Apparatus for joining overlapped side edges of plastic film sheet formed into elongate tube

Abstract

A joining apparatus and methods wherein, after plastic film is formed into a variable size tube for receiving therein and enveloping corresponding variable size large articles such as bales of cotton, trash, cloth, etc., the joining apparatus joins an overlap region of the plastic film tube for effectively sealing and creating the plastic film tube. The joining apparatus includes an inner shoe located inside the formed tube. The overlap region slides over the inside shoe as the tube is formed. An outside shoe is moveable between an idle position away from and an operative position adjacent to the inside shoe. When in its operative position, the overlap region is sandwiched between the outside and inside shoes and heated air is provided under pressure through a groove on the outside shoe and onto the overlap region for effectively heating and joining the overlapped plastic sheets.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of packaging machines and, more particularly, to packaging machines that utilize a plastic film directed from a plastic film roll to envelop and package a variable sized article. More particularly, the present invention relates to a joining apparatus and methods wherein, after the plastic film is formed into a variable size tube for wrapping or enveloping corresponding variable size large articles such as bales of cotton, trash, cloth, etc., the joining apparatus joins an overlap region of the plastic film tube for effectively sealing and creating the plastic film tube.

2. Background

It is desirable to package and/or envelop bulk materials such as insulation, trash, cloth, scraps, recyclables, etc. that have been pre-bundled into a bale with a plastic film. However, such bales are typically fairly large and, as a consequence, require large sheets/webs of plastic film capable of surrounding the bales. Additionally, such bales vary in size (length, width and height) and hence are difficult to consistently and snugly envelop in plastic film.

Numerous form, fill and seal apparatus have been developed and are in use whereby plastic film is formed into a tube and articles are inserted and enveloped therein. However, such prior apparatus are incapable or efficiently, quickly and relatively inexpensively forming a variable size plastic film tube corresponding to and adapted to snugly envelop variable size articles such as bales of insulation, trash, cloth, scraps, recyclables, etc. The prior apparatus are also incapable of efficiently, quickly and relatively inexpensively joining the overlap region of the formed tube for sealing and creating the plastic film tube.

Accordingly, a need exists for an improved apparatus for joining the overlap region of a formed plastic film tube and thereby sealing and creating a variable size plastic film tube corresponding to and adapted to snugly envelop variable size articles.

SUMMARY OF THE INVENTION

In one form thereof the present invention is directed to a joining apparatus used in an apparatus for forming elongate film into a tube around articles, the forming apparatus including: a conveying surface adapted to carry the articles being wrapped; a forming collar adapted to wrap film around the articles carried on the conveying surface, the forming collar including left and right sections, the left section located adjacent a left side of the conveying surface and the right section located adjacent a right side of the conveying surface; wherein the left and right forming collar sections each include an inside surface, an outside surface and a leading edge; wherein elongate film having a central area and left and right sides is formed into a tube by directing: the central film area onto the conveying surface; the left film side along the forming collar left section outside surface, around its leading edge and along its inside surface; and, the right film side along the forming collar right section outside surface, around its leading edge and along its inside surface; wherein the formed tube includes an elongate overlap region whereat the left film side is arranged adjacent to and overlapping the right film side, the elongate overlap region extending longitudinally along the formed tube with one of the left or right film sides being on the inside of the formed tube and the other of the left or right film sides being on the outside of the formed tube. The apparatus for joining the left and right film sides to one another at the overlap region includes an outside shoe adapted to be located outside the formed tube adjacent the overlap region and an inside shoe adapted to be located inside the formed tube adjacent the overlap region whereby the overlap region may be sandwiched between the outside and inside shoes. Hot air is selectively directed to the overlap region whereby the first and second plastic film sheets are heated and joined to one another.

Preferably the outside shoe includes a face adapted to slidingly engage the plastic film overlap region and an air delivery groove extending into the outside shoe from a delivery groove opening in the face. The hot air is selectively provided under pressure into the groove and exits through the air delivery opening whereby the hot air is directed onto the plastic film overlap region. The groove is elongate and extends in the longitudinal direction of the formed tube. The elongate groove has an ingress end closest to the forming collar and an egress end opposite the ingress end. The inside shoe includes an inside shoe face adapted to slidingly engage the plastic film overlap region and an inside groove extending into the inside shoe from the inside face. The inside groove is elongate and extends in the longitudinal direction of the formed tube. The inside elongate groove has an ingress end closest to the forming collar and an egress end opposite the ingress end. The inside groove is adapted to be located adjacent to and facing the outside shoe groove with the plastic film overlap region therebetween.

Yet more preferably, an outside roller is located adjacent the outer shoe groove egress end and has an outside bearing surface. An inside roller is located adjacent the inner shoe groove egress end and has an inside bearing surface. The outside bearing surface is adapted to be located adjacent to and facing the inside bearing surface with the plastic film overlap region therebetween. The outside roller bearing surface is comprised of silicone rubber.

The outside shoe is preferably selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from the plastic film overlap region. A guiding post is mounted to the outside shoe and slidingly engages a supporting mount, whereby the outside shoe is guided between its operative and idle positions. A pneumatic cylinder is connected between the outside shoe and the supporting mount and is selectively energized for moving the outside shoe between the operative and the idle positions.

An ingress roller may be located adjacent the outer shoe groove ingress end and having an outside bearing surface. The ingress roller outside bearing surface is adapted to be located adjacent to and facing the inside shoe face with the plastic film overlap region therebetween. A manifold is preferably located within the air delivery groove and has a plurality of hot air distribution holes. The hot air adapted to travel through and be distributed by the manifold along the air delivery groove. The left and right forming collar sections and the outside and inside shoes are supported on a movable carrier and the carrier is movable relative to the carrying surface.

In another form thereof, the present invention is directed to a joining apparatus used in an apparatus for forming elongate film having a central area and left and right sides into an elongate tube and wherein the formed tube includes an elongate overlap region whereat the left film side is arranged adjacent to and overlapping the right film side, the elongate overlap region extending longitudinally along the formed tube with one of the left or right film sides being on the inside of the formed tube and the other of the left or right film sides being on the outside of the formed tube. The apparatus for joining the left and right film sides to one another at the overlap region includes an outside shoe adapted to be located outside the formed tube adjacent the overlap region and an inside shoe adapted to be located inside the formed tube adjacent the overlap region, whereby the overlap region may be sandwiched between the outside and inside shoes. Hot air is selectively directed to the overlap region whereby the first and second plastic film sheets are heated and joined to one another.

Preferably, outside shoe includes a face adapted to slidingly engage the plastic film overlap region and an air delivery groove extending into the outside shoe from a delivery groove opening in the face. The hot air is selectively provided under pressure into the groove and exits through the air delivery opening whereby the hot air is directed onto the plastic film overlap region. The inside shoe includes an inside shoe face adapted to slidingly engage the plastic film overlap region and an inside groove extending into the inside shoe from the inside face. The inside groove is adapted to be located adjacent to and facing the outside shoe groove with the plastic film overlap region therebetween. The outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from the plastic film overlap region. An outside roller is located adjacent the outer shoe and has an outside bearing surface. An inside roller is located adjacent the inner shoe and has an inside bearing surface. The outside bearing surface is adapted to be located adjacent to and facing the inside bearing surface with the plastic film overlap region therebetween. A manifold is located within the air delivery groove and has a plurality of hot air distribution holes. The hot air is adapted to travel through and be distributed by the manifold along the air delivery groove.

