CA2181149A1

CA2181149A1 - Flexible bag and method of making and attaching a tie

Info

Publication number: CA2181149A1
Application number: CA002181149A
Authority: CA
Inventors: Gary L. Rutledge
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-01-14
Filing date: 1995-01-11
Publication date: 1995-07-20
Also published as: JPH09510926A; EP0739271A4; WO1995019259A1; EP0739271A1; AU1679495A

Abstract

A plastic film bag (B) having a tie element (62') coated on its inner surface with an adhesive (358) between the dotted line (356) and its outer end (354). The adhesive is completely covered by a removable release strip (360). The inner end portion (62a') is permanently attached to the bag by means of a heat seal (362) or a permanent adhesive. The tie element is made by applying multiple, parallel bands of adhesive to stock material, coveting the adhesive with covet strips, and separating the web into individual rolls of web stock. Tie elements are applied to bags by moving tie element web stock along a path above a web of bag material, cutting the stock into individual elements, momentarily stopping portions of the bag material under successive tie elements, and firmly anchoring each tie element to its respective bag.

Description

218~149 wos-lls2ss r~l~m~ ~ ;79 Flexible Bag and Method of Makin~3 and Attachin~ a Tie CROSS-RFFFRF.~l~F TO RF3 ATF.T) APPLT~TION
5 This application is a ~ " ,;; ' ;. " .-in-part of q~ll j~ qTinn Serial No.
389,757, August 4, 1989, U.S. Patent No. 5,188,580, which was a ~
in-part of Serial No. 117,209, November 4, 1987, U.S. Patent No. 4,854,735, entitled "Plastic Film Bag with Integral Plastic Film Tie Element, and Associated r~l;~Li~.... Methods" which is hereby ihl~ ' by reference herein.
BAt~T~('TR-~UND OF I~TF. rNVFl~TION
The present invention relates generally to the r of plastic film bags and, in a preferred ' tnereof, more IJ~uL;~ uly provides apparatus and methods for attaching to the bags pTastic film tie elements which, as disclosed in my copending U.S. q,~1i~qtir~n serial no. 117,209, may be tied around the open tops of the bags to tightly dose them.
In the ' .; of plastic film bags it is common practice to form them, by ~ ~1 extruding plastic film in tubul_r form, flattening the film tube to form a double layer "web", forming lateral weld ITines _nd .r~,laLioll lines across the web to define the individual bags which may be '~ , separated from one another at the p~rul.~l;ol~ lines, and then laterally folding the web prior to packaging of the bags. The laterally folded film web is then typic~ly delivered to a packaging station spaced apart from the bag .

