ADAPTABLE PACKAGING MACHINE HEAT SHRINK TUNNEL

Abstract: A shrink tunnel (100) for use with packaging machines utilizing heat shrinkable film (17). Air plenums (158, 160, 162, 164) positioned in the shrink tunnel (100) accurately direct heat at laterally opposed ends (188, 190, 198, 200, 202, 204, 206, 208, 212, 214, 218, 220) of film wrapped packages (192, 194, 196, 210, 216, 222) to shrink film into a bullseye (19). The air plenums (158, 160, 162, 164) are adjustable to accommodate different size packages or a differing number of lanes of operation. Interior air plenums (160, 162) are inserted between packages in lanes of a multiple lane packaging machine so that the laterally opposed ends of all packages have hot air directed at them.

Description: ADAPTABLE PACKAGING MACHINE HEAT SHRINK TUNNEL Field of the Invention This invention relates to an adaptable shrink tunnel that directly applies hot air to specific portions of heat shrinkable film in a packaging machine wherein articles packaged in heat shrinkable film are produced in alternative modes of operation of the packaging machine including single lane, dual lane and triple lane. Background of the Invention The packaging of consumer and wholesale goods in heat shrinkable film is well known, the properties of the film allowing it to be wrapped around articles before shrinking and thereafter to be shrunk by applying heat to bring the film into tight engagement with the articles to form the package. One particular use of heat shrinkable film in packaging is in the secondary packaging of cylindrical articles such as bottles or cans of foods, soups, beverages, etc. The secondary packaging of articles such as bottles or cans generally includes a first step of arranging the articles into a group that will eventually form a multi-pack. In many instances, the articles are enclosed in a tray, although such enclosure in a tray is not necessary and does not distinguish the prior art from the present invention. It is well known that film wrapped around a group of articles, whether in a tray or not, may be heated to shrink the film and bring it into tight engagement with the articles to form a finished multi-pack. In a typical operation of a packaging machine incorporating heat shrinkable film, the film is wrapped around the articles and, if included, the tray enclosing the articles, until there is an overlap seam of the two ends of the film. The overlap seam is then sealed to form a tube around the group of articles, the tube open at both ends. Application of heat shrinks the tube of film to create small, generally elliptical openings, known as bullseyes, at the laterally opposed ends of the multi-packs where the tube openings had been prior to shrinkage. To improve the appearance and integrity of packages, it is desirable to control the application of heat to the film in such a manner that the shrinkage is uniform and results in bullseyes that are uniformly shaped and properly positioned at the laterally opposed ends of the multi- pack. A development in the shrink wrap packaging of articles incorporates the use of heat shrinkable film with letters, numbers, logos, etc., imprinted on the film. If the shrinkage of the film is not precisely controlled, any printing (letters, numbers, logos, etc.) on the film will be distorted and the package will be unattractive. If anything imprinted on the film is to be machine read and used for automatic processing of the package, such as a bar code, non-uniform shrinkage that distorts the imprinted matter negatively affects the further processing and handling of the package. In addition, if the shrinkage is not controlled and the bullseye is not properly formed, resulting in articles that are loose or not substantially enclosed by the film after shrinkage, the integrity of the multi-pack will be at risk as it is transported and handled from wholesaler to retailer to consumer. In prior art packaging machines it has been common to shrink the film by passing the film wrapped group of articles through a shrink tunnel or chamber wherein the ambient air temperature is sufficiently high and the dwell time sufficiently long to shrink the film into tight engagement with the group of articles. Non uniformity and an inability to control the shrinking of the film are the predictable results of such ambient air heating. It has become known that controlled application of hot air directed at the tube openings at the ends of a film wrapped group of articles gives more control over the shrinkage of the film and results in improved uniformity of the bullseye and improved integrity of the package. As the need for packaging machines to be flexible to produce different size, orientation and arrangement of packages has developed, new problems have arisen in the heating and shrinking