GB2038270A - Folded tubular preform for packaging containers - Google Patents

Abstract

A tubular preform 2 for shrinking around bottles is formed from a sheet 1 of flexible, opaque, heat-shrinkable, biaxially oriented thermoplastics material which is a composite foam and film laminate, the preform having a thermal fusion or adhesive seal 2c extending in an axial direction, and being flat-folded with a pair of axial pleated folds 2d in diametrically opposite sides, with an off-centre transverse fold 2g also being provided. The preform is printed, except in the area of the seal 2c. The folded preforms 2 are packaged in boxes or envelopes for transport. <IMAGE>

Description

SPECIFICATION Tubular preform for packaging containers I. Field of the invention This invention relates to the art of making tubular sleeves suitable for application to an assembled group of containers, such as glass bottles and the like. The tubular sleeve constitutes novel banding material and structure especially desirable for assemblying and heat-shrinking around the grouped containers so that the major exposed surfaces of such similar containers are held in tightlyconstrained tangential relation.

2. Description of the prior art It is common practice to merchandise many items such as containers for soft drinks, beer and the like, in packages containing a number of containers with the package normally including a handle or other hand holding means to facilitate carrying the package. A most common package consists of a relatively-rigid paperboard blank formed around a group of containers, normally six or eight, with the folded blank usually being interlocked with itself and the like containers in the package. The paperboard packages normally require partitions between individual containers, especially in the case of glass bottles, to avoid surface-to-surface contact.These paperboard blank packages have not been entirely satisfactory in that they are relatively expensive and are comparatively difficult to form, particularly with the high speeds required by modern filling, capping and packaging machines.

To overcome these and other deficiencies of the folded paperboard blank, cans have recently been packaged by assemblying the cans with a multiapertured carrier formed from a sheet of resilient plastic material with the beaded end of the cans each being inserted through the apertures. The periphery of the apertures grasp the sidewalls of the cans and are locked beneath the bead securely enough to permit carrying of the package by a handle or finger holes formed in a central portion of the resilient plastic carrier. Heretofore, it has not been considered practical to package bottles in this manner because the elongated neck and shoulder portion projecting upwardly from the cylindrical body portion have made existing methods and apparatus for the retention of cans in a multi-pack impractical or unduly expensive for packaging bottles.Further, the relatively great distance over which the carrier must be moved in its application onto the body portion of the bottles has made it necessary to install the carrier on successive bottles substantially simultaneously to avoid excessive distortion and tearing of the plastic carrier. Also, the side surfaces Qf bottles require additional retention means such as an encompassing band to avoid surface-to-surface impact of the bottles during handling, shipment and disassembly of the package. Such apparatus for packaging containers is disclosed in U. S. Patent No. 3,509,684 to Hohl and Scribner, which patent is assigned to the same common assignee as the present invention.

More recently, the introduction of shrinkable plastic overwraps has occurred causing drastic changes in the paperboard packages of the past. The following U. S. patents are representative of packages using plastic overwraps of various types. Most of these disclosures are directed to various transparent film-type non-foamed shrink wrap packages and to the use of prescribed handles, fingerholds and related supporting structures. The patents are: 3,532,214; 3,650,394; 3,331,503; 3,198,327; 3,650,395; 3,302,784; 3,552,559; 3,817,373; 3,477,564; 3,834,525; 3,416,288; 3,756,397; RE 28,535; 3,747,749; 3,217,874; Multi-container packages which utilize transparent thermoplastic films are suitable for many applications; however, their use for packaging glass containers which contain light-sensitive comestibles such as beer is undesirable.Also such films do not provide the desired level of impact protection for a multi-pack of glass containers. Further, such films can be decorated with advertising information only with difficulty requiring the use of supplemental labels or wrappers for product indentification.

The use of foamed polystyrene for shrink wrapping of multi-pack integral packages is disclosed in U.S. Patent 3,400,810. However, the foamed polystyrene taught by this patent is biaxially oriented and will shrink generally uniformly in both directions.