W0 95/19259 ~3 . r~ 179 forming station, at a linear receiving speed identical to the linear output speed of the bag forming station, where it is rolled or folded for packaging.
For the purpose of attaching accessories to, forming logos or heat seals on, or otherwise modifying the individual bags prior to their receipt at the 5 paclcaging station, it is ~esirable to '~, stop the web at each bag during the p r. ,. ., ~ ~ of a particular, .,I; r~ operation thereon - for example, the attachment of a plastic film tie element disclosed in U.S. application Serial No.
17,209 ill~,UI~ ' ' by reference herein.
There al-e presently two methods for effecting this necessary y stoppage of the web as each individual bag passes the, -RI.r;. -l;",.
station - neither of which is wholly ~ali;~ra~ y. First, both the bag forming station output feed portion and the packaging station input drive may be l.,1.., 'y operated in a start-stop fashion to ~Iy advance and then stop the entire folded film web section extending between these two operating 15 stations. While this is a quite logical app~oach, it - Iy slows the overaU
bag production rate - a rate which must be kept as high as possible for ,ulurllalJili~y purposes.
Second, a rather comple~c, high mass, shiftable multi-roller structure may be utilized to erlgage and '~, stop a portion of the folded 20 plastic film web between the bag forming station and the winder without slowing or U~ the output and input web travel at these portions of the ove~all bag forrning apparatus. ~[owever, this high mass roller structure must be very rapidly shifted back andl forth to stop each individual bag received thereby during the high speed bag forming process. Because of the rapidity with which the ~wo gSrl92sg 2 1 8 1 1 ~ ~ P(~ J,S'~ 179 multi-}oller structure must be '!r shifted back and forth, very high shift forces result, requiring substantial power and precision control. If the multi-roller structure is not precisely designed and adjustcd, these high shift forces can easily tear the traveling film web at one of its ~.r.,.,l;.. Iines, creating significant down time and waste in the bag r ' g process.
In view of the foregoing, it can be seen that improved apparatus and methods for r~--m~n~Drily stopping each individual bag in the film web, during its movement between the bag forming station and the winder, are needed.
It is accu~ an object of the present invention to provide such improved apparatus, methods and bag structures having integral tie elements.
SUMMA.RY OF 'i~F. INVEN~ON
In carrying out principles of the present invention, in 2 ~
with a preferred ,...l.u~l' .... ~ thereof, an in-line closure tie element attachment machine is positioned between a plastic film bag forming station, which l~, produces a folded plastic film web divided into imdividual bags by y spaced 1 r '- Iines, and a winder ' which forcibly captures the folded web at a continuous linear velocity equal to the continuous linear output velocity of the bag forming station. A web handling portion of the flexible tie element attachment machine grips the moving web, and advances it 20 toward the winder, with driven roller means including an inlet drive roller, an outlet drive roller spaced apart from the inlet drive roller toward the winder and a central drive roller positioned between the inlet and outlet drive rollers in a laterally spaced, parallel ' therewith.
Positioned beneath these three drive rollers are first and second 21 8 1 1 ~ 9j WO 95/19259 ~ F~,l/.s.,..'~ 179 ;r~ L va~uum bins, the first vacuum bin having an open upper end positioned generally between the inlet and central drive rollers, and the secondvacuum bin having an open upper end positioned generally between the central and outlet drive rollers. Vacuum pump means are connected to lower end S portions of the bins fo~- creating vacuums therein during machine operation.
As the folded web is drawn through the web handling portion of the tie element attachment machine by the three drive rollers, control means associated with the machine rotate the inlet and outlet drive rollers at continuous speeds ~ ly c~ , to the linear web output and intake speeds of the bag forming station and tlle winder ' However, the control means 1~, operate the central drive roller, preferably via a stepper motor, in a manner such that the central drive roller is sequentially stopped, ~ ' ' to a rotational drive speed higher than those of the inlet and outlet rollers, ~1PrPlP~^~ and then stopped again.
Each sequential stop-t~stop drive cycle of the stepper motor-driven central roller 1 ~ , advances the portion of the web engaged by such roller a I I ' distance so that Wll~_r ~ sections of the individual bags, to which fle~ible tie elements are to be attached, are ~u~o~ ,ly and '~, sto,oped on the central driw roller, at which time a tie element attachment portion of the machine affixes a tie element to the stopped bag.
During operation of the tie element attachment machine first and second slack portions of the advancing web are ~ positioned between the inlet and central drive rollers, and between the central and outlet driver W095/19259 ~1811~ PCT/USg5~00~79 rollers. The vacuums formed in the first and second vacuum bins exert yielding, duw~ directed forces on the first and second slack web portions, created by air pressure ~ across the web portions, pulling web portions du.... ~-lly into the bins and positively, but rather gently, holding them in 5 du..l.w~dly ectending first and second web loop, 5~
At the time the central drive roller is initially stopped, to stationarily position one of the bags for tie element attachment thereto, the first web loop is c,~,~c ~ Ionger than the second web loop. During tie element attachment to the 1~, stopped bag portion of the web, the first web loop 10 lengthens, and the second web loop shortens, within their respective vacuum bins as the inlet and outlet drive ro'~lers continue to be driven at constant rotational speeds, the outlet roller talcing slack out of the second loop while the inlet roller adds slack to the second web loop. The slac c talce-up capabi'ity provided by the t~l second loop prevents the still-running outlet drive roller from 1', imposing tension force on the web sufficient to tedr it at one of its ~ru~dliUII
iines positioned on the second loop. ~ , tne slack provided in the two web loops permits sequentia' bag stoppage without a'ltering or ., _ the , constant linear web output and intalce velocities at t'ae bag forming station and the packaging station winder ' .~Li~"l~ "
20 a very high bag production rate may be After its tie element is attached to the '~1 stopped bag, the centra' drive roller is a ' 1, held at a constant elevated speed, ~i~,rl.."~rA and then re-stopped, as previously described, to stop the next n~ih~ s71ly successive bag thereon for tie element attachment thereto. This W0 95~19259 21~ 19 r~ s ~ ~79 5~