In yet another form thereof, the present invention is directed to an apparatus for joining a first plastic film sheet and a second plastic film sheet to one another, the plastic film sheets being arranged adjacent to and overlapping one another at an overlap region. The joining apparatus includes a first shoe adapted to be located adjacent the first plastic film sheet at the overlap region and a second shoe adapted to be located adjacent to the second plastic film sheet at the overlap region, whereby the overlap region is sandwiched between the first and second shoes. Hot air is directed to the overlap region whereby the first and second plastic film sheets are joined to one another.

Preferably, the first shoe includes a face adapted to slidingly engage the plastic film overlap region and an air delivery groove extending into the first shoe from a delivery groove opening in the face. The hot air is selectively provided under pressure into the groove and exits through the air delivery opening whereby the hot air is directed onto the plastic film overlap region. The second shoe includes a second shoe face adapted to slidingly engage the plastic film overlap region and a second groove extending into the second shoe from the second face. The second groove is adapted to be located adjacent to and facing the first shoe groove with the plastic film overlap region therebetween. The first shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from the plastic film overlap region. A first roller is located adjacent the first shoe and has a first bearing surface. A second roller is located adjacent the second shoe and has a second bearing surface. The first bearing surface is adapted to be located adjacent to and facing the second bearing surface with the plastic film overlap region therebetween. A manifold is located within the air delivery groove and has a plurality of hot air distribution holes. The hot air adapted to travel through and be distributed by the manifold along the air delivery groove.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a plastic film bale wrapping machine incorporating an apparatus for unfolding folded plastic film and form it into a tube in accordance with the principles of the present invention;

FIG. 2 is a side elevation view of the machine shown in FIG. 1;

FIG. 3 is a top plan view of the machine shown in FIG. 1:

FIG. 4 is a front, left side and top perspective diagrammatic view of the film unfolding section and the tube forming section incorporated in the machine of FIG. 1 and constructed in accordance with the principles of the present invention;

FIG. 5 is a rear, right side and top perspective view of the film unfolding section and the tube forming section shown in FIG. 4;

FIG. 6 is a front, left side and bottom perspective view of the film unfolding section and the tube forming section shown in FIG. 4;

FIG. 7 is a front, right side and top perspective view of the film unfolding section and the tube forming section incorporated in the machine of FIG. 1 (with the wrapper section cantilevered conveyor removed for illustration purposes) and constructed in accordance with the principles of the present invention;

FIG. 8 is a side elevation view of the film unfolding section and the tube forming section shown in FIG. 7;

FIG. 9 is a front, right side and top perspective view of the film unfolding section and the inner form tube section shown in FIG. 7;

FIG. 10 is left side elevation view of the film unfolding section and the inner form tube section shown in FIG. 9 and diagrammatically depicting the cantilevered wrapper section conveyor and film guide plates;

FIG. 11 is a top plan view of the film unfolding section and the inner form tube section shown in FIG. 9;

FIG. 12 is a perspective view of the film wrapper/tube forming section and film unwind section constructed in accordance with the principles of the present invention;

FIG. 13 is a partial perspective view of the forming collar carriage shown in FIG. 12;

FIG. 14 is diagrammatic top plan view of the forming collar and guide plate forward triangular end with the forming collar carriage removed, and depicting the left shoulder section pivoted about its pivot assemblies and in an expanded position;

FIG. 15 is a diagrammatic side elevation view of the forming collar and showing the left shoulder section in its retracted position;

FIG. 16 is a diagrammatic side elevation view similar to FIG. 15 but showing the left shoulder section in its expanded position moved upwardly and backwardly;

FIG. 17 is a diagrammatic front elevation view of the forming collar shown in FIG. 14 depicting the left shoulder section pivoted about its pivot assemblies and in an expanded position;

FIG. 18 is another side elevation view of the machine shown in FIG. 1;

FIG. 19 is a front, right side and top perspective view of the apparatus similar to FIG. 7 and further showing a joining apparatus constructed in accordance with the principles of the present invention and mounted on the carrier;

FIG. 20 is a perspective view of the apparatus similar to FIG. 19 but showing the rear, left side and top;

FIG. 21 is a top plan view of the apparatus as shown in FIG. 19;

FIG. 22 is a rear, left side and top partial perspective view of the forming tube and joining apparatus carried on the carrier and depicting a formed plastic film tube;

FIG. 23 is a left side elevation view of the apparatus as shown in FIG. 22;

FIG. 24 is an exploded view of the apparatus shown in FIG. 22 with the joining apparatus removed;

FIG. 25 is a perspective view similar to FIG. 22 but with the forming collar removed and the outer shoe of the joining apparatus exploded;

FIG. 26 is a perspective view of the outer and inner shoes of a joining apparatus constructed in accordance with the principles of the present invention; and,

FIG. 27 is a perspective view of the outer shoe shown in FIG. 26 and showing the air delivery groove thereof.

Corresponding reference characters indicate corresponding parts throughout several views. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIGS. 1 through 3, a bale wrapping machine/apparatus is shown and generally designated by the numeral 10. Bale wrapping apparatus 10 is adapted to wrap articles 12 with plastic film which is provided on plastic film roles 14. Articles 12 can be any product, however, in the preferred embodiment are typically bales 16 of cotton, trash, insulation and other bulk materials which have previously been bound and formed into an elongate rectangular box shape as shown. Bales 16 will generally differ in size (height, width and length) and therefore, bale wrapping apparatus 10 is adapted to accommodate the different height, width and length thereof. Moreover, bales 16 are fairly large and are, for example, in the neighborhood of 21 inches high, by 33 inches wide and 55 inches long, and can weigh in the neighborhood of 500 pounds.

Bale wrapping apparatus 10 includes an infeed section 18, a wrapping section 20 and an output section 22. Bales 16 are wrapped with plastic from role 14 as they travel through the wrapping section 20 in a longitudinal direction depicted by arrow/line 21. Infeed section 18 includes a conveyor 24 whereupon bales 16 may be placed for transport towards and into the wrapping section 20. Conveyor 24 can take the form of an endless belt conveyor or, alternatively, may be a low friction surface or low friction rollers whereupon bales 16 may be placed and then slid towards and into the wrapping section 20. When conveyor 24 is a low friction surface, a ram 26 is provided as shown and selectively longitudinally driven with drive assembly 28 towards the wrapping section 24 thereby pushing the bales 16 towards and into the wrapping section 20.