This type of overwrap in heat-shrunken condition exhibits generally the same strength properties in both directions, thus making expedient removal of the individual containers somewhat difficult. With this material, it is also difficult to form end seals of the flaps at the package ends due to both axial and circumferential shrinkage of the overwrap.

Summary of the invention Accordingly, it is an object of this invention to provide an improved tubular sleeve for assemblying bottles into packages for most convenient handling, shipment and use.

Another object is to provide an improved tubular preform comprised of resilient heat-shrinkable thermoplastic material adapted to telescopically surround a group of assembled bottles to form an integral package upon shrinking for convenient handling and shipment Another object is to provide an improved flexible heat-shrinkable tubular sleeve which is pre-oriented in both its circumferential and axial directions adapted to unique manufacture and folding for its convenient shipment and subsequent use in assemblying machines designed to open the sleeve and place the same telescopically around a group of bottles to form an integral package.The sleeve upon shrinkage is strong and provides cushioning protection to the surrounded bottles and yet is easily opened, is opaque to light for protecting the container contents, and is capable of being preprinted with information or decoration prior to application.

Another object of this invention is to provide a preformed tubular banding material which is adapted to flat-folding with minimal overlap of its folds as well as with an axial thermal fusion seal, the sleeves being designed to be packaged and shipped in multi-unit packages for subsequent opening and application to grouped similarly-shaped containers encompassing their major exteriorly-exposed surfaces.

A further object is to provide tubular banding material formed from flexible foamed sheet thermoplastic material which is heat-shrinkable having fold lines at opposite sides and a fusion seal along a bottom portion intermediate the side fold lines, the sleeve being adapted to uniform pile-type stacking for easy opening and usage. The tubular banding material can thus be packaged flat in multi-pack units for delivery and use in conjunction with packaging machines adapted to moving spaced tightly-assembled groups of bottles through the apparatus.

The tubular preformed sleeve of this invention is thus especially adapted for use with high speed filling and capping machines to receive the filled, capped bottles issuing from such machines and form them into packages such as the conventional six-pack employed to merchandise soft drinks and beer. The bottles to be packaged are fed onto a horizontal belt conveyor in spaced groups each normally consisting of two parallel rows of three bottles each in upright side-by-side relation. The groups of bottles are carried by the conveyor past a sleeve-applying position with the groups then being telescopically deposited in individual sleeves.Adjacent the sleeve-applying position, flexible tubular sleeves are fed from a magazine in flat-folded condition, one at a time, onto an opening conveyor where they are subsequently picked up and retained by retention arms following which distention means serve to open the sleeves serially into generally rectangular configuration. The opened sleeves are then moved arcuately downwardly and along the bottle conveyor where the bottle groups are tele scoped into the tubular sleeves for deposition centrally therewithin. The sleeves containing the assem bled bottles are then conveyed through a heat shrinking tunnel oven where the sleeves are heat shrunk tightly around the grouped bottles. The sleeves are shrunken to a considerable extent around the major exposed surfaces of the bottles leaving only portions of the end bottles of the group slightly exposed.

The tubular sleeves of the present invention comprise a plastic overwrap which is opaque, pre stretched and oriented, laminated composite mate rial. The sleeves are primarily oriented in a circum ferential direction and constitute a closed cellular, foamed, thermoplastic, polyolefin layer laminated to a non-cellular thermoplastic polyolefin film. The sleeves in heat shrunken condition circumscribe the assembled containers and snugly engage the tops of containers in shrink-fit relation.

An essential feature of the present invention is the compacted structure of a heat-shrinkable polymeric sleeve which is formed of composite sheet material having a layer of closed cellular foamed olefin polymer adhered to a layer of non-cellular olefin polymer film wherein the cellular layer is located on the inside of the sleeve adapted to engage with at least the tops and closures of the containers and the film is on the outside of the sleeve having a smooth glossy decorated surface. A basic form of the invention is presently disclosed and claimed in co-pending U. S. Patent Application Serial No.

694,267, filed June 9, 1976, in the name of James E.

Heider, entitled, "Merchandising Package for Containers," which application is owned by the same assignee as the present application, and this invention constitutes an improvementthereover. The disclosure of the above-identified application is incorporated herein by reference.

