Apparatus for wicket-top converting of a cross-laminated synthetic resin fiber mesh bag

A cross-laminated synthetic resin fabric mesh material is formed into wicket-top produce bags for use with automatic bag filling equipment. A longitudinally moving sheet of the mesh is folded and formed into a folded, gusseted tubular web. Laterally spaced holes for wicket pin attachment and slots are formed at selected positions along the length of the moving web according to the desired bag height. A wicket-top attachment is then formed on the web near the wicket pin holes. The web is then cut into bag length sleeves, which are thereafter closed at an opposite end to form the bag.

FIELD OF THE INVENTION 
The present invention relates to forming or making of wicket-top produce 
bags of cross-laminated synthetic resin fibers. 
BACKGROUND OF THE INVENTION 
So far as is known, tubular bags for holding produce for shipment and 
storage of produce have typically been made of polyethylene. The 
polyethylene bags are formed from film sheets or bands of relatively 
impermeable synthetic resin. The polyethylene bags have thus tended to 
retain moisture in with the produce contents. The retention of moisture in 
polyethylene bags accelerated the risk of spoilage of the produce in the 
bags. The polyethylene films could be perforated to allow moisture 
evaporation and air entry. However, the strength of the polyethylene was 
materially affected as the number of perforations increased. Further, due 
to the forming techniques used, polyethylene bags had side edge seams 
joining two layers of a polyethylene sheet extending upwardly from a lower 
transverse fold in the sheet. The retention or holding strength of the 
polyethylene bags was thus also limited by the strength of the side edge 
seams. 
Recently, a woven fabric of cross-laminated synthetic resin fibers known as 
Cross Laminated Airy Fabric sold under the trademark CLAF.RTM. has been 
introduced by Amoco Fabrics & Fibers, Inc. This fabric is an open mesh 
material of cross-laminated warp and weft strands or fibers of synthetic 
resin. The CLAF.RTM. cross-laminated fiber material has adequate strength 
for transport and storage of produce. Also, because of the relatively 
large mesh or spacing of the warp and weft fibers, there was no moisture 
retention problem as with polyethylene films. However, the CLAF.RTM. 
cross-laminated fiber material was not suitable for forming into bags with 
techniques like those used with polyethylene films. The spaced strands at 
edges of the materials could not be heat sealed together with adequate 
holding strength for produce bag purposes. 
BRIEF SUMMARY OF THE INVENTION 
Briefly, the present invention forms wicket-top produce bags from 
cross-laminated synthetic resin fiber material mesh, such as CLAF.RTM. 
cross-laminated fiber material or the like. The bags are formed by 
advancing or passing a sheet of the synthetic resin fiber mesh from a 
container or storage reel through a gussetting system and a folding system 
to produce a tubular web configuration. After the web has been gusseted 
and overlap folded, it is moved longitudinally to a sealing station, where 
the overlapped side edge portions of the folded material are sealed 
together in a longitudinal direction to form a tubular bag structure. 
If desired, after the sealing station, the tubular web may pass through to 
a print band applicator station. At such an applicator station, a printed 
strip or band of a suitable laminated material, which has been printed to 
display product advertising and bag length registration marking, is 
applied over sealed side edges of the tubular web. 
The now-sealed tubular web structure passes to a punch and slitter station, 
which punches laterally spaced wicket holes across the tubular web and 
forms web slots adjacent the wicket holes for wicket-top converting. The 
wicket holes and web slots allow use of the bags in automatic bag-filling 
machines, providing for wicket-top waste removal and automatic filled bag 
removal. 
The tubular web next advances to a wicket attachment station of the present 
invention. The wicket attachment station of the present invention includes 
a set of servo driven nips that creates a controlled tension in the 
longitudinally moving web, and an internal bag opening plate that then 
separates upper and lower layers of the tubular web. A cutter, such as a 
razor knife, thus has access to slit the upper web material layer without 
damage to the lower web material layer. 