of film. The prior art has addressed the problem of adjustable methods and devices for controlling the application of hot air to heat shrinkable film only in a limited manner. In U.S. Patent No. 5,546,677 to Tolson, nozzles with flexible hot air ducts to accommodate different width packages are provided. Hot air is directed upwardly from below the package pass-line at the edges of the packages being processed to control the heating of the sides of the film. The position of the nozzles may be adjusted to accommodate packages of differing widths. As discussed above, a common application of heat shrinkable film to enclose a group of articles is the secondary packaging of bottles or cans, including beverages, into multi-packs of six, twelve, twenty four or other numbers of articles. The integrity and appearance of the packaging of articles such as cans or bottles into multi-packs is primarily dependent upon the integrity of the bullseyes formed in the laterally opposed ends of the packages, so the control of the formation of the bullseyes must be an important consideration in the design of a packaging machine utilizing heat shrinkable film. It has been determined that, while more controlled heating of the ends of the tube results when hot air is directed at the ends by nozzles, the exclusive use of such nozzles shrinks the ends without fully shrinking the interior areas of the packages, resulting in uneven shrinkage of the film in different areas of the package. In addition, the use of nozzles to direct hot air at a specific part of the package and film limits the machine to a specific size or arrangement of package because the nozzle has to be in a different position to accommodate different size packages. The problems associated with using hot air nozzles directed at the ends of the film tube are particularly acute in packaging machines that are alternatively operable as a single lane machine, which requires nozzles directed at two package ends, or as a dual lane machine, which requires nozzles directed at four package ends. To direct hot air at the ends of all the packages being processed it is necessary to insert and remove interior nozzles between the between the lanes that direct hot air at the interior ends of the film tubes. The necessity to insert and remove hot air nozzles to accommodate a differing number of lanes has not been previously addressed in the means . While adjustability has been addressed in the limited manner discussed above with respect to differing width packages, it has not been addressed for machines that handle a differing number of packaging lanes. It is thus desirable to design a shrink tunnel for use with film wrap packaging machines that provides for overall heating and shrinking of film in an ambient environment and also for the application of hot air directly to control heating and shrinking of film at the laterally opposed ends of the packages. To accommodate a broad range of packaging machines, it is also desirable to provide a shrink tunnel that is flexible and which can accommodate different modes of operation including single lane, dual lane, or multiple lane. While it is desirable to provide a flexible packaging machine that can process either a single lane of packages or dual or multiple lanes of packages, it becomes problematic to controllably shrink the film wrapped around multiple lanes of packages because to direct hot air at the interior ends of the packages, hot air must be supplied and delivered between lanes of packages so that uniform heat shrinkage at both laterally opposed ends of all the packages being processed occurs. Insofar as adjustable machines that can operate in a single lane mode of operation or multiple lane mode of operation have only recently been developed, as patented in U.S. Patent 5,765,336 to Neagle, the problem of alternatively heat shrinking either a single lane or multiple lanes of packages wrapped in film has gone unaddressed. There is thus identified a need for a shrink tunnel that is flexible wherein hot air is applied ambiently and directly at laterally opposed ends of packages wrapped in heat shrinkable film whether the packaging machine is operating in a single lane mode, dual lane mode, or multiple lane mode. Objects of the Invention It is an object of the present invention to provide a shrink tunnel for a packaging machine wherein heat is applied in an ambient environment for overall shrinkage of film and directly at specific portions of the tube to increase control of the shrinkage. It is another object of the present invention to provide a packaging machine having an adjustable shrink tunnel to accommodate single lane packaging, dual lane packaging or multiple lane packaging. It is another object of the present invention to provide a shrink tunnel for use with heat