After the bales 16 have been wrapped or, more particularly, inserted into a plastic film tube 47 formed in the wrapping section 20, they are moved toward the output section 22 whereat they are transported via conveyor 30. Between wrapper section 20 and output section 22, a horizontal sealing section 23 is provided whereby, at each longitudinal end of the enveloped bale, the plastic film tube 47 is sealed in a known and customary manner for thereby fully enclosing or enveloping the bale. The wrapped bales 16 may then be removed from conveyor 30 by forklift or other means and/or can be further transported with other conveyors as needed or desired.

The wrapping section 20 includes a film unwind section 32, a film unfolding section 34 and a tube forming section 36. In the embodiment as shown, the film unfolding section 34 is located vertically below the film tube forming section 36, however, these sections can be located in other orientations relative to one another.

The film unwind section 32 includes a roll support assembly 38 whereupon the plastic film rolls 14 may selectively be placed for use in the bale wrapping apparatus 10. The plastic film 40 is unwrapped from the plastic film rolls 14 and directed toward the unfolding section 34 with a plurality of guide rollers 42. In the preferred embodiment as shown, the plastic film 40 is directed to the film unfolding section 34 generally horizontally over and along the supporting surface 44.

Referring now to FIGS. 4-12, the tube forming section 36 includes a plastic film forming tube or collar 46 whereat a plastic film tube 47 is formed for receipt of the bales 16 therein. Forming tube 46 is generally made up of left and right shoulder sections 48, 50 and the upper conveyor or carrying surface 130 of the endless belt conveyor 129. Left and right shoulder sections 48, 50 are provided with left and right lead-in guides 52, 54 respectively. Forming tube 46 defines an inlet orifice 56, a central volume 57 and outlet orifice 58.

Left and right lead-in guides 52, 54 are, in part, generally conically shaped and flared outwardly away from the inlet orifice 56. Lead-in guides 52, 54 form a “chute” leading into the forming tube central volume 57 that aids to guide bales 16 into the central volume 57 of the plastic film forming tube 46. More importantly, the lead-in guides 52, 54 come in contact with the bales 16 as the bales travel into the inlet orifice 56 and cause the left and/or right shoulder sections 48, 50 to shift and selectively increase the central volume 57 and, hence, the width/size of the plastic tube 47. In this manner, the plastic film tube 47 is selectively increased or decreased in width/size for accommodating variable sized bales.

Left and right shoulder sections 48, 50 are pivotally supported with pivot assemblies 60 from a carrier 62. Pivot assemblies 60 each include an arm 61 pivotally secured at their upper end to the carrier 62 about pivot axes 62R, 62L and pivotally secured at their lower end to a shoulder section 48, 50 about pivot axes 48L, 50R. As best seen in FIG. 7, the pivot axes of each arm 61 are parallel to one another. The pivot axes of each shoulder section 48, 50 are also parallel to one another. That is, pivot axes 62R and 50R are parallel to one another and pivot axes 62L and 48L are parallel to one another. Accordingly, shoulder section 48 is movable in a direction defined by an arc that swings about the pivot axes 62L while being maintained in a generally vertical orientation by pivoting about axes 48L. Similarly, shoulder section 50 is movable in a direction defined by an arc that swings about the pivot axes 62R while being maintained in a generally vertical orientation by pivoting about axes 50R. Additionally, the pivot assemblies 60 allow the left and right shoulder sections 48, 50 to be independently selectively moveable relative to each other. A tension spring mechanism 51 (FIG. 7) is secured between the left and right shoulder sections 48, 50 for biasing the shoulder sections 48, 50 towards each other and, hence, upon or in sliding engagement with bales 16 as the bales 16 travel through the central volume 57 of the forming tube 46.

As shown in FIG. 12, cam assemblies 138 are provided whereby the carrier 62 is itself also capable of moving vertically upwardly and backwardly away from the conveyor upper surface 130. Cam assemblies 138 include cam slots 140 on the supporting horizontal beams 142 of the wrapper section frame 144. Cam slots 140 are formed between cam rails 141 affixed to the beams 142. Cam slots 140 are sized and adapted to slidingly receive cam roller wheels 146 which are pivotally secured to the carrier 62 with bolts 143. Accordingly, cam roller wheels 146 along with the carrier 62 and the complete forming tube assembly 46 are moveable relative to the wrapper frame 144 in a direction depicted by arrow 148 at an angle α with respect to the horizontal surface 44 and the longitudinal line 21. Left tension spring mechanism 63L is secured between the frame 144 and the left shoulder section 48 and right tension spring mechanism 63R is secured between the frame 144 and the right shoulder section 50 (FIGS. 3 and 12). Left and right tension spring mechanisms 63L, 63R independently bias the left and right shoulder sections 48, 50 respectively downwardly relative to the frame 144 and, hence, upon or in sliding engagement with bales 16 as the bales 16 travel through the central volume 57 of the forming tube 46.

The independent movement of left and right shoulder sections 48, 50 via the pivot assemblies 60 in combination with the movement of the carrier 62 via the cam assemblies 138, as more fully discussed herein below, allows variable size bales 16 to be received through the forming tube 46 and also forms the plastic film tube 47 having a size/circumference as needed for a snug fit around the bales regardless of the bale size.

Left and right form tube shoulder sections 48, 50 include left and right inner form tube sections 86, 88 respectively. The inner form tube sections 86, 88 are each supported on a frame formed by an upper beam member 85, side beam member 87 and rear connecting plate member 89. The upper beam members 85 are pivotally secured to arms 61 at pivot axes 50R, 48L. The lead-in guides 52, 54 are secured to the forward end of beam members 85, 87, whereas the rear connecting members 89 are secured to the rear end of the beam members 85, 87 and to the inner form tube sections 86, 88. Hence, the left and right inner form tube sections 86, 88 are affixed to and supported by the frame members 85, 87 and 89 in the left and right form tube sections 48, 50 respectively and move as described herein above in connection with the left and right form tube sections 48, 50. As more fully described herein below, the plastic film 40 at least partially travels over the inner form tube sections 86, 88 so as to form the plastic film tube 47.

Left inner form tube section 86 includes a left lower inturned lip section 90, a left mid wall section 94 and a left upper crossover triangular section 102. Similarly, the right inner form tube section 88 includes a right lower inturned lip section 92, a right mid wall section 96 and a right upper crossover triangular section 104.

Left and right inner form tube sections 86, 88 are essentially mirror images of one another and both include a forward nosing 98, 100 and rear or trailing edges 99, 101. The rear edges 99, 101 are affixed to the rear connecting plate members 89 as described herein above for thereby supporting the inner form tube sections 89, 88 as shown. The mid wall sections 94, 96 include a tapered leading edge 94E, 96E respectively. As diagrammatically depicted and shown in FIG. 10, leading edges 94E, 96E are at an angle α with respect to the horizontal surface 44 and at the same angle α as discussed herein above in connection with the direction of travel of carrier 62. That is, leading edges 94E, 96E are parallel with the direction of travel of carrier 62 as depicted by arrow 148.