After the wicket top is formed in the longitudinally moving tubular web, 
the web is cut into bag length sleeves. The sleeves are then closed 
together at an opposite end from the wicket top to form bags.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
To fully appreciate the nature of the present invention, an understanding 
of the prior art invention shown in FIGS. 1 and 2 is useful. Referring to 
FIG. 1, the prior art polyethylene bag converting process begins with an 
unwind stand 10 supporting a storage reel 11 of polyethylene lay flat 
material 12 of suitable width which is continuously fed from the top of 
the reel 11 downwardly into a web folder 14. The web folder 14 folds the 
incoming web 12 in about 1/2 of its lay flat width by advancing the web 12 
downwardly around a reel 13 then advancing it upwardly. A continuous 
motion web drive nip 16 supplies the power needed to advance the web 12 
through the web folder station 14. The web drive nip 16 also isolates the 
continuous feed upstream process from the downstream intermittent feed 
process as the web 18 leaves the web folder 14. The folded web 18 then 
passes under a hole punch assembly 20 which punches longitudinally spaced 
holes in the web 18 at a predetermined spacing so that the web can be hung 
on wicket pins of automatic bag filing equipment. The punched web 22 is 
now drawn intermittently by a servo-driven rubber nip assembly 24 toward a 
heated sealing member such as a V-shaped heated seal bar 26. The V-shaped 
heated seal bar 26 comes in contact with a lower rubber-covered seal roll 
28 during the non-draw portion of the servo nip 24 cycle, providing a 
surface for the web 22 as the heated bar 26 cross-seals the leading 30 and 
trailing 32 edges of the polyethylene web 22. The seal bar 26 then severs 
the web 22 at these edges 30 and 32. Due to the feeding direction D of the 
web 22, the leading 30 and trailing 32 edges become the two side edges of 
the bag 34. The finished wicketed polyethylene bag 34 now drops onto a 
table 29 and is available for operator handling. 
Referring to FIGS. 2A through 2D the polyethylene web is shown at various 
stages of the prior art converting process described above. In the first 
stage, the web begins as a longitudinal moving lay flat sheeting 36 (FIG. 
2A) in feed direction D. In the second stage, the web 36 passes over a web 
folder 14 which laterally folds the web 36 approximately into half of its 
width leaving an exposed lip 38 with a width of approximately 11/2 inches 
(FIG. 2B). In the third stage, the folded web 40 passes under a hole punch 
assembly 20 which punches longitudinally aligned holes in the exposed lip 
38 at predetermined hole spacing (FIG. 2C). In the final stage, the folded 
and punched web 42 comes in contact with a heated seal bar 26 to cross 
seal the side edges 30 and 32 of the bag, which are the leading 30 and 
trailing 32 edges of the web 42, and sever the finished bag sleeve 44 at 
these edges 30 and 32 from the upstream polyethylene web (FIG. 2D). 
Turning now to the present invention, the cross-laminated synthetic resin 
fiber mesh bag converting process shown in FIG. 3 begins with a unwind 
stand 46 supporting a storage reel of cross-laminated CLAF.RTM. 
cross-laminated fiber material 48 of suitable width which advances into a 
gussetting system 50. In the gusseting system 50, the outermost side edges 
98 (FIG. 4B) of the web material 48 are folded inwardly forming gussets 
99. When the finished bag 106 (FIG. 4F) is used to hold produce, the 
gussets 99 allow the sides of the bag 106 to expand thereby adjusting to 
the load of the produce. The gusseted web 51 (FIG. 3) next passes into a 
folding system 52. The folding system 52 folds the outermost side edges 61 
(FIG. 4B) of the gusseted web 51 toward each other in an overlapping 
position 60 to produce a tubular web. A continuous web drive nip 54 (FIG. 
3) isolates the continuous feed upstream process from the downstream 
intermittent feed process. The gusseted, folded tubular web 56 then comes 
under the influence of a heated reciprocating sealing bar 58 which seals 
in a longitudinal direction the overlapping outermost side edges 61 of the 
web 56 together (FIG. 4B). 