shrinkable film wherein the shrink tunnel has laterally adjustable plenums to accommodate differing widths of packages by applying hot air to the laterally opposed ends of packages. It is yet another object of the present invention to provide a shrink tunnel for use with a packaging machine that provides adjustable plenums to accommodate single lane packaging or multiple lane packaging. It is a further object of the present invention to provide a shrink tunnel for use with packaging machines that provides adjustable plenums to accommodate single lane packaging, dual lane packaging or multiple lane packaging modes of operation. It is a further object of the present invention to provide a shrink tunnel having an ambient hot air pre-shrink zone and a controlled heat zone that is adaptable to single lane, dual lane or multiple lane modes of operation of the packaging machine. It is yet another object of the present invention to provide a shrink tunnel providing for the controlled application of hot air directly at laterally opposed ends of packages being processed to create consistent and uniform bullseyes therein. It is another object of the present invention to provide a shrink tunnel having adjustable air plenums that control the direction and application of hot air to heat shrinkable film wrapped around groups of articles being packaged. It is a further object of the present invention to provide a packaging machine having an adjustable controlled heat zone that is adaptable to accommodate operation of an associated packaging machine in single lane or dual lane modes of operation. These and other objects and advantages of the present invention will be apparent from a review of the following specification and accompanying drawings. Summary of the Invention The present invention comprises a shrink tunnel associated with a machine for forming packages from groups of articles that are wrapped in heat shrinkable film. The shrink tunnel has multiple zones comprising an ambient air pre-shrink zone and a controlled heat zone, limited overall shrinkage of the film occurring in the pre-shrink zone so that precise control of the shrinkage occurs in the controlled heat zone by specifically directing hot air at laterally opposed ends of packages being processed. The formation of bullseyes in the laterally opposed ends of the package, from shrinkage of the open ends of a tube of heat shrinkable film formed after wrapping and lap sealing the film around the articles, is improved and made more consistent through the use of the controlled heat zone. In the most preferred embodiment of the present invention, the means for applying hot air to the laterally opposed ends of packages comprises multiple air plenums having apertures therein that are formed and positioned to direct hot air exiting therefrom at laterally opposed ends of the packages wrapped in heat shrinkable film. The shrink tunnel is adaptable to provide controlled heating and shrinking of film when operated in either single lane or dual lane modes of operation. The shrink tunnel of the present invention comprises means for adjusting the positions of air plenums that direct hot air as necessary at laterally opposed ends of film wrapped packages being processed thereby to accommodate single lane mode or dual lane mode of operation of a packaging machine. The present invention provides shrink tunnel that accommodates operation in single lane, dual lane or triple lane mode through the use of multiple air plenums that have adjustable positions within the shrink tunnel. Specifically, the air plenums are adjustable along position bars and are locked into place to accommodate the desired mode of operation. The shrink tunnel of the present invention is particularly advantageous when used with a shrink wrap packaging machine that is adjustable between single lane and dual lane modes of operation. The means for adjusting the shrink tunnel of the present invention to accommodate single lane and dual lane modes of operation is simplified and does not require complex mechanical adjustments or the addition or removal of equipment. The shrink tunnel of the present invention controls the application of hot air to heat shrinkable film, resulting in improved appearance and reliability of the finished package, but it further includes the means for adjusting those hot air application means so that, even if the packaging machine operation changes from single lane to dual lane, the same control of hot air application is retained. Brief Description of the Drawings Figure 1 is a schematic illustrating single lane packaging of cylindrical articles into a multi-pack. Figure 2 is a schematic illustrating dual lane packaging of cylindrical articles into two multi-packs. Figure 3 is a perspective view of a shrink tunnel illustrating