The upper crossover triangular section 102 includes a leading edge 102E terminating at a rear termination point 106. Similarly, the upper crossover triangular section 104 includes a leading edge 104E terminating at a rear termination point 108. The upper crossover triangular sections 102, 104 overlap one another as shown at the overlap area 110 and, more particularly, section 104 and its termination point 108 are located above/over section 102 and its termination point 106. As further described herein below, this overlap allows the plastic film edge 126 to be placed over the plastic film edge 128 for heat sealing purposes and forming the plastic film tube 47.

Mid wall section 94 defines an exterior surface 96X and an interior surface 96I. Similarly, mid wall section 96 defines an exterior surface 96X and an interior surface 96I. Left upper crossover triangular section 102 defines an exterior surface 102X and an interior surface 102I. Similarly, right upper crossover triangular section 104 defines an exterior surface 104X and an interior surface 104I.

The film unfolding section 34 is located immediately below the plastic film forming tube 46 and conveyor 129. Film unfolding section 34 includes a guide plate 64 that is generally parallel with the upper conveying surface 130 of conveyor 129. Guide plate 64 includes left and right side edges 66, 68 that are curved upwardly and define upturned lips 66L, 68R respectively. Guide plate 64 also includes a forward triangular shaped end 70 and rear end 71. Forward end 70 includes left and right angular edges 72, 74 that are joined at a forward terminal point 76. Left angular edge 72 is joined with left side edge 66 and right angular edge 74 is joined with right side edge 68. Forward terminal point 76 is rounded or may additionally include a barb 78 that extends downwardly and between the longitudinally extending rollers 114, 115. Left and right side edges 66, 68 are parallel to one another and to the longitudinal line 21. Left and right angular edges 72, 74, as best seen in FIGS. 7 and 11, are at an angle β with respect to the longitudinal line 21. Additionally, angular edge 72 is parallel with pivot axes 50R, 62R of right pivot assemblies 60 and perpendicular with the pivot axes 48L, 62L of the left pivot assemblies 60. Angular edge 74 is parallel with pivot axes 48L, 62L of left pivot assemblies 60 and perpendicular with the pivot axes 50R, 62R of the right pivot assemblies 60.

A second or vertical guide plate 80 extends vertically upwardly and generally perpendicular to the guide plate 64. Vertical plate 80 includes a first lower edge 82, a second upper edge 84 and vertical side edges 80L and 80R. The left side edge 80L is adjacent the nosing 98 of left inner form tube section 86 and the right edge 80R is adjacent the nosing 100 of right inner from tube section 88. Lower edge 82 is adjacent to and can be affixed to the guide plate 64. Upper edge 84 includes a backwardly extending lip 84B that is curved towards the upper conveying surface 130 of conveyor 129. Lower edge 82 includes a forwardly extending lip 82F that is curved towards the forward triangular shaped end 70 of guide plate 64. As best seen in FIG. 10, triangular end 70 can be affixed or integrally formed with the vertical plate 80 and joined at the forwardly extending lip 82F.

An elongate guide member or roller 118 is located adjacent to the vertical plate member 80 and the forward end 70 of guide plate 64. Preferably, the outer diameter of roller 118 is substantially the same as the curvature of the forwardly extending lip 82F and lip 82F partially surrounds the roller 118 as best seen in FIG. 10. However, the outside surface 118S of roller 118 is sufficiently spaced from the guide plate forward end 70, the lip 82F and the vertical plate 80 such that plastic film 40 can readily and easily travel therebetween. Roller 118 is adapted to and rotates about axis 118A. Elongate guide member 118 is substantially perpendicular to the longitudinally extending rollers 114, 115 and the guide plate side edges 66, 68.

The longitudinally extending elongate guide members or roller 114 and 115 are parallel to one another and are located vertically below and adjacent the guide plate 64. The exterior surfaces 114S and 115S of rollers 114 and 115 respectively are spaced from each other so as to form an elongate slot 112 having a width such that plastic film 40 can readily and easily travel therethrough and between the roller 114, 155. Barb 78 of the guide plate 64 extends downwardly between roller 114, 115 and to the elongate slot 115 as best seen in FIG. 9. Rollers 114, 115 are adapted to rotate about their longitudinal axes 114A, 115A respectively. Additionally, rollers 114, 115 are substantially parallel with left and right side edges 66, 68 of the guide plate 64 and have a longitudinal length which is greater than the width W of the folded plastic film 40 on the plastic film roll 14.

A longitudinally extending elongate guide member or roller 116 is located below rollers 114, 155 and is substantially parallel therewith. Guide roller 116 is adapted to rotate about longitudinal axis 116A and has an exterior surface 116S. Roller 116, similar to rollers 114, 115, has a longitudinal length which is greater than the width W of the folded plastic film 40 on the film roll 14. As shown in FIGS. 6 and 12, lower guide roller 116 is located vertically directly below one of the rollers 114, 115 with its exterior surface 116A vertically below and aligned with the elongate slot 112.

Referring now more particularly to FIGS. 4-6, the conveyor 129 is located immediately above guide plate 64 and below the plastic film forming tube 46. That is, conveyer 129 is generally sandwiched between the guide plate 64 and the forming tube 46. Conveyor 129, as mentioned herein above, includes a conveying surface 130. Conveyor 129 further includes a receiving end 132 and an outlet end 134. Receiving end 132 is adjacent the inlet orifice 56 and outlet end 134 is adjacent the outlet orifice 58. In the preferred embodiment as mentioned herein above, conveying surface 130 is provided on an endless belt conveyor 129; however, conveying surface 130 can be any low-friction surface whereupon the plastic film 40 and bales 16 can easily be traversed.

Wrapper section conveyer 129, guide plate 64 and vertical plate 80 are mounted on the frame 144 of the wrapper section 20 in a cantilever fashion. As shown diagrammatically in FIG. 10 and in the perspective view of the wrapper section in FIG. 12, horizontal cantilever beams 150 are provided on both sides of the conveyor 129 and are affixed, at their rear ends 152, to the frame 144. The beams forward ends 154 are therefore cantilevered from and extend out from the frame 144 as best depicted in FIG. 10. The vertical plate 80 is affixed to the forward ends 154 of the beams 150. The guide plate 64 is also affixed to the beams forward ends 154 such as with fasteners 156. The conveyor 129 is supported on and between the beams 150 with the conveyor receiving end 132 adjacent the beams forward ends 154 and the conveyor outlet end 134 adjacent the beams rear ends 152. As should now be appreciated, the conveyor receiving end 132, vertical plate 80 and guide plate 64 are cantilevered and extend between the forming collar 46 and the longitudinal rollers 114, 115 and 116. Hence, the plastic film 40 can be delivered from the rolls 14 normal to the longitudinal (the direction of travel of bales 16) of the apparatus 10 and underneath the film unfolding section 34 and tube forming section 36.