If desired, a second unwind stand 62 (FIG. 3) supports rolls of LDPE 
laminated print band material 64 and applies that material 64 to the 
tubular web 66 (FIG. 4C) as it passes through the print band applicator 
station 62 to come under the influence of a second heated reciprocating 
sealing bar 68 (FIG. 3). The heated sealing bar 68 seals the print band 
material 64 along its outermost edges 65 to the tubular web material 66 
(FIG. 4C). When converting straight top tubular bags 120, the web 70 is 
pulled intermittently by two dual servo driven nip assemblies 72 and 74 
(FIG. 3) configured in a master 74 slave 72 relationship. When converting 
wicket-top tubular bags 116, the nip 72 is open to allow the tubular web 
70 to pass through the nip 72 without constraint. 
Next, the web 73 proceeds to an air operated punch and slitter attachment 
76 that punches the required holes 78 (FIG. 4D) and web slots 80 and 82 to 
allow for wicket-top conversion. After the web 86 exits the punch and 
slitter attachment 76, the web 86 enters the present invention wicket 
attachment 84 (FIG. 3). 
Referring to FIG. 6, a resin mesh tubular web 122 is shown within the 
present invention wicket attachment 84 which is approximately six feet 
downstream of the print band sealing bar 68. The incoming resin mesh 
tubular web 122 is advanced intermittently by the slave servo driven nips 
124 and 125 which follow the pouch machine master servo driven nip 126 in 
a predetermined relationship to allow for a controlled tension zone 
between the nip points. The tubular web 122 may be driven by either of the 
two servo nips 124 and 125 or by both nips 124 and 125. An internal bag 
opening plate 128 (FIG. 7) within the wicket attachment 84 is attached 
internally to a bag opening plate support base 130 by a thin metal ribbon 
132 and is supported by low friction idler roller assemblies 134 (FIG. 7 
and FIG. 6). The metal ribbon 132 serves to keep the bag opening plate 128 
in place. When the advancing web 122 reaches the internal bag opening 
plate 128, the plate 128 separates the tubular web 122 to allow the razor 
knife 102 to slit the upper web material 112 without damage to the lower 
web material 111. The upper clamp assembly 136 of the wicket attachment 84 
next activates in a downward motion as shown by arrow 135 during the 
non-draw portion of the servo nip 124 cycle. This is done to clamp the 
opened web 122 between the upper rubber clamp 138, the upper rubber clamp 
roll 140, and the lower internal bag opening plate 128. The razor-style 
knife 102 is then activated in the cross web direction as shown by the 
arrow 142 (FIG. 7) slitting the web 122. Once the web 122 has been slit, 
the upper clamp assembly 136 activates in an upward motion as shown by 
arrow 135 to unclamp the web 122 prior to servo nip 124 draw. The upper 
rubber clamp roll 140 is driven by the upper pouch machine servo nip roll 
144 using a set of round belting 146 as the upper servo nip roll 144 and 
the master servo driven nip 126 rotate as shown by arrows 127. The upper 
clamp roll 140 and the upper servo nip roll 144 are connected with 
multiple strips of round belting 146 which sit in grooves 145 that are 
equally spaced on the rolls 140 and 144. These strips extend between the 
rolls 140 and 144. The set of round belting 146 aids the delivery of the 
slit web 122 to a pouch machine guillotine style knife 90 (FIG. 3) for web 
separation. The bag is then drop stacked onto a table 96 for operator 
handling. As the final step, the bottom edge of the bag is closed 
preferably by sewing. 
Referring to FIGS. 4A through 4F, the cross-laminated synthetic web is 
shown at various stages of the converting process previously described. In 
the first stage, the fiber mesh web begins as lay flat sheeting 48 
longitudinally moving in the feed direction F (FIG. 4A). In the second 
stage, the web passes over the gussetting 50 and folding 52 stations. The 
gusseting station 50 produces gussets 98 that in appearance are similar to 
the letter "W" by folding the outermost side edges 99 of the lay flat web 
48 inwardly. The folding station then folds the outermost side edges 61 of 
the gusseted web toward one another into an overlap position 60 (FIG. 4B). 
In the third stage, the overlap portion of the folded web 60 comes under 
the influence of the heated reciprocating seal bar 68 which seals the 
fiber mesh material onto itself producing a tubular structure 66. While 
cross-laminated fiber strands do not cross seal together with adequate 
holding strength, the strands do seal longitudinally onto one another. 