~rotation cycle of the central drive roller takes up slack in the lengthened first loop, and adds the taken-up slack to the shortened second loop, to return the two web loops to their ori~inal length " ~ at the time the central drive roller is stopped at tne end cf its drive cycle. The rapid take-up of the slack in the first 5 loop is achieved against the yielding, du~dly directed vacuum force thereon so that the web is not torn at one of the L ' Imes in its first loop portion.
Additionally, this slack take-up and loop length 1; does not alter or interrupt the constant velocity of the web entering and e~iting tne tie demcnt attachment machine.
The control means may be adjusted to A ' for differentbag lengtns being run through ~he machine, and the vacuum bins are provided with movably adjustable front side walls to, for changes in the width of tne particular folded plastic film web upon which the individusl bags are formed.
The lengtbs of the vertically oscillating web loops within the first and second vacuum bins are _ '~, monitored by means of vertically spaced series of l,l .. ~ . b 1' ' 1 l ;' beam i and associated receivers which input loop positional i .r..., --;.... to the control means to permit ~I'L .
corrective action to be taken should either of the loops become too long or too short during machine operation.
Additionally, the 1 ~- ' ' position of each successive bag stopped on the cemlal drive roller is ~ , monitored by a unique p~rul~Liull detectio~ system which senses the position of the openable end perforation line of each bag just before the bag is stopped on the central drive roller. The l' .r.. ~i.. detection system, in a prefe~red ~...I.,)~Ii,~.. .,l thereof, wo 95/19259 2 18 1 1~ ~ F~ ,' 'C 1~9 includes a high voltage electrode member spaced horizontally apart from an insulation-housed conductor supported on a central common wall structure separating the first and second vacuum bins. The electrode is pivotably supported within the first vacuum bin and, in the event that the first web loop 5 greatly shortens, is adapted to be engaged by the shortened loop and be swung out of the first bin to prevent web tearing or separation at one of the lines.
The folded web portion a~ ua~ll;l.~, the central drive roller is routed bet~-veen the electrode and the conductor so that the web ~ r...~';(. lines 10 ~u-,c~i,;vdy pass al~el,~h.~ll. A high voltage is suitably impressed on the electrode so that as each perforation line vertically passes the electrode the electrode discharges to the conductor through the passing r r~ area, thereby energizing an associated current sensor. r,~ Of the current sensor causes it to transmit an output signal to a JlJlUl~U portion of the 15 control means indicating tne passage of another ~.r...,~;--. line past the electrode. This r " is ~ , correlated to the rotational drive of the central drive roller to ~ monitor the orientation of each individual bag stopped thereon.
In the event that the individual bags begin to be l~ y ll.. i~ ' relative to the central drive roller at which they '~
stopped (due, for example, to minor drive roller slippage), the , ~Ul . 11y adjusts the rotation of the central drive roller to correct the The tie element attachment portion of the machine is pivotally WO 95/19259 21~1~ 4 ~ PCTlUS95/oo.l79 mounted on the web handling portion thereof, above the inlet and central drive rollers, and rotationally supports a supply roll of an elongated plastic film web , used to form the individual tie elements. During operation of the machine the plastic film web on the tie element supply roll is pulled therefrom and 5 increment~lly advanced, above the inlet and central drive rollers and the folded plastic film bag web, toward the winder m~ c~ As the tie element web approaches the central drive roller a slitter knife i ~l~.y cuts it into the irldividual flexible tie elements which are sequentially moved to positions directly over the central drive roller, and the stopped 1" \z ,~ bag sections thereon, by a vacuum belt.
The inner end of each tie element is then heat welded to a gusseted side edge portion of its associated bag, adjacent the openable end thereof, by means of a first l~;yl~ ~ heating die which also forms a slit tbrough the inner tie element end portion and the underlying gusseted side edge portion of the bag.
The heat weld on the inner end of the tie element e~ctends through all four plastic film layers of the gusseted side edge portion of the associated bag.
Accordingly, very high strength connection is achieved between the flexible tie element and its associated bag.
To maintain each tie element in an e~tended position across an outer side surface of its laterally folded bag, to facilitate packaging of the bags, the outer end of each tie element is releasably restrained against such outer side surface of its laterally folded bag. While this releasable restraint can be ,~ in a variety of manners, it is ~ ,"' ' in a preferred ~W09s/19259 218~ 1A9 ,~""~ .~, 179 of the present invention using a second IC~ JlU~t;ll~ heating die which functions to form by both mPr~ l force and thermal ~I~ f ~ ., a series of "dimples" in each outer tie element end which extend into cu.l~ r formed in the underlying layer of plastic bag film. The interlock 5 between these dimples and bag film ~ keep tne tie elements from flapping about during packaging of their associated bags, but later pem~it each outer tie element end to be easily separated from its associated bag witnout tearing a hole in the bag.
When a bag is ultimately detached from the laterally folded plastic 10 film web, the outer tie dement is simply pulled outwardly fror~ ind detached from the bag. The tie element is then looped around ~he open bag end to form a tightening loop ~h~ ' Finally, the now detached outer tie element end is passed through the slit in tne inner tie element end and pulled to tighten the tie element loop atound the open bag end and tightly close it. The slit length is is preferably somewhat shorter than the tie element width so that as the tie element is passed through the slit the tie element is crumpled and gathered in a manner inhibiting loosening o~ the tie element loop around the bag.
In an l u.. t, a tie strip web is provided with a band of adhesive covered with a release sheet. The tie element web is then severed 20 ~ ly and attached at one end to a side edge of the bag web. The bag is closed by removing the release strip covet, gathering the top of the bag and wrapping the adhesive-coated tie element around the gathered top of the bag onto itself. In one variation, the adhesive is a IGlA~ adhesive without a release cover over the adhesive. The adhesive is designed to have a low tack . .