As best depicted in FIGS. 3-6, the plastic film 40 is provided on rolls 14 in a folded configuration wherein the overall folded width of the film/web is depicted by the letter W. In its folded configuration, plastic film or web 40 includes first and second sides 120, 122 joined along a longitudinal folded edge 124. As shown in FIG. 6, first plastic film side 120 has an outer or first longitudinal edge 126 and second plastic film side 122 has an outer or second longitudinal edge 128, and the two sides 120, 122 are joined along the longitudinal folded edge 124. The first and second sides 120, 122 are equal in size and have a width WS substantially equal to the plastic film roll width W. The width WS of each plastic film side 120, 122 is the distance between their respective outer first and second longitudinal edges 126, 128 and the longitudinal folded edge 124. Therefore, the overall total width of the plastic film/web 40 is two times that of the roll width W.

In operation, for unfolding the folded plastic film or web 40 as it is provided from roll 14 and forming it into a plastic film tube 47, the folded plastic film 40 is unwound from the roll 14 and is first delivered or travels around the guide roller 116 and up through the longitudinal slot 112 between the guide rollers 114, 115. The first plastic film side 120 then travels around the longitudinal guide roller 115 towards the right side edge 68 and the right angular edge 74 of guide plate 64. Similarly, the second plastic film side 122 travels around the longitudinal guide roller 114 towards the left side edge 66 and the left angular edge 72 of guide plate 64.

The part of the plastic film side 120 that travels to and slides around the guide plate side edge 68 (the “plastic film longitudinal right side”) then travels generally vertically upwardly towards the right inner forming tube section 88; slides over the mid wall exterior surface 96X and the right crossover triangular section exterior surface 104X; around the tapered leading edges 96E and 104E of mid wall 96 and crossover triangular section 104 respectively; and, finally, along the mid wall interior surface 96I and the right crossover triangular section interior surface 104I. Similarly, the part of the plastic film side 122 that travels to and slides around the guide plate side edge 66 (the “plastic film longitudinal left side”) then travels generally vertically upwardly towards the right inner forming tube section 86; slides over the mid wall exterior surface 94X and the right crossover triangular section exterior surface 102X; around the tapered leading edges 94E and 102E of mid wall 94 and crossover triangular section 102 respectively; and, finally, along the mid wall interior surface 94I and the right crossover triangular section interior surface 102I.

Because the triangular section 104 is above and overlaps the triangular section 102 at overlap area 110, as the plastic film tube 47 is formed, the outer longitudinal edge 126 of the plastic film side 120 is located on top of the longitudinal edge 128 of the plastic film side 122 and, hence, on the exterior of the formed plastic tube 47. Essentially, part of the first plastic film side 120 adjacent its longitudinal edge 126 overlaps part of the second plastic film side 122 adjacent its longitudinal edge 128 creating an elongate overlap region 200 having a width W_O defined by the distance between edges 126, 128 and running the length of the formed plastic film tube 47 beyond the rear edges 99, 101 of the left and right inner form tube sections 86, 88 respectively. As best seen in FIG. 4, in the overlap region 200, the plastic film side 122 is “underneath” plastic film side 120 and on the “inside” of the formed tube 47, whereas plastic film side 120 is “on top” of plastic film side 122 and on the “outside” of the formed tube 47.

The part of the plastic film side 120 adjacent the folded edge 124 that travels over the right angular edge 74 and the plastic film side 122 adjacent the folded edge 124 that travels over the left angular edge 72 (the “plastic film longitudinal middle section”), as best seen in FIG. 4, then travels: over the top of the guide plate forward triangular end 70: around the guide roller 118; vertically upwardly along the vertical plate 89; over the vertical plate upper edge 84; and, finally, onto the conveyor surface 130 of conveyor 129. It is noted that the longitudinal folded edge 124 travels: through the elongate slot 112 between guide rollers 114, 115; over the barb 78 at the guide plate forward terminal point 76; over the top and at the center of the guide plate forward triangular end 70: around the guide roller 118; vertically upwardly and along the vertical plate 89; over the vertical plate upper edge 84; and, finally, onto about the center of the conveyor surface 130 of conveyor 129.

As should now be appreciated, the plastic film tube 47 is thus formed by the plastic film longitudinal middle section traveling along the conveyor surface 130, the plastic film longitudinal left side traveling along the interior surfaces of the left inner form tube section 86 and the plastic film longitudinal right side traveling along the interior surfaces of the right inner form tube section 88. Additionally, as bales 16 are received through the forming tube inlet orifice 56, they traverse onto the plastic film longitudinal middle section over the conveyor surface 130 and into the central cavity 57 whereby they are enveloped within the plastic film tube 47. The plastic film overlapping edges 120, 122 are then heat sealed longitudinally along the overlapping region 200 using the joining apparatus 202 as more fully described herein below, and the tube 47 is cut and sealed between individual bales with sealing section 23 for individually sealing each bale 16.

Advantageously, as should now also be appreciated, the left and right forming collar shoulder sections 48, 50 pivot about their respective pivot assemblies 60 and slide vertically upwardly and backwardly along the cam assemblies 138 for thereby receiving and wrapping variable sized bales 16 and for accommodating and wrapping bales which are not centered left/right on the conveyor surface 130. More particularly, the forming collar 46, in its retracted position as shown in FIGS. 4-11, will produce its smallest size plastic tube 47 defined by the size of the inner form tube sections 86, 88 and conveying surface 130. However, as best shown in FIGS. 14-17, the forming tube shoulder sections 48, 50 and their inner form tube sections 86, 88 pivot about their respective pivot assemblies 60 and slide vertically upwardly and backwardly along the cam assemblies 138 to expanded positions dictated by the size of the bales 16 and their left/right position on the conveyor surface for thereby forming an appropriate larger size plastic tube that will fit snugly on the bale 16.

As shown in FIGS. 14 and 17, when a larger bale 16 or a bale which is, for example, located more toward the left side of the conveyor comes in contact with the lead-in guide 52, the left collar shoulder section 48 will pivot about its pivot assemblies 60 and travel upwardly and backwardly in a direction depicted by arrow 158. The direction of arrow 158 is ideally parallel to the left angular edge 72 of the guide plate forward triangular shape 70 and also parallel to the left inner forming collar leading edge 94E, and the pivot assemblies 60 and length of arms 61 are adapted to produce movement of the left shoulder section approximately, but not exactly, in the direction of arrow 158. Accordingly, shoulder section 48 will move backwardly a distance B and a corresponding vertical distance V and a leftward horizontal distance H, and the plastic tube 47 that will be formed over the bale will correspond thereto and fit snugly thereon. The right shoulder section 50, as described hereinabove, will move independent of shoulder section 48 about its pivot assemblies 60 causing shoulder section 50 to similarly move by a bale 16 contacting its lead-in guide 54 a vertical distance V but a rightward horizontal distance H. Therefore, with both shoulder sections 48, 50 in their maximum expanded positions as a result of pivoting about pivot assemblies 60, the forming collar/tube 46 will form a plastic tube 47 and accommodate a bale having a width equal to the forming collar retracted position width plus twice the horizontal distance H and a height equal to the forming collar height plus the vertical distance V.