Next, if preferred, print band material 64 is applied to the tubular 
structure 66, and the web comes under the influence of a heated 
reciprocating seal bar 68 to seal the print band material 64 along its 
outermost edges 65 to the tubular fiber mesh web 66 (FIG. 4C). 
In the fourth stage, the tubular structure 73 passes to the punch and 
slitter station 76 where laterally aligned holes 78 (FIG. 4D) are punched 
through the web 100 at predetermined spacing so that the finished bag 116 
can hang on wicket pins 114 of automatic bag filing equipment. Next, the 
fiber mesh web 100 is slit at predetermined locations forming web slots 80 
of predetermined length to allow easy tear off dispensing of a finished 
cross-laminated resin mesh wicket-top bag 116 from wicket pins 114 of 
automatic bag filling equipment. The web 100 is also slit at predetermined 
locations forming web slots 82 of predetermined length to allow for 
wicket-top waste removal (FIG. 4D). At the fifth stage, the present 
invention wicket attachment 84 powers a cutting member such as a 
razor-style knife 102 which cuts a slit 104 into and across the upper 
layer of tubular material spanning from one side edge 105 to the other 
side edge 107 (FIG. 4E). 
In the final stage, the fiber mesh tubular web 106 is advanced to a 
predetermined finished bag length 109 where the knife assembly 90 
laterally severs the tubular web 106 at a cut position 110 along the edges 
of the web slots 80 and 82 opposite the edge of the web slots 80 and 82 
where the lateral slit 104 was made by the razor-style knife 102 to form 
the bag top 108. The upper layer of tubular material 112 (FIG. 4E) can now 
be discarded. The tubular web material 106 with the upper layer 112 
removed, once bottomed is the finished wicket-top resin mesh bag 116. 
It can thus be seen that the wicket attachment 84, the cross-laminated 
synthetic resin mesh converting process and the resin mesh wicket-top bag 
116, each of the present invention, solve the problems with polyethylene 
wicketed bags and the incompatibility of cross-laminated synthetic resin 
mesh material with the converting technique for polyethylene. The porous 
membrane of the synthetic resin mesh wicket-top bag 116 permits air to 
permeate through the bag thereby preventing moisture from accumulating 
therein. The synthetic resin mesh tubular bag 116 is also able to adjust 
to the load of the produce due to its gussetting design 98 which may 
assume a shape similar to the letter "W". In addition, the present 
invention cross-laminated synthetic resin mesh wicket-top bag 106, unlike 
the polyethylene wicket-top bag permits easy tear-off dispensing for 
automatic filled bag removal by providing web slots 80 and 82, creating 
additional web portions that allow for tearing. While in the preferred 
embodiment, the web slots 80 and 82 are located between the punched holes 
78 and the side edges 148 and 150, it is contemplated that aligned slots 
in the top portion of the web material could also be produced between the 
punched holes 78 and the middle of the web. 
The present invention wicket attachment station 84 of the present invention 
opens the folded fiber mesh web 122 and slits the upper web material 112 
to facilitate the removal of the upper web material 112 and formation of 
the present invention resin mesh wicket-top 108. Because cross-laminated 
synthetic fibers do not seal together in a cross direction, the lay flat 
sheet of resin mesh material 48 is fed into the converting machinery such 
that the leading 30 or trailing 32 edge of the sheet 48 becomes the top or 
bottom edge of the fiber mesh wicket-top bag 106. With this feeding 
direction F, the cross-laminated fiber strands are sealed onto each other, 
forming a tubular web structure 66. It is also the sealing properties of 
cross-laminated synthetic resin mesh material which account for the 
folding structure of the cross-laminated synthetic web wicket-top bag 116. 
While a side edge 39 of polyethylene material is folded laterally exposing 
a lip and forming overlapped side edges 41 for cross sealing, the tubular 
structure of the cross-laminated fiber mesh bag is formed by laterally 
folding both outermost side edges 61 of the lay flat fiber mesh sheet 48 
into an overlapping position 60. 
Having described the invention above, various modifications of the 
techniques, procedures, material and equipment will be apparent to those 
in the art. It is intended that all such variations within the scope and 
spirit of the appended claims be embraced thereby.