WO 9S/192S9 2 ~ 9 r~ 179 in contact with the bag web, but a higher tack ~ l ~ r~ wheD
wrapped around the bag in contact with itself. In another variation, the adhesive may be applied in patches on opposite surfaces with or without a release cove}
such that when wrapped around the adhesive on one surface comes in contact 5 with the adhesive on another surface formiDg a bond.
-- The tie element attachment machine of the present invention may be cu..~ / placed "in-line" in an e~isting plastic film bag forming system, and the web handling portion of the macbine may be used to sequentially stop spaced ~ sections of the ~, moving bag web for purposes other than tie elemenl _ ' RRTFF ~E~t'RTPPlON OF TFTF. D~AWINGS
Fig. 1 is a simplified schematic side elevational view of a cu~ ' in-line plastic film bag ~ ~ system in which a tie element attachment machine of the present invention is operably imterposed to attach to each of the individual bag portions of the removing plastic film web a flexible plastic film tie dement which may be wrapped and cimched around the open bag end to tightly close it;
Fig. lA is an eDlarged scale, ~ r~ 1 cross-sectional view, taken along line lA-lA of Fig. 1, through a side edge-gusseted plastic film web being produced by the system;
Fig. 2 is a top plaD view of the moving plastic film web, prior to its entry into the tie element attachment machine, taken along line 2-2 of Fig. l;
Fig. 3 is a top plan view of the moving plastic film web, exiting the tie element attachment machine, taken along line 3-3 of Fig. l;