So as to accommodate bales which are yet taller in height, as described hereinabove, both shoulder sections 48, 50 are pivotally supported with their respective pivot assemblies 60 on the common carriage 62 which is itself moveable vertically upwardly and backwardly along the cam assemblies 138. More particularly, as best seen in FIGS. 15 and 16 wherein the left and right shoulder sections are shown not pivoted about their pivot assemblies 60, in their retracted positions the shoulder sections 48, 50 are relatively close to conveyor surface 130 (FIG. 15). However, when a taller bale 16 comes in contact with one or both the lead-in guides 52, 54, the carriage 62 along with both the left and right collar shoulder sections 48, 50 will slide and travel via the cam assemblies 138 upwardly and backwardly in a direction depicted by arrow 148. Accordingly, carrier 62 and shoulder section 48, 50 will move backwardly a distance B2 and vertically upwardly a distance V2, and the plastic tube 47 that will be formed over the bale will correspond thereto and fit snugly thereon. Therefore, with both shoulder sections 48, 50 not pivoted about their pivot assemblies 60, in their maximum expanded positions as a result of the carriage traveling along the cam assemblies 138, the forming collar/tube 46 will form a plastic tube 47 and accommodate a bale having a height equal to the forming collar retracted position height plus a vertical distance of V2.

Finally, with both shoulder sections 48, 50 in their maximum expanded positions as a result of pivoting about pivot assemblies 60 as well as a result of the carriage traveling along the cam assemblies 138, the forming collar/tube 46 will form a plastic tube 47 and accommodate a bale having a width equal to the forming collar retracted position width plus twice the horizontal distance H and a height equal to the forming collar height plus the vertical distances V and V2.

Referring now more particularly to FIGS. 18-27, there is shown and generally designated by the 202 a sealing or joining apparatus which heat seals/joins the first or right plastic film side 120 with the second or left plastic film side 122 longitudinally along the overlap region 200 as the plastic film tube 47 exits the forming tube 46 from the outlet orifice 58 and is traveling in the longitudinal direction indicated by arrow 204 in FIG. 4. Joining apparatus 202 includes an upper or outside shoe generally designated by the numeral 206 which is supported on a supporting frame or mount 210. Joining apparatus 202 also includes a lower or inside shoe 208 which is supported on the supporting frame or mount 210. As shown and more fully described herein below, outside shoe 206 is adapted to be located outside the formed tube 47 adjacent the overlap region 200, and the inside shoe 208 is adapted to be located inside the formed tube 47 adjacent the overlap region 200 and underneath or facing the outside shoe 206 and with the overlap region 200 sandwiched therebetween. Frame 210 is affixed to and is carried by carrier 62 and, accordingly, frame 210 and the outside and inside shoes 206, 208 are adapted to move or travel with carrier 62, as described hereinabove, in the direction indicated by arrow 148. Therefore, because the left and right inner form tube sections 86, 88 are also affixed to and carried by carrier 62, shoes 206, 208 remain fixed relative to the left and right inner form tube sections 86, 88 and, hence, also remain fixed relative to the plastic film tube 47 and overlap region 200 as the plastic film tube 47 leaves the form tube sections 86, 88 and travels in the longitudinal direction 204 along with the bales 16.

As best seen in FIGS. 22-25, the lower shoe 208 is affixed to and supported on the frame 210 using a lower supporting plate 212 and an upper supporting plate 214 which are affixed to the frame 210. The left and right upper crossover triangular sections 102, 104 of the left and right inner form tube sections 86, 88 extend over and on top of the supporting plates 212, 214. Accordingly, as the plastic film tube 47 is formed as described hereinabove, the first or right plastic film side 120 and its longitudinal edge 126 and the second or left plastic film side 122 and its longitudinal edge 128 forming the elongate overlap region 200 are located on top of the upper supporting plate 214. The lower shoe 208 hence is “inside” the plastic film tube 47 as it is being formed and travels in the longitudinal direction 204. As should now be appreciated, the overlap region 200 is supported on and, as the plastic film tube 47 is formed, slides over the upper supporting plate 214 in the longitudinal direction 204.

Inside shoe 208 preferably includes an insert 216 that can be made of a high temperature resistant insulating material and which is supported by the lower and upper supporting plates 212, 214. Shoe 208 has an inside face 218 and the upper supporting plate 214 has an inside face 220. The plastic film sides and overlapping region 200 slide over and are supported on the inside faces 218, 220. A groove or opening 222 is formed and extends into the inside shoe 208 from the face 218. Groove 222 is preferably elongate shaped extending longitudinally in the longitudinal direction 204 of the plastic film tube 47. Groove 222 has an ingress end 224 closest to the forming collar 46 and whereat the plastic film approaches the groove 222. Groove 222 includes an egress end 226 longitudinally opposite the ingress end 224. An inside roller 228 is mounted in the shoe 208 at the egress end 226 of the groove 222. Inside roller 228 is adapted to freely rotate about its axis of rotation 230 which is perpendicular to the longitudinal direction 204. Inside roller 228 is preferably made of steel or other suitable hard material and has an inside annular bearing surface 232 which projects above the face 218 of the shoe 208 and effectively comes in contact with the inside face of the overlap region 200, namely, plastic film side 122.

The outside shoe 206 is affixed to and supported on the extension 234 of frame 210 so as to be located over and generally on top of inside shoe 208. Outside shoe 206 preferably comprises a mount or body portion 236 made of steel or other suitable hard material and an air distribution portion 238 made of a high temperature resistant insulating material. An air delivery groove or opening 240 is formed and extends into the air distribution portion 238 from an opening 241 through the shoe face 242. Face 242 is adapted to slidingly engage the outside face of the overlap region 200, namely, plastic film side 120. Groove 240 is preferably elongate shaped extending longitudinally in the longitudinal direction 204 of the plastic film tube 47. Groove 240 has an ingress end 244 closest to the forming collar 46 and whereat the plastic film approaches the groove 240. Groove 240 includes an egress end 246 longitudinally opposite the ingress end 244.

An air heater 248 is provided and preferably carried on the outside shoe 206. Pressurized air is provided via a conduit (not shown) to the air heater inlet 250 and is then selectively heated by heater 248 to a temperature sufficient to melt the plastic film 40. The outlet end 252 of heater 248 is fluidly connected to the outside shoe air delivery groove 240 via an air conduit 254. Accordingly, pressurized hot air is selectively provided into the groove 240 and exits through the opening 241 of face 242 whereby the hot air may be directed onto the plastic file overlap region 200. Preferably, a manifold or perforated face 256 is provided within the air delivery groove 240 and includes a plurality of air distribution holes 258 whereby the pressurized hot air is evenly distributed along the longitudinal length of the groove 240 and then through the opening 241 in face 242.