Further objects and advantages of the present invention will be apparent from the following detailed specification and reference to the accompanying drawings.

Brief description of the drawings Figure 1 is a schematic perspective view of the tubular sleeve manufacturing process and resultant folded sleeves.

With reference to the drawings, a sheet of thermoplastic material having the aforesaid characteristics is taken as a blank 1 to be formed into a tubular sleeve 2. The sleeve 2 has a uniform wall thickness and is preferably comprised of a laminated polymeric olefinic thermoplastic material such as polyethylene. The composite material has one surface comprised of a layer of a closed-cell foamed olefin polymer firmly adhered to a non-cellular olefin polymeric film. The cellularfoamed layer is preferably on the inside of the sleeve 2a and the noncellular film layer is preferably on the outside of the sleeve 2b presenting a smooth non-porous surface especially adapted to decorating.The laminated composite material is impervious to air, light and water and has a primary orientation in a circumferential direction when formed into a tubular sleeve. The material has a secondary orientation in the axial direction when formed into a sleeve. The composite material in sheet form has a bulk density ranging from about 2 to 30 pounds per cubic foot and particularly desirable tensile strength for practicing the present invention. The laminated foamed and film sheet should have an overall thickness preferably ranging from about 0.004 to 0.020 inch.

The tubular sleeve is formed from a pre-stretched and oriented lengthy sheet or ribbon of cellular and non-cellular olefinic thermoplastic material which is preprinted or decorated on the smooth film side. The primary orientation of the material extends in major amount along the longitudinal or axial direction of the lengthy sheet or ribbon, and preferably has a shrinkage of about 70% as formed. The sheet has a substantially-lesser shrinkage ranging from about 10 to 20% in the transverse direction or across the sheet as formed.

The lengthy ribbon or web of printed sheet material is normally wrapped into rolls for subse quent use. The printed rolls are sized to a prescribed width which is equivalent to the desired axial length of the tubular preform to surround the assembled bottles with the requisite end overhang. Thus the sheet or ribbon of oriented preprinted stock having its primary orientation extending continuously in the lengthwise or machine direction is taken as the starting material. The sheet in roll form is delivered onto a drum where the sheet is severed into uniform lengths of prescribed width or axial dimensions. The length is slightly greater than the desired circumferential or radial dimension to loosely surround the assembled bottles transversely of the rows.

The blanks which are normally cut in succession from a roll are placed on individual mandrels and wound thereon and seamed by overlapping the trailing marginal end of the blank over its leading marginal end. The blank ends are united at the overlapped region by fusion, adhesion or other known methods to form a sleeve or tube of the material comprising a tubular preform. A preferred method of forming the seam 2c consists of locally heating the two overlapped portions of material resting in physical engagement, contacting the area with a pressure-applying heated seal bar, and with such heat and pressure forming a lineal fusion or heat seal.

The seam 2c may also be formed by an adhesive compatible with the sheet material. The seam extends continuously and uniformly throughout the axial length of the sleeve as formed. The overlapped ends of sleeve employed to form the seam are devoid of printing and decoration so that no intermediate material will adversely affect seam formation.

The newly-formed sleeve or tube is then flattened into collapsed condition by the use of gusseted side folds 2d formed in the sleeve sides. The juxtaposed sides of the sleeve are moved inwardly to form axially-extending pleats or gusset folds with their centerfold being near the central region of the sleeve sides. Thus three axial fold lines are employed to fold each side upon itself with the middle fold projecting inwardly. The side folds are formed so that the bottom portion 2e of the sleeve is formed having a substantially-greater width than the top portion 2f. Both top and bottom panels are rectangularly shaped with the parallel fold lines defining the edges of the top panel residing inwardly of the fold lines defining the bottom panel. Thus the folds comprising the side folds 2d do not overlie one another with the sleeve in initially-flattened condition.The fold lines are such that they do not detract from the exterior appearance of the sleeve after opening and application to the assembled bottles.

After the side folds are formed as aforesaid, the top panel is folded near a central region 2g perpendicularto the sleeve axis. The transverse fold is made substantially off-center so that the open end edges of the sleeve are spaced apart a substantial distance to facilitate easy opening of the sleeve.