WO 9~i/192~9 2 1 ~ 1 F~ )b,'' - ~79 Fig. 4 is an enlarged scale, hori~ontally ru~ ul~.l~l cross-sectional view through the moving plastic film web, taken along line 4-4 of Fig

2, illustrating the 1~ manner in which it is laterally folded;
Fig. 4A is a ~;IU~7. !;~liulll view of a non-gusseted alternate 5 ~ of the u.~ .6i..6 right side edge portion of the plastic film web depicted in Fig. 4;
Fig. S is an 1.1A~ of the circled area "S" in Fig. 3;
Fig. 6 is an CIIIAIO ' of the circled area "6" in Fig. S;
Fig. 6A is an enlarged sca'le partial cross-sectiona' view through 10 the film web, and the inner end of a flexible tie element, taken along line 6A-6A
of Fig. 6;
Fig. 7 is an; ' ~ of the circled area ~7" in Fig. S;
Fig. 7A is an enlarged scale partia'l ~u..~ ~L;u.~dl view through a~ outer tie element end, a~ld an underlying bag web portion, taken along line 7A-7A of Fig. 7;
Fig. 8 is a ~..,~liv~ view of a portion of one of the plastic bags and illustrates the manner in which its asso~iated tie element may be used to tightly close the bag;
Fig. 9 is an enlarged sca'e, somewhat simpLified p~ ,~li~ view 20 of the tie element attachment machine;
- Fig. 10 is an en'larged scale pa~lial cross-sectional view through the tie element attachment machine taken a'ong Line 10-lO of Fig. 9;
Figs. I1 and llA are schematic cross-sectional views taken through the tie element attachment machime along ine 11-11 of Fig. 9, and wo 95/19259 2 1 ~ ~ 1 4 ~ r~ .. ,r~ 79 !