the passage of film wrapped packages therethrough to form finished multi- packs. Figure 4 is a front schematic view of a shrink tunnel illustrating the components, zones and application of hot air to film wrapped packages processed therein. Figure 5a is a front sectional view along lines 5-5 of Figure 4 illustrating single lane mode of operation in the associated packaging machine and shrink tunnel. Figure 5b is a front sectional view along lines 5-5 of Figure 4 illustrating dual lane mode of operation in the associated packaging machine and shrink tunnel. Figure 5c is a front sectional view along lines 5-5 of Figure 4 illustrating triple lane mode of operation in the associated packaging machine and shrink tunnel. Detailed Description of the Invention Figure 1 of the drawings illustrates single lane packaging of cylindrical articles 10 to form a finished multi-pack 12. The basic steps in creating the multi-pack 12 include grouping the articles 10 at a collation section 14, forming a tray 15 around the articles 10 at trayformer section 16, wrapping the articles 10 in a tube of heat shrinkable film 17 at film wrap section 18, and applying hot air at shrink section 20. The tube of film 17 is a sheet of heat shrinkable film wrapped around articles 10 that is lap sealed as will be explained in greater detail herein and has openings at laterally opposed ends. Application of hot air to the tube of film 17 causes the openings to shrink to create smaller essentially elliptical openings known as bullseyes 19 in the laterally opposed ends of the finished multi-pack 12. While Figure 1 illustrates the use of a tray 15 around the articles 10, it is specifically contemplated that the principles of the present invention may be used with or without a tray or trayforming apparatus. Figure 2 is a schematic illustrating dual lane packaging of articles 50 to form two finished multi-packs 52, 54. In dual lane operation, articles 50 are grouped at a collation section and subsequently split into two groups and placed into trays at trayformer section 56. Tubes of heat shrinkable film are then applied at film wrap section 58. Hot air is applied at shrink section 60 to form two finished multi-packs 52,54, each having bullseyes in laterally opposed ends after shrinkage of the film. While Figure 2 illustrates the use of trays around the articles, it is specifically contemplated that the principles of the present invention may be used with or without a tray or trayforming apparatus. A machine that is adaptable to package articles in either single lane mode, as shown in Figure 1 , or in dual lane mode, as shown in Figure 2, is disclosed in U.S. Pat. No. 7,565,336 to Neagle. The means for adjusting the shrink tunnel of the present invention to accommodate single lane and dual lane modes of operation is simplified and does not require complex mechanical adjustments or the addition or removal of equipment. The shrink tunnel of the present invention controls the application of hot air to heat shrinkable film, resulting in improved appearance and reliability of the finished package, but it further includes the means for adjusting those hot air application means so that, even if the packaging machine operation changes from single lane to dual lane, the same control of hot air application is maintained. While the schematics in Figure 1 and Figure 2 show single and dual lane modes of packaging articles, the present invention comprises a shrink tunnel that can accommodate a packaging machine having three lanes or more. The applicant has developed a single shrink tunnel that is flexible and can be converted and used with packaging machines that are operable in a single lane mode of operation, a dual lane mode of operation, or a triple lane mode of operation, to produce multi-packs having consistent and uniform bullseyes formed therein, improving the integrity of the packages produced thereby. It is also specifically contemplated that the principles of the present invention may be applied to more than three lanes of operation through the addition of more air plenums, as will be discussed in more detail herein. The present invention is directed to improvements in the heating and shrinking of heat shrinkable film around multi-packs. It has been discovered that uniform shrinkage of film results from multiple stage heating of the film wherein heat is first applied in an ambient hot air environment that provides overall shrinkage of the film, followed by controlled heating of specific portions through the controlled and directed application of hot air. In a packaging machine that is convertible between single and dual lane modes of operation, it is necessary to provide flexible means for directing heat so that, when converting to change the number of lanes of operation, it is still