An outside roller 260 is mounted on the body portion 236 of the outside shoe 206 at the egress end 246 of the air delivery groove 240. Outside roller 260 is adapted to freely rotate about its axis of rotation 262 which is perpendicular to the longitudinal direction 204. Outside roller 260 is preferably made of steel or other suitable hard material and also has an outside annular bearing surface 264 made of silicone rubber. The bearing surface 264 projects below or out of the face 242 of the shoe 206 and effectively comes in contact with the outside face of the overlap region 200, namely, plastic film side 120. When outside shoe 206 is placed adjacent the overlap region 200 with face 242 in sliding engagement therewith, the outside bearing surface 264 of outside roller 260 is adapted to be located adjacent to and facing the bearing surface 232 of inside roller 228 and with the plastic film overlap region sandwiched therebetween. Moreover, because bearing surface 232 projects above face 218 of inside shoe 208 and bearing surface 264 projects below face 242 of outside shoe 206, the plastic film therebetween is “pinched” or effectively compressed or squeezed therebetween.

An ingress roller 266 is mounted on the body portion 236 of the outside shoe 206 at the ingress end 244 of the air delivery groove 240. Ingress roller 266 is adapted to freely rotate about its axis of rotation 268 which is perpendicular to the longitudinal direction 204. Ingress roller 266 is preferably made of steel or other suitable hard material and has an outside annular bearing surface 270. The bearing surface 270 projects below or out of the face 242 of the shoe 206 and effectively comes in contact with the outside face of the overlap region 200, namely, plastic film side 120. When outside shoe 206 is placed adjacent the overlap region 200 with face 242 in sliding engagement therewith, the outside bearing surface 270 of ingress roller 266 is adapted to be located adjacent to and facing the inside face 218 of inside shoe 208 and with the plastic film overlap region 200 sandwiched therebetween. Moreover, because bearing surface 270 projects below face 242 of outside shoe 206, the plastic film sandwiched between it and the inside face 218 is effectively compressed or squeezed therebetween such that plastic film sheets 120, 122 are retained relative to one another and prevented from planar slipping.

Outside shoe 206 is selectively moveable between: an operative position wherein its face 242 is adjacent to and overlaying the plastic sheets overlapping region 200 such that the overlapping region is sandwiched between the faces 218, 242; and, an idle position wherein its face 242 is a distance away from the plastic sheets overlapping region 200. When outside shoe 206 is in its operative position, faces 218, 242 are adjacent to and facing each other with the plastic film region 200 sandwiched therebetween, and grooves 222, 240 are adjacent to and facing each other with the plastic film region 200 sandwiched therebetween. As can be appreciated, while in the operative position, hot air may selectively be delivered through the air delivery groove 240 and opening 241 of face 242 onto the overlap region 200 whereby the plastic film sheet sides 120, 122 can effectively be heated and welded or melted together. Hence, as the plastic film tube 47 is being formed and travels in the longitudinal direction 204, outside shoe 206 may be placed in its operative position and pressurized heated air delivered onto the overlap region 200 for continuously sealing/welding the plastic film sides 120, 122 to one another and forming the sealed plastic tube 47. During the welding process, the longitudinal grooves 222, 240 allow the heated plastic film to expand as needed and, thereafter, when the heated plastic film travels to and is pinched between the bearing surfaces 232, 264 of rollers 228, 260, the melted film sheets are compressed and effectively joined to one another. As will be appreciated by one skilled in the art, the volume of pressurized air being delivered, the temperature of the heated air and the speed at which the formed tube 47 and overlap region 200 travel through the joining apparatus 202 are varied so that the plastic film sheets will be sufficiently heated to melt and bond to one another but not so hot that the integrity of the plastic film will be lost and/or destroyed.

In this regard, in the idle position, the outside shoe 206 is located a distance away from the plastic film region 200 so that any residual heat and/or hot air exiting the air delivery groove 240 will not be delivered to the plastic film. As should be appreciated, outside shoe 206 is selectively placed in the idle position, for example, when the plastic film tube 47 is not being formed or is otherwise not moving in the longitudinal direction 204.

So as to move outside shoe 206 between its operative and idle positions, a pair of guiding posts 272 are affixed to the body portion 236, parallel to one another and extending upwardly therefrom. Each of the guiding posts 272 are slidingly received through bearing members 274 which are mounted to the frame extension 234 of the supporting frame 210. Accordingly, outside shoe 206 is maintained in a position generally parallel to the inside shoe 208 while it is guided between its operative and idle positions.

A pneumatic cylinder 276 is provided and is connected between the outside shoe 206 and the frame extension 234. More particularly, the plunger rod 278 of the pneumatic cylinder is secured to the outside shoe 206 and its body 280 is secured to the frame extension 234. Accordingly, by selectively energizing pneumatic cylinder 276 and causing its plunger rod 278 to travel upwardly or downwardly, the outside shoe 206 is selectively moveable between its operative and idle positions.

While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

Claims

1. In an apparatus for forming elongate film into a tube around articles, the forming apparatus including: a conveying surface adapted to carry the articles being wrapped; a forming collar adapted to wrap film around the articles carried on said conveying surface, said forming collar including left and right sections, said left section located adjacent a left side of said conveying surface and said right section located adjacent a right side of said conveying surface; wherein said left and right forming collar sections each include an inside surface, an outside surface and a leading edge; wherein elongate film having a central area and left and right sides is formed into a tube by directing: the central film area onto said conveying surface; the left film side along said forming collar left section outside surface, around its leading edge and along its inside surface; and, the right film side along said forming collar right section outside surface, around its leading edge and along its inside surface; wherein the formed tube includes an elongate overlap region whereat the left film side is arranged adjacent to and overlapping the right film side, the elongate overlap region extending longitudinally along the formed tube with one of the left or right film sides being on the inside of the formed tube and the other of the left or right film sides being on the outside of the formed tube; an apparatus for joining the left and right film sides to one another at said overlap region, said joining apparatus comprising:an outside shoe adapted to be located outside the formed tube adjacent the overlap region and an inside shoe adapted to be located inside the formed tube adjacent the overlap region, whereby the overlap region may be sandwiched between said outside and inside shoes; and,wherein hot air is selectively directed to the overlap region and whereby the first and second plastic film sheets are heated and joined to one another.

2. The apparatus of claim 1 wherein said outside shoe includes a face adapted to slidingly engage the plastic film overlap region and an air delivery groove extending into said outside shoe from a delivery groove opening in said face, wherein said hot air is selectively provided under pressure into said groove and exits through said air delivery opening whereby said hot air is directed onto said plastic film overlap region.

3. The apparatus of claim 2 wherein said groove is elongate and extends in the longitudinal direction of the formed tube, said elongate groove having an ingress end closest to said forming collar and an egress end opposite said ingress end.

4. The apparatus of claim 3 wherein said inside shoe includes an inside shoe face adapted to slidingly engage the plastic film overlap region and an inside groove extending into the inside shoe from said inside face, wherein said inside groove is elongate and extends in the longitudinal direction of the formed tube, said inside elongate groove having an ingress end closest to said forming collar and an egress end opposite said ingress end, and wherein said inside groove is adapted to be located adjacent to and facing said outside shoe groove with the plastic film overlap region therebetween.