sequentially illustrate the alter~at~ng~ ~novement of two slack plastic film webportions disposed wi~in a vacuum bin section of the machine;
Fig. 12 is a schematic control diagram illustrating the feedback Ill;ClUylU~,~aVl control of inlet, outlet and central film web drive roller portions of the tie element attachment machine;
Fig. 13 is an enlarged scale ~ ~Live view of a bag perforation detection system portion of the tie element attachment machine;
Fig. 14 is a schematic ~.u.. ~liul.cl view through the perforation detection system, taken generally along line 1~14 ûf Fig. 13, amd additiûnally illustrates certain control circuitry associated therewith; and Fig. 15 is a front side elevational view of a main control panel portion of the tie element attachment machine;
Fig. 16 is a ~I~LiVt~ view of an improved tie element strip having an adhesive and a removable release coated cover strip over the adhesive shown affixed at one end to the side edge portion of a flattened plastic bag web;
Fig. 1'7 shows the tie element of Fig. 16 wrapped around the gathered top of the plastic bag and par~ally overlapped to close the bag;
Fig. 18 is a ~ view of a variation of the improved adhesive tie element strip having one end affixed to the side edge portion of a 2û flattened plastic bag web and having adhesive patches on opposite side surfaces with removable release patches designed to bnng the adhesive patches together ' when the tie element is wrapped in the manner of Fig. 17;
Fig. 1, is a p~ ~liv~ view of a schematic process for applyimg multiple bands of adhesive to a plastic web, drying the adhesive bands and wo ssllstss 2 1 8 ~ 1 ~ 9 p "~ ~ ,,9 applying protective releasable cover strips;
Fig. 20 is a schematic showing the product of the process of Fig 19 being separated into multiple rolls of adhesively coated tie element web to be used to make tie elements;
S Fig. 21 is a schematic partial cross-sectional view of a modified form of the tie element attachment machme of Fig. 10 illustrating h .~ ly severing individual adhesively coated tie elements from a roll of tie element web shown in Fig. 20;
Fig. 22 is a ~~ iV~ view of another "~1;1; ~ of the 10 improved adhesive iie element strip of Fig. 16 with a ~ 1 adhesive employed without a removable cover strip;
Fig. 23 is a ~l~ iVt~ view of a, ~ ;.,.. of the improved adhesive tie element strip of Fig. 16 in which the releasable cover strip is shortened at the outer end to expose a patch of adhesive.
DETATrrn nF~('RTPrlON
Srh~ ir~1ly illustrated in Fig. 1 is a plætic film bag forming station 20 which, during operation thereof, outputs a laterally folded plastic film web æ (see also Figs. 2 and 3) at a constant linear r gi~ ' ' speed Vl. The bag forming station 20 includes a plastic extrusion die 24 which . '~, extrudes, in an upward direction, a plastic film tube 26. Tube 26 is passed upwardly through a gusset forming structure 27, and then between a pair of flattening rollers 28 and 30, to convert the iube to a flattened tube or "web" 32 (see also Fig. lA) exiting the rollers 28, 30 and having a side edge portion 42 with an inwardly extending gusset 31 extending along its length, the gusset being .