possible to control the directed hot air to produce the uniform single lane multi-pack 12 shown in Figure 1 or the dual lane multi-packs 52, 54 shown in Figure 2. It is desirable to apply hot air directly and uniformly at the laterally opposed ends of the heat shrinkable tube of all multi-packs so that bullseyes are formed in both laterally opposed ends of packages, whether in single lane, dual lane or more multiple lane modes of operation. The shrink tunnel 100 shown generally in Figure 3 illustrates dual lane mode of operation of a packaging machine. Two multi-packs 102,104 wrapped in tubes of heat shrinkable film are shown prior to shrinkage and after shrinkage, the flow through the shrink tunnel being in the direction indicated. The tube of heat shrinkable film formed around each multi-pack 102,104 includes an overlap 106 formed in a preceding film wrap section of an associated packaging machine. After wrapping articles in heat shrinkable film, such as multi-packs 102,104, the first step in shrinking the heat shrinkable film to create a finished multi-pack is to lap seal the overlaps 106 together. The film thereafter comprises tubes around the articles being packaged that are open at both laterally opposed ends. Means for sealing the overlap 106 is provided by a blower 108 that moves air across heating elements 100 in the direction shown (Figure 4). The hot air produced thereby is directed at the film overlap 106 located under the multi-pack or multi-packs by duct 112 and lateral nozzle 114 which extends substantially all the way across the width of the shrink tunnel 100. Next, overall heating and shrinking of the tubes of film is accomplished in an ambient pre-shrink zone 120 provided in the shrink tunnel 100 wherein a blower 122 moves air across heating elements 124. Hot air produced by blower 122 and heating elements 124 is distributed within zone 120 by ductwork 126 and distribution baffle 128. While Figure 4 illustrates a single run of ductwork 126 and baffle 128, it is specifically contemplated that more elaborate means for distributing heated air in the ambient pre-shrink zone may be employed without departing from the principles of the present invention. The ambient pre-shrink zone 120 is similar to prior art shrink tunnels wherein overall shrinkage of the film tube occurs. In the ambient pre-shrink zone 120 of the present invention the temperatures and dwell times are maintained such that some limited overall shrinkage occurs without shrinking the tube of heat shrinkable film into tight engagement with the articles. The most preferred embodiment of the present invention provides a means for heating the laterally opposed ends of the packages to produce uniform bullseyes in heat shrinkable film wrapped around them. Specifically, a shrink tunnel 100 is provided with a controlled heat zone 150 in which hot air is precisely controlled and specifically directed at the laterally opposed ends of packages being processed. It is a significant feature of the present invention that the final heating and shrinkage of the film tube occurs in the controlled heat zone 120 wherein the application of hot air is more precise. Hot air used in the controlled heat zone 150 is supplied by a blower 152 which moves air across heating elements 154 and through a main duct 156. Out of main duct 156, hot air is directed to apply heat to laterally opposed ends of packages wrapped in tubes of heat shrinkable film by four air plenums 158,160,162,164 and flexible ducts 166, 168, 170, 172 in the most preferred embodiment of the present invention (Figures 5a-5c). The flexible ducts 166, 168, 170, 172 provide the flexible means for delivering hot air to multiple apertures 165 formed in the plenums 158, 160, 162, 164. The ducts 166, 168, 170, 172 are flexible and air-tight and allow the plenums 158, 160, 162, 164 to be freely adjusted to accommodate packages of different sizes, or to accommodate packaging in a single lane, dual lanes or multiple lanes. The multiple apertures 165 are formed in rows near the bottoms of the plenums 158, 160, 162, 164 to provide the means for directing hot air at the laterally opposed ends of the film tubes wrapping the packages being processed to control shrinkage of film to create bullseyes in the laterally opposed ends of the finished film wrapped packages. An intermediate distribution chamber 174 is provided between the main duct 156 and the four plenums 158, 160, 162, 164 which comprises means for shutting off air to the four plenums 158, 160, 162, 164 independently of one another depending on the number lanes and mode of operation of the associated packaging machine. Shut off valves 176, 178, 180, 182 are provided at the air exit of the distribution chamber 174 that may be closed to interrupt air flow to the plenums 158, 160, 162, 