive by way of a kno~n kind of conveyor 13 (having back stop 14 and push feeder 15) in a thrusting station which places them, bottom end first, in groups of three, within a pair of webs forming a loop 16 fo:nmed, by join 17, from a pair of strips 18 and 1~ of shrinkable plastics sheet material.
: In this embodiment the width of strips 18 and 19 is substantially equal to that of the group (A) as indicated by dimension B in Fig~ 2, The strips 18 and 19 of sheet : material may be fed in known manner from magazine reels indicated at 20 and 21. The group of bottles A thus emplaced within loop 16 become longitudinally enveloped by the sheet material by laterally heat sealing (at 22) the loop webs together by way of vertically reciprocable bar heating elements indicated at 23, the group of bottles ; being only longitudinally enveloped in the sense that they are now longitudinally enco~passed by an open-ended tube or trunk 24 as shown in Figs. 1 and 2, ; The two webs are also laterally heat sealed `~ together along a second line 25 due to operation of the heater elements 23. This second heat sealing 25 is of the kind which severs the webs and thus forms, at the same time, an encasement for the articles such as that indicated at 24. The line 25 also constitutes the floor end of the next hottle-receiving loop to be made by forming the joint 17, ; - 4 -::`

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-. 10773~5 The breadth C o~ the band between lines 22 and 25 is so selected that the tensi]e strength of the band, in the direction of dimension B, is more than sufficient for the band, to become a container handle, reliably able to accept the loading due to the weight of the group of articles to be carried.
~ hen the wrapping of the bottles has proceeded to the stage indicated by Fig. 2, the partly wrapped groups proceed through a conventional shrink tunnel indicated at 26. Shrinkage of the applied wrapping causes the sheet material to bind the individual articles in the group tightly together and also causes the end portions 27 and 28 to be drawn together so that they then tightly curl about the ends of the group as indicated at 27A and 28A in Fig. 3. The shrunken wrappings may then be passed through a conventional cooling station as indicated at 29 and the packs thus formed are then pierced through the loop webs as indicated at 30 in Fig. 4 by reciprocable chisel-like punches or blades as indicated at 31, The band constituting the material lying between lines 22 and 25 may then be bowed outwardly from the remainder of the pack so to constitute a carrier handle as shown at 32 in Fig. 5.
It will be appreciated that piercing of the loop webs as referred to just above may be performed in many different ways. For example, by use of conventional air knives, or by use of thermal devices such as hot air, laser beam or heated hladesl . . . . .
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~77385 Referring to Figs. 6 to 10, the loop of shrinkable plastics sheet ma~erial is formed by an appropriate length 33 of an extruded tube of the material. The group of articles 34 is placed in the loop between two webs 35 of it.
The extrusion diameter of the tube is great enough, not merely for the tube to be able to encompass the group but also to provide a margin 36 out of which the band 37 may be constituted following lateral heat sealing as indicated at 38. The group is then fully encased, in one direction, by those portions of the webs not forming the band 37.
The encasement for the group is then shrunk as previously explained and as shown in Fig. 9, A single hole 39 may be pierced so to provide the handle 40 as shown in Fig. 10.
In some cases it is desirable for the shrink wrapping to provide a total enclosure for the group of articles. An example of this is provided in Fig. 11.
Referring to that figure, the loop of shrinkable plastics material is formed of two webs 41. These may be the opposite sides of a tube of the kind shown in Fig. 7 or they may be two separate free-edged rectangular layers heat sealed about the margins 42; so to provide a bag-like envelope in which the articles become wholly enclosed when the open end is heat sealed along a line such as that indicated at 43. This line is so placed as to define one longitudinal edge of a band 44 which eventually becomes a handle as previously explained; namely, after heat shrinking and piercing as ` - 6 -. ~
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described above. A second line of heat sealing may be provided at 45.
It will be understood that piercing of the webs in the vicinity of a band (such as that marked 37 in Fig. 9 for example) may be effected at different times depending upon what is suitable for the articles contained in the shrink package, For exa~ple~ in the arrangement shown in Figs. 1 to 5, piercing is performed as a step in the process of shrink package production because articles such as bottles have no need for total enclosure on the part of a wrapping therefor. On the other hand, with a package such as that of Fig 11 the articles contained in it may be of a perishable nature and hence it is desirable for the package to remain fully closed up to the point of retail sale. Under these circumstances the package is prepared up to the point of shrinkage of the webs about the group of articles, and the handle facility brought into being by the retailer, or the customer, piercing the loop webs adjacent the band, and clear of the group, with a pointed knife or the like, so to enable the band to become effective as a handle as previousl~ explained.