wo 95119259 2 1 ~ ~ 1 4 9 - P~ c- ~79 ~

defined by four layers of plastic fiiqn After its exit from the rollers 28 and 30, the web 32 is sequentially passed over the rollers 34 and 36 and fed through a heat sealing, folding and perforation apparatus 38.
The ~ y depicted apparatus 38, as its name implies, S sequentially perforrns three operations on the web 32 traversing the apparatus.
First, it forms on the web a l~ c;~ y spaced series of laterally extending heat seal weld lines 40, each of which extends between the side edge 42 of the web 32 and its opposite side edge 44 (see Fig. 4).
Next, as cross-sectionally illustrated in Fig. 4, the web 32 is laterally folded along the l~ncjtn~iir~lly extending fold lines 46 and 48, the fold line 46 being laterally aligned with the side edge 44, and the fold line 48 being laterally inset from the side edge 42. As best seen in Fig. 4, the lateral inset of the fold line 48 causes a side edge portion 42a (containing the gusset 31) to extend laterally beyond the balance of the laterally folded, flattened film tubewhich ultimately defines the laterally folded plastic film web 22. The number of folds in the folded web æ are, of course, merely IC, ~ - a greater or lesser number of folds could be forrned.
After the web 32 has been heat sealed along lines 40, and laterally folded as just described to create the folded web æ, the apparatus 38 operates to form on the folded web 22 a l~ih~ y spaced series of laterally extending perforation lines 50 which extend completely across and through the laterally folded, web æ. As illustrated in Fig. 2, each of the perforation lines 50 is positioned leftwardly adjacent one of the heat seal lines 40. Accordingly, the heat seal lines 40 and the perforation lines 50 form on the laterally folded plastic ~ WO 95119259 2 1~ 114 9 F~ 179 film web 22 exiting tbe apparatus 38 a 1, v ' ' series of laterally folded individual plastic film bags B which may ultimately be separated from one another by tearing the film web 22 along the perforation lines 50. When this is done, each individual bag, in the usual manner, has an openable end extending S along one of the ~ rulaLiu,~ lines 50, and a closed, opposite end extending along one of the heat seal lines 40.
Referring again to Fig. 1, the laterally folded plastic film web 22 exiting the apparatus portion 38 of the bag forming station 20 is forcibly captured in a ~U~ iUllod winder 52, spaced apart in a leftward direction from the bag forming station apparatus 38, at a constant linear speed V2 equal to thelinear output velocity Vl of the film web 22 from the bag forming station 20.
To provide tension control therefor, the folded web æ is passed beneath a stationary roller 53, and over a pivotally mounted dancer roller 54 prior to beimg drawn into the winder 52 wherein it is wound upon a suitable storage roll (not il- 1) Operably interposed between the bag forming station apparatus 38 and the winder ' 52 is a tie element attachment machine 'v;0 which, as ly described, is utilized to secure to each of the imdividual bags B, adjacent its openable end, a plastic film closure tie element 62 as illustrated in 2û Figs. 3 and 5 which are top plan views of the laterally folded plastic film web æ as it exits the machine 60. Macbine v0 basically comprises a web handling portion 60a, and a closure tie element attachment portion v0b which is mounted atop the web handling portion 60a and is pivotable relative thereto between a lowered operating position (shown in solid lines in Fig. 1) and a raised access :
woss/ls2~s ~18~ ~49 r~ a~ 7s 16 ~.
position (shown in phantom in Fig 1). A schematic, ~ ~I; ri ~ of tie element attachment machine 60 shown in Fig. 21 is employed to apply adhesive tie element strips from a tie element web as will be described later.
As will be seen, the web handling portion 60a operates to engage S and leftwardly drive a 1 ~gi~ y central portion of the folded web 22, positioned between the apparatus 38 and the winder ~I~ r~l 52, and to sequentially and mn~nt~rily stop each of the individual bags B and stationarily position a ~ section thereof for attachment thereto of the bag's associated closure tie element 62. I~ Iy~ this ;--t . ~.. '1. ..1 stoppage of each of the individual bags moving from the apparatus 38 to the winder l~ ;e~
52 is effected without ;~ .;dWy altering the web output and intake linear velocities Vl and V2 and without imposing upon the I gi~ moving web 22 ~ high l~ g ' ' tension forces which might otherwise tear the web at one of its perforation lines 50.
The tie element attachment portion 60b of the machine 60 is Iy ~ ' ' with the web handling portion 60a, and is operative to form the individual tie elements 62, from a plastic film supply roll 64, and attach the formed tie elements to the sequentially stopped I~ ' ' sections of the individual bags B.
Before describing in detail the structure and operation of the tie element attachment machine 60, certain features of the tie elements 62 will be briefly described wi~h reference to Figs. 1 and 5-8. The .q..~
illustrated tie element supply roll 64 is formed from a lateral half of an elongated, flattened plastic film tube which has been cut along its central 21~ 9 wogS/19259 - - - r~ 79 ih~ axis with a heated slitting knife or wire. The lateral flahened web half used to form the tie element supply roll 64 thus defines an elongated, dual layer plastic film web 68 (Fig. 10) having a folded side edge 70 (Fig. 9), and an opposite, heat sealed edge 72 which was previously formed by the heated slitting S knife or wire. It will be ~.y~ ' that, depending upon how the tie element web 68 was initially formed, both of the edges 70, 72 could be heat sealed edges.
As will be seen, the web 68 is drawn through the tie element attachment portion 60b of the machine 60 and is laterally cut into elongated ships that define the tie elements 62 which are secured to the individual bags B. Other improved forms of elongated adhesively coated tie element shiips and methods of rnaking and applying them are shown in Figs. 16-23. They will be described later.
As best seen in Figs. 5-7, each of the tie elements 62 has an inner end portion 62a which includes a portion of the folded side edge 70 of the tie element web 68 and overlies the u.. ' _ _ side edge portion 42a of the laterally folded plastic film web 22. The tie element inner end portion 62a is firmly secured to the web side edge portion 42a by means of a circular heat web 74. As best illustrated in Fig. 6A, the held weld 74 extends through all four plastic film layers of the gusseted side edge portion 42a of the folded web 22.
A l ~ extending slit 76 is formed through the tie element 20 end portion 62a, and the underlying web side edge portion 42a, and is positioned within the circular heat weld 74. From its secured inner end portion 62a, the tie element 62 extends 1. . ~ y across the upper side surface of the folded web 22, with the tie element 62 being parallel to and adjacent the ~r~ line 50 that defines the openable end of the individual bag with which the particular tie WO 9!i/192~i9 2 1 8 1 14 ~ r~ 1/U~,5.'~ ~ ~79 dement is associated.
The anchoring of the ,in~ner end of each tie element 62 (by the circular heat weld line 74) to all four layers of the gusseted side edge portion 42a of the folded web 22 provides a very strong illt~l~ between e~ch tie S element and its associated bag B. However, if desired, the side edge gusset 31 could be omitted (by omission of the gusset forming structure 27 shown in Fig.
1) so that the u.. ' , ~ side edge portion of the folded web 22 would have only two plastic film layers (see the alternate side edge portion 42b in Fig 4A).
The inner end of each tie element 62 would then be heat welded (along the ~ circular weld line 74)1 to the two film layers of the modified side edge portion 42b.
Each of the tie elements 62 also has an outer end portion 62b, containing a portion of the heat sealed side edge 72 of the tie element web 68, which is positioned laterally inwardly of the web fold 46. The heat sealed joint at the outer end of the tie element 62 is not I 1~, strong due to the fact that it was formed by a he~ted slitting knife or wire. A' " ~'~" a pair of laterally extending heat weld lines 78 are formed on the tie element 62 adjacent its outer end, in a manner 1 'y described, to more firmly intersecure the two plastic film layers of ~he tie element in that region.
To releasably restrain the tie element 62 in place across the top side of the laterally Eolded plastic film web 22, so that the web 22 and the attached tie elements 62 may be smoothly drawn into the winder ' 52, five small dimples 80 (see Figs. 7 and 7A) are formed in the outer tie element end 62b and are received in C.~. IL ~ .--- 80a in the plastic web WO 95119259 21~ 9 PCTIUS95/OW79 film layer beneath the tie element. As ~U~S.~U~ y described, a heated die is used to form these dimples and d~l~ iullS which are formed by a ~
of m~h^~ forceand ~h ~ ` distortion without~ ~;d,ly heat welding the tie element end 62b to its associated bag. Accordingly, tbe tie element end 62b can later be pulled apart from the bag without tearing the bag. To use a tieelement 62 to tie offand close the open end of its associated bag B, the outer end of the tie element 62 is simply pulled apart from the bag film layer to which itis releasably restrained by the ' ' ~ dimples 80 and .1~ 80a.
After this is done, the tie element 62 remains very firmly anchored to its associated bag B by the circular heat weld 74 at the inner tie element end.
As illustrated in Fig. 8, tbe tie element 62 may then be used to tightly close and se 1 the open end 82 of its associated bag B by simply wrapping the tie element 62 around the open bag end, passing the outer tie element end portion 62b through the slit 76 to form a loop 84 around the open bag end, and then firmly pulling on the tie element to cinch the loop around the bag. The length of the slit 76 is preferably made somewhat shorter than the width of the tie element 62 which tends to crumple and gather the tie element as indicated at62c, at its juncture with the slit, thereby ' 'ly inhibiting loosening of the bag-closing tie element loop 84.
The illustrated closure tie element 62 is merely -r ' ' vt~ of a wide variety of tie element structures which could be attached to the individual bag portions of the laterally folded plastic film web 22. A variety of alternateclosure tie element c-- r~ are illustrated and described in U.S.
application Serial No. 117,209 which has be~n ill~.Ul~ ' ' herein by reference.