164 as necessary or desired. Means for adjusting the positions of the plenums 158, 160, 162, 164 are provided in the preferred embodiment of the present invention so that the shrink tunnel 100 is adaptable to provide controlled heating at laterally opposed sides of packages being processed when operated in single lane mode, dual lane mode or triple lane mode of operation. Specifically, the plenums 158, 160, 162, 164 are hung from and are adjustable on position bars 184, 186 that extend laterally across the expanse of the shrink tunnel 100 and which are incorporated into the structure and supported by the shrink tunnel 100. The positions of the plenums 158, 160, 162, 164 are laterally adjustable and lockable along the length of the position bars 184, 186 to accommodate single lane operation as shown in Figure 5a, dual lane operation as shown in Figure 5b, and triple lane operation as shown in Figure 5c. It is specifically contemplated that additional plenums may be added to accommodate more lanes of packaging without departing from the principles of the present invention. Single lane operation of the shrink tunnel 100 is illustrated in Figure 5a wherein the two interior plenums 160, 162 are used to apply hot air to the opposed lateral ends 188, 190 of the package 192 as shown (see Figure 5a directional arrows). The plenums 160, 162 are positioned along position bars 184, 186 to accommodate the width of a single film wrapped package 192. In single lane operation, shut off valves 176, 182 are provided as a means to cut off air to the unused outer plenums 158, 164. Figure 5b illustrates dual lane operation in the shrink tunnel 100 wherein interior plenum 162 is positioned between the two lanes represented by film wrapped packages 194, 196. The use of three plenums 160, 162, 164 provides a means for directing hot air at the laterally opposed ends 198, 200 of package 194, as well as the laterally opposed ends 202,204 of package 196. Hot air is specifically directed as shown (see Figure 5b directional arrows) at the laterally opposed ends 198,200,202,204 to create uniform bullseyes in both laterally opposed ends of both packages 194, 196 being processed in dual lane mode of operation. Interior plenum 162 is provided with bidirectional hot air supply apertures 165 (see Figure 5b) to apply hot air to the interior laterally opposed ends 202, 204 of the two packages 194, 196 being processed in dual lane mode. The presence of apertures 165 on both sides of the interior plenum 162 is a feature of the present invention allowing a packaging machine to be converted from single lane to and from dual lane modes while retaining the benefit of directly applying hot air at the laterally opposed ends of the packages for final shrinkage of the film tube. In dual lane mode, the shut off valve 176 is closed to cut off air to unused plenum 158, while the other three shut off valves 178, 180, 182 are open. In the triple lane mode of operation of the shrink tunnel 100, four air plenums 158, 160, 162, 164 provide the means to direct hot air at laterally opposed ends 206, 208 of first lane package 210, at laterally opposed ends 212, 214 of second lane package 216, and at laterally opposed ends 218, 220 of third lane package 222. Bullseyes that are consistent are thus created in the laterally opposed ends of all three packages 210, 216, 222. Both interior plenums 160, 162 are provided with bidirectional hot air supply apertures 165 on both sides to ensure controlled heating of the laterally opposed ends 208, 212, 214, 218 of the packages 210, 216, 222 being processed in triple lane mode of operation. The adjustable and lockable positions of the air plenums 158, 160, 162, 164, along with the bidirectional hot air supply apertures 165 on the interior plenums 160, 162 provide the means for adjusting the shrink tunnel to accommodate operation of a packaging machine in single lane mode, dual lane mode and triple lane mode without requiring complex mechanical adjustment or addition or removal of equipment to the machine. The air plenums 158, 160, 162, 164 provide an improved means for controlling the direction of hot air to shrink laterally opposed ends of heat shrinkable film to create repetitive and consistent bullseyes and to remove the uncertainty of relying on uniform shrinking in an ambient air environment. This improves product appearance, particularly for film with numbers, print, bar codes, logos, etc., imprinted thereon. It also improves product integrity because the likelihood of exposed and unenclosed articles resulting from uncontrolled shrinkage of the film is reduced. Providing the adjustable plenums 158, 160, 162, 164 also allows the shrink tunnel to be adapted to accommodate various configurations of a packaging machine. Specifically, the preferred embodiment of