The seam 2c preferably resides in a central bottom region of the flattened sleeve with the side folds on both sides thereof. The doubly-folded sleeves are readily adapted to being packaged in multiple unit boxes, trays or envelopes containing a substantial number of similarly-folded and aligned sleeves, the number being 200 to 500 per box, tray or envelope, for example.

The sleeve being formed of flexible laminated foam and film thermoplastic material is adaptable to withdrawal one-by-one from the multi-pack tray or box. The material being flexible permits its being readily opened into tubularform for introduction of the assembled bottles. The sleeve can be initially opened by various methods, such as by freeing the shorter folded portion of the outermost sleeve and pulling the sleeve from the pile-type stack by such free end.

The sleeve thus folded is especially valuable for feeding one at a time to a sleeve-applying machine.

The fold lines of the tubular preform are preferably made by passing the preform through nip rolls 3 to flatten it; however, other methods may also be used such as pressing between flat plates. The sleeve is adapted to easy opening such as by diametricallydisposed vacuum cups just prior to its enclosing a group of bottles telescopically.

In a preferred form of the invention, the sleeve has a length of about 1 1'2 inches and the top panel is folded having a width of about 58 inches, with the bottom panel being about 68 inches wide. The center fold is made with about one inch offset so that the end edges are disposed substantially apart. This sleeve is especially valuable for surrounding a six-bottle group of standard size and shape nonreturnable 12-ounce beer bottles for heat-shrinking into tight conformity. Only small equi-sized openings exist at the ends of the final package when the bottles are centrally located in tangential contact. No movement of individual bottles occurs within the package after heat-shrinking the sleeve therearound.

The tubular sleeve results in no waste at the sleeve-applying station of a packaging machine. Its usage in multipack units provides an economical wrap for application by such machines with little or no downtime to exchange or replace rolls of banding or labeling material. As desired, the sleeves may be produced at a centralized location and shipped to many smaller operations to be expediously opened and applied to the selected containers.

Various modifications may be resorted to within the spirit and scope of the present invention as defined by the appended claims.

Claims (14)

1. A tubular preform article for use in packaging a plurality of similar containers in tightly-held array, said preform article being comprised of heat shrinkableflexiblefoamed opaque thermoplastic material of uniform wall thickness which is prestretched and oriented in both its circumferential and axial directions to facilitate substantial heatshrinkage upon usage, the improvement comprising a thermal fusion seal extending throughout the axial dimension of said tubular preform article, a decorative pattern imprinted on the exterior surfaces of said preform article except in the area of said thermal fusion seal, a pair of pleated side folds disposed along the sides of said preform article to flatten said article, and an off-center transverse fold wherein the top panel is folded on itself to place said article in doublefolded flattened condition for pile-type stacking.

2. A tubular preform article in accordance with Claim 1, wherein the thermal fusion seal is disposed in the bottom panel of said preform article.

3. A tubular preform article in accordance with Claim 1, wherein said pair of pleated side folds is comprised of inwardly and axially-extending gusseted folds with their central folds located near the centers of the article side panels.

4. A tubular preform article in accordance with Claim 1, wherein said pleated side folds are formed so that the bottom panel has a substantially greater width than the top panel for improved stacking and easy opening.

5. A tubular preform article in accordance with Claim 1, wherein said preform article is comprised of foamed polyethylene sheet having a thickness ranging from about 0.004 to 0.020 inch.

6. A tubular preform article in accordance with Claim 1, wherein said off-center transverse fold in the top panel is formed so that the flattened open-end edges of said article are disposed substantially apart.

7. A tubular preform article in accordance with Claim 1, wherein the several folds and fusion seal are properly aligned to permit double flat-folding of the article with minimal overlap of said folds and thermal fusion seal for improved stacking and dispensing of a pile-type stack of said articles.