5. The apparatus of claim 4 further comprising: an outside roller located adjacent said outer shoe groove egress end and having an outside bearing surface;an inside roller located adjacent said inner shoe groove egress end and having an inside bearing surface; and,wherein said outside bearing surface is adapted to be located adjacent to and facing said inside bearing surface with the plastic film overlap region therebetween.

6. The apparatus of claim 5 wherein said outside roller bearing surface is comprised of silicone rubber.

7. The apparatus of claim 5 wherein said outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

8. The apparatus of claim 7 further comprising a guiding post mounted to said outside shoe and slidingly engaging a supporting mount, whereby said outside shoe is guided between its operative and idle positions.

9. The apparatus of claim 8 further comprising a pneumatic cylinder connected between said outside shoe and said supporting mount and selectively energized for moving said outside shoe between said operative and said idle positions.

10. The apparatus of claim 5 further comprising an ingress roller located adjacent said outer shoe groove ingress end and having an outside bearing surface and wherein said ingress roller outside bearing surface is adapted to be located adjacent to and facing said inside shoe face with the plastic film overlap region therebetween.

11. The apparatus of claim 5 further comprising a manifold located within said air delivery groove and having a plurality of hot air distribution holes, said hot air adapted to travel through and be distributed by said manifold along said air delivery groove.

12. The apparatus of claim 5 wherein said left and right forming collar sections and said outside and inside shoes are supported on a movable carrier and said carrier is movable relative to said carrying surface.

13. The apparatus of claim 1 further comprising: an outside roller located adjacent said outer shoe and having an outside bearing surface;an inside roller located adjacent said inner shoe and having an inside bearing surface; and,wherein said outside bearing surface is adapted to be located adjacent to and facing said inside bearing surface with the plastic film overlap region therebetween.

14. The apparatus of claim 13 wherein said outside roller bearing surface is comprised of silicone rubber.

15. The apparatus of claim 13 wherein said outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

16. The apparatus of claim 15 wherein said left and right forming collar sections and said outside and inside shoes are supported on a movable carrier and said carrier is movable relative to said carrying surface.

17. The apparatus of claim 1 wherein said outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

18. The apparatus of claim 17 wherein said left and right forming collar sections and said outside and inside shoes are supported on a movable carrier and said carrier is movable relative to said carrying surface.

19. The apparatus of claim 1 wherein said left and right forming collar sections and said outside and inside shoes are supported on a movable carrier and said carrier is movable relative to said carrying surface.

20. The apparatus of claim 2 further comprising a manifold located within said air delivery groove and having a plurality of hot air distribution holes, said hot air adapted to travel through and be distributed by said manifold along said air delivery groove.

21. In an apparatus for forming elongate film having a central area and left and right sides into an elongate tube and wherein the formed tube includes an elongate overlap region whereat the left film side is arranged adjacent to and overlapping the right film side, the elongate overlap region extending longitudinally along the formed tube with one of the left or right film sides being on the inside of the formed tube and the other of the left or right film sides being on the outside of the formed tube; an apparatus for joining the left and right film sides to one another at said overlap region, said joining apparatus comprising:an outside shoe adapted to be located outside the formed tube adjacent the overlap region and an inside shoe adapted to be located inside the formed tube adjacent the overlap region, whereby the overlap region may be sandwiched between said outside and inside shoes; and,wherein hot air is selectively directed to the overlap region and whereby the first and second plastic film sheets are heated and joined to one another.

22. The apparatus of claim 21 wherein said outside shoe includes a face adapted to slidingly engage the plastic film overlap region and an air delivery groove extending into said outside shoe from a delivery groove opening in said face, wherein said hot air is selectively provided under pressure into said groove and exits through said air delivery opening whereby said hot air is directed onto said plastic film overlap region.

23. The apparatus of claim 22 wherein said inside shoe includes an inside shoe face adapted to slidingly engage the plastic film overlap region and an inside groove extending into the inside shoe from said inside face, and wherein said inside groove is adapted to be located adjacent to and facing said outside shoe groove with the plastic film overlap region therebetween.

24. The apparatus of claim 23 wherein said outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

25. The apparatus of claim 23 further comprising: an outside roller located adjacent said outer shoe and having an outside bearing surface;an inside roller located adjacent said inner shoe and having an inside bearing surface; and,wherein said outside bearing surface is adapted to be located adjacent to and facing said inside bearing surface with the plastic film overlap region therebetween.

26. The apparatus of claim 22 further comprising a manifold located within said air delivery groove and having a plurality of hot air distribution holes, said hot air adapted to travel through and be distributed by said manifold along said air delivery groove.

27. The apparatus of claim 21 wherein said outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

28. The apparatus of claim 21 further comprising: an outside roller located adjacent said outer shoe and having an outside bearing surface;an inside roller located adjacent said inner shoe and having an inside bearing surface; and,wherein said outside bearing surface is adapted to be located adjacent to and facing said inside bearing surface with the plastic film overlap region therebetween.

29. An apparatus for joining a first plastic film sheet and a second plastic film sheet to one another, the plastic film sheets being arranged adjacent to and overlapping one another at an overlap region, said apparatus comprising: a first shoe adapted to be located adjacent the first plastic film sheet at the overlap region and a second shoe adapted to be located adjacent to the second plastic film sheet at the overlap region, whereby the overlap region is sandwiched between said first and second shoes; and,wherein hot air is directed to said overlap region and whereby the first and second plastic film sheets are joined to one another.

30. The apparatus of claim 29 wherein said first shoe includes a face adapted to slidingly engage the plastic film overlap region and an air delivery groove extending into said first shoe from a delivery groove opening in said face, wherein said hot air is selectively provided under pressure into said groove and exits through said air delivery opening whereby said hot air is directed onto said plastic film overlap region.

31. The apparatus of claim 30 wherein said second shoe includes a second shoe face adapted to slidingly engage the plastic film overlap region and a second groove extending into the second shoe from said second face, and wherein said second groove is adapted to be located adjacent to and facing said first shoe groove with the plastic film overlap region therebetween.

32. The apparatus of claim 31 wherein said first shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

33. The apparatus of claim 31 further comprising: a first roller located adjacent said first shoe and having a first bearing surface;a second roller located adjacent said second shoe and having a second bearing surface; and,wherein said first bearing surface is adapted to be located adjacent to and facing said second bearing surface with the plastic film overlap region therebetween.

34. The apparatus of claim 30 further comprising a manifold located within said air delivery groove and having a plurality of hot air distribution holes, said hot air adapted to travel through and be distributed by said manifold along said air delivery groove.

35. The apparatus of claim 29 wherein said outside shoe is selectively moveable between an operative position adjacent the plastic film overlap region and an idle position away from said plastic film overlap region.

36. The apparatus of claim 29 further comprising: a first roller located adjacent said first shoe and having an first bearing surface;a second roller located adjacent said second shoe and having an second bearing surface; and,wherein said first bearing surface is adapted to be located adjacent to and facing said second bearing surface with the plastic film overlap region therebetween.