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Claims

CLAIMS:

1. A method of forming a shrink wrapping about a group of articles, comprising the steps:-(a) placing a group of articles between two webs of shrinkable plastics sheet material so that the group is enwrapped by the webs at one end of the group and across two opposite faces of the group, (b) forming a lateral band out of the webs at the other end of the group by laterally heat sealing the webs together along two spaced-apart parallel lines so that the group is then fully surrounded, in at least one direction, by those portions of the webs not forming the band, (c) simultaneously shrinking said portions and said band so that said portions become a close-fitting enwrapment of the group, and said band assumes rope form, and (d) after shrinking said portions and said band, piercing said portions at at least one point between said band and said group, thus to enable the shrunken rope-like band, in its entirety, to function as a handle for the carriage of the group.

2. A method according to claim 1 wherein said webs are formed from end portions of two strips, of said material, and whereof the free ends of said portions are heat sealed together prior to placement of the group between the webs.

3. A method according to claim 1 wherein said webs are formed by the walls of a length of tube extruded from said material.

4. A method according to claim 1 wherein said webs are formed by two free-edged rectangular layers of said material heat sealed together along at least one pair of lapping edge margins of the layers.

5. A method of forming a shrink wrapping about a group of articles, comprising the steps:-(a) placing a group of articles within a loop formed by webs of shrinkable plastics sheet material having the free ends of the webs joined together so that the group is enwrapped by the webs at one end of the group and across two opposite faces of the group, (b) heat sealing together said webs at the other end of said group, along a first lateral line, thus fully to envelope the group longitudinally of said webs, (c) laterally heat sealing said webs together along a second lateral line spaced further from said group than said first line so as to form a lateral band longitudin-ally bounded by said lines, (d) separating said loop, including said band, from the non-wrapping remainder of said webs, (e) simultaneously shrinking the separated loop and said band, so that the loop becomes a close-fitting enwrapment of the group, and the band assumes rope-like form, and (f) piercing said webs on the group side of and adjacent said band but clear of the group, thus to enable the shrunken band, in its entirety, to function as a handle for the carriage of the group.

6. A method according to claim 5 wherein the formation of said first and second lateral lines is performed simultaneously.

7. A method according to claim 5 wherein the formation of said first and second lateral lines and the separation of said loop from said strips are performed simultaneously.

8. A method according to claim 5 wherein the forma-tion of said first and second lateral lines, the separation of said loop from said strips and the joining together of those ends of the strips from which said loop has been separated are performed simultaneously.

9. A method according to any one of claims 1, 2 or 3 which includes the step of providing said webs in the form of a bag-like enclosure for said group so that upon formation of said band said enclosure becomes a total enclosure for said group.

10. A method according to claim 4 wherein said band is formed by heat sealing of said webs together along two parallel spaced-apart lines.

11. A method according to any one of claims 4, 5 or 6 which includes the step of providing said webs in the form of a bag-like enclosure for said group so that upon formation of said band said enclosure becomes a total enclosure for said group.

12. A method according to either one of claims 7 or 8 which includes the step of providing said webs in the form of a bag-like enclosure for said group so that upon formation of said band said enclosure becomes a total enclosure for said group.

13. A method according to any one of claims 1, 2 or 3 wherein said band is formed by heat sealing of said webs together along two parallel spaced-apart lines and which includes the step of providing said webs in the form of a bag-like enclosure for said group so that upon forma-tion of said band said enclosure becomes a total enclosure for said group.