8. A tubular preform article for packaging a plurality of similar containers such as glass bottles and the like in tightly-held tangential array, said preform article being formed from a lengthy sheet of foamed thermoplastic material which is flexible, opaque and heat-shrinkable as well as being prestretched and oriented in both its circumferential and axial dimensions to facilitate substantial heatshrinkage upon usage, the improvement comprising an axially-extending thermal fusion seal disposed in the bottom portion of said preform article;; a decorative pattern imprinted on the exterior surfaces of said preform article except in the area of said axially-extending thermal fusion seal, a pair of similar parallel gusseted side folds disposed along the juxtaposed sides of said preform article to flatten the same, said side folds forming a rectangular top panel which is substantially narrowerthan a rectangular bottom panel, and an off-center transverse fold wherein the top panel is folded on itself to place said article in doublefolded flattened condition especially adapted to uniform pile-type stacking for ease of shipment and use.

9. Atubular preform article in accordance with Claim 8, wherein said pair of gusseted side folds are formed by folding the exterior surfaces of the sides inwardly into face-to-face pleated relation along off-center axial lines to flatten the said article.

10. A tubular preform article in accordance with Claim 8, wherein said preform article is comprised of foamed polyethylene sheet having a thickness of not less than about 0.004 inch.

11. A tubular preform article in accordance with Claim 8, wherein the said thermal fusion seal, gusseted side folds and top panel transverse fold are aligned to minimize overlapping when the article is double-folded to facilitate uniform stacking of a plurality of said preform articles and one-by-one dispensing of same from a pile-type stack.

12. Atubular preform article substantially as hereinbefore described with reference to the drawing.

New claims or amendements to claims filed 25th April 1980 Superseded claims New or amended claims:

13. A tubular open-ended preform article for use in packaging a plurality of similar containers in tightly-held array, said preform article having a top, a bottom and sides extending between said top and bottom and being comprised of heat-shrinkable flexible foamed opaque thermoplastic material of uniform wall thickness which is pre-stretched and oriented in both its circumferential and axial directions to facilitate substantial heat-shrinkage upon usage, the improvement comprising a thermal fusion seal joining opposite sides of a sheet of said thermoplastic material to form a tube in which the opposite ends thereof are open, said seal extending throughout the axial dimension of said tubular preform article, a decorative pattern imprinted on the exterior surfaces of said preform article except in the area of said thermal fusion seal; a single pleated side fold disposed along each side of said preform article to flatten said article, said pleated side folds being longitudinally symmetrical with respect to the longitudinal axis of said preform article and forming top and bottom panels wherein said top panel is substantially narrower than said bottom panel;; said side folds and fusion seal being arranged in said preform article such that said side folds and fusion seal do not overlap and are substantially spaced from each other as viewed in cross-section when said preform article is flattened, and an off-center transverse fold wherein the top panel is folded on itself such that said opposite open-end edges are disposed substantially apart to place said article in double-folded flattened condition; whereby the height of a stack of said tubular articles is minimal and said preform articles may be more easily dispensed from said stack and opened.

14. Atubularopen-ended preform article for packaging a plurality of similar containers such as glass bottles and the like in tightly-held tangential array, said preform article having a top, a bottom and sides extending between said top and bottom and being formed from a lengthy sheet of foamed thermoplastic material which is flexible, opaque and heat-shrinkable as well as being pre-stretched and oriented in both its circumferential and axial dimensions to facilitate substantial heat-shrinkage upon usage, the improvement comprising an axially-extending thermal fusion seal joining the opposite ends of said sheet to form a tube in which the opposite ends thereof are open, said seal being disposed in the bottom portion of said preform article, a decorative pattern imprinted on the exterior surfaces of said preform article except in the area of said axially-extending thermal fusion seal, a single gusseted side fold disposed along each side of said preform article to flatten the same, said side folds being longitudinally symmetrical with respect to the longitudinal axis of said preform article and forming rectangular top and bottom panels wherein said top panel is substantially narrower than said bottom panel, said side folds and fusion seal being arranged in said preform article such that said side folds and fusion seal do not overlap and are substantially spaced from each other as viewed in cross-section when said preform article is flattened, and an off-center transverse fold wherein the top panel is folded on itself such that said opposite open-end edges are disposed substantially apart to place said article in double-folded flattened condition especially adapted to uniform pile-type stacking for ease of shipment and use.