the present invention is adaptable for use in single lane, dual lane or triple lane modes of operation, although the use of more than three lanes of operation with additional adjustable plenums is specifically contemplated so that the use of adjustable, retractable or selectable air plenums to accommodate a packaging machine or shrink tunnel with more than three lanes is not a departure from the principles of the present invention. As discussed above, ambient air shrinking of the film overall occurs in the pre-shrink zone 120, but the overall shrinking is limited so that application of hot air in the controlled heat zone 150 provides the final shrinkage of the film to bring the film into tight engagement with and enclosure of the articles being packaged and to create the desired uniform bullseyes. By being positioned in the shrink tunnel downstream from the pre-shrink zone 120, the adjustable plenums 158, 160, 162, 164 provide the means for tightly controlling the shrinkage of the laterally opposed ends of film to create uniform bullseyes in the finished packages whether the packaging machine is operating in single lane, dual lane, triple lane or more multiple lanes mode. The plenums 158, 160, 162, 164 are adjusted and locked to allow the packaging machine and shrink tunnel to be utilized to process packages of differing widths. By adjusting the spacing of the plenums 158, 160, 162, 164 on the position bars 184, 186, the distance between them and the laterally opposed ends of the film can be defined to maximize the control of the heating and shrinking of the laterally opposed ends of the film. The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

Claims: I claim: 1. A shrink tunnel (100) associated with a film wrap packaging machine utilizing heat shrinkable film comprising: a pre-shrink zone (120); and a controlled heat zone (150). 2. The shrink tunnel (100) as set forth in Claim 1 wherein said pre- shrink zone (120) comprises an ambient heating environment wherein limited overall shrinkage of the heat shrinkable film occurs. 3. The shrink tunnel as set forth in Claim 2 wherein said controlled heat zone (150) comprises means (158, 160, 162, 164, 166, 168, 170, 172) for applying hot air that is precisely controlled and specifically directed at laterally opposed ends (188, 190, 198, 200, 202, 204, 206, 208, 212, 214, 218, 220) of packages being processed. 4. The shrink tunnel as set forth in Claim 3 wherein said means (158, 160, 162, 164, 166, 168, 170, 172) for applying hot air is flexible to allow said packaging machine to be operated in both single lane mode and dual lane mode. 5. The shrink tunnel as set forth in Claim 4 wherein said means (158, 160, 162, 164, 166, 168, 170, 172) for applying hot air further comprises multiple air plenums (158, 160, 162, 164) having apertures (165) therein directing hot air at said laterally opposed ends (188, 190, 198, 200, 202, 204, 206, 208, 212, 214, 218, 220) of said packages. 6. The shrink tunnel as set forth in Claim 5 further comprising means (184, 186) for adjusting positions of said air plenums (158, 160, 162, 164). 7. The shrink tunnel as set forth in Claim 6 wherein said adjusting means comprises position bars (184, 186) extending across said shrink tunnel (100). 8. The shrink tunnel as set forth in Claim 7 further comprising means for locking said air plenums into position on said position bars. 9. The shrink tunnel as set forth in Claim 8 further comprising means (184, 186) for adjustment to accommodate operation of a packaging machine in single lane mode, dual lane mode and triple lane mode. 10. A machine (100) for packaging articles into multi-packs operable in single lane and dual lane modes comprising: a film wrap section (58) wherein tubes of heat shrinkable film (17) are formed around each of said multi-packs; a heat shrink tunnel (100); and means (158, 160, 162, 164, 166, 168, 170, 172) for directing hot air at specific portions of each of said multi-packs. 11. The machine for packaging as set forth in Claim 10 wherein said means (158, 160, 162, 164, 166, 168, 170, 172) for directing hot air comprises means for directing hot air at laterally opposed ends (188, 190, 198, 200, 202, 204) of each of said tubes whether said machine is operating in single lane mode or dual lane mode. 12. The machine for packaging as set forth in Claim 11 wherein said means (158, 160, 162, 164, 166, 168, 170, 172) for directing hot air further comprises adjustable air plenums (158, 160, 162, 164) directing hot air at said laterally opposed ends (188, 190, 198, 200, 202, 204).

Inventors: MARTI JEAN, NEAGLE CLAUDE ANDREW, MARTI, JEAN, NEAGLE, CLAUDE, ANDREW
Applicants: MARTI JEAN, NEAGLE CLAUDE ANDREW, MARTI, JEAN, NEAGLE, CLAUDE, ANDREW
Application year: 2001
Main classification: B65B53
IPC codes: B65B53