WO 95/19259 2 ~ 8 ~ 179 ~

Adhesively coated forms of tie element web and strips are disclosed in Figs. 16-23.
Referring now to Figs. ~ and 9, the tie element attachment machine 60 includes a generally l~ ~ ' support frame structure 86 which is S floor ! r ~1~ on îour vertically adjustable support feet 88 positioned at the corners of the support frame structure. The web handling portion 60a of the machine 60 is carried by a front side portion of the frame structure 86 and includes three drive roller members - an imlet drive roller 90, a central drive roller 92, and an outlet drive roller 94. As illustrated, the rollers 90, 92 and 94 extend horizontally, are laterally spaced apart, and are in essentially the samehorizontal plane.
The three drive rollers I ~ , e~ctend in a front-to-rear direction relative to the support frame structure 86, and are pivotally supported at their opposite ends on support frame portions 96 and 98. Roller 92 is spaced leftwardly from roller 90, and roller 94 is spaced leftwardly from roller 92. AsC, h. .".~;...lly depicted in Fig. 12, the roller 90 is driven in a ~
direction by a motor 100, roller 92 is driven in a, ' ' ;,~ direction by a stepper motor 102, and roller 94 is driven in a . .,I~L~;,~ direction by a motor 104.
Supported by a front side portion of tne support frame structure ~6 directly beneath tlle rollers 90, 92 and 94 are a side by-side pair of metal vacuum bins 106 and 108 (cross-sectionally illustrated in Fig. 11), bin 108 being positioned ' '~, to the left of bin 106. The vacuum bins 106, 108 have generally ~ open top ends 110 and 112, bottom walls 21~ 9 r~ ,s~~17s J ~ 21 114 and 116, a common central side wall 118, outer right and left side waUs 120 and 122, rear walls 124 and 126, and front side walls 128 and 130. As illustrated in Fig. 11, roller 90 is positioned above and tangent to the bin wall 120, the roller 92 is positioned above the top end of the central bin wall 118 and 5 is tangent to its opposite sides, and the roller 94 is positioned above and tangent to the bin wall 122.
For purposes later described, a vacuum pump 132 (Fig. 9) is supported by the frame structure 86 generally behind tbe left vacuum bin 108 and has an inlet 134. The inner ends of a pair of fle~;ible vacuum hoses 136 and 138 are connected to the inlet 134, and the outer ends of the hoses 136, 138 are ly connected to the bottom vacuum bin walls 114, 116 and with the interiors of the bins 106, 108. The interiors of the vacuum bins 106, 108 ~ with one anotner via a transfer passage 140 formed tbrough a lower end portion of the common central bin waU 118 and r " ' ,, to generally equalize the vacwms drawn in the t vo bins.
Also for purposes later desaibed, a verticaUy spaced series of five beam i ~ units 142, 144, 146, 148 and 150 are mounted on the right bin side wall 120 and are adapted to leftwardly transmit 1 beams 152 across the interior of vacuum bin 106 for receipt by a vertically 20 spaced series of beam receiving members 142a- lSOa mounted on the central bin wall 118. In a similar fashion, a vertically spaced series of L ' ' beam 154, 156, 158, 160 and 162 are mounted on the left bin side wall 122 and are operative to l;6~l~wa~dly transmit L ' ' ' ' - beams 164 across the interior of the left vacuum bin 108 for receipt by a vertically spaced series of .

wogsllg~9 2 ~11 4 3 PCT/US9~/00179 ~

beam receiving units 154a-162a.
Referring now to Figs. 9 and 11, the web handling portion 60a of ~he tie element attachment machine 60 also includeS i`- pair of pinch rollers 166 amd 168 which are rotationally carried at their outer ends by arm members 170, '172. The inner ends 3f the arm members 170, 172 are pivotally carried by a pair of upright support plate st~uctures 174 and 176 which project upwardly fromleft end sections of the support frame portions 96, 98. As illustrated, the arm members 170, 172 are J~ udly pivotable to ~ ly position the pinch rollers 166, 168 agaillst upper portions of the outlet drive roller 94 and the ,central drive roller 92. A third pinch roller 178 is similarly carried on a pair of arms 1~0 pivotally secured at their inner ends to a pair of upright support bracket structures 182, 184 positioned along right end sections of the support frame portions 96, 98. The arms 180 are ~....~udly pivotable to position the pinch roller 180 against an upper portion of the inlet drive roller 90.
, Referring now to Figs. 1 and 11, the laterally folded plastic film 'web 22 exiting the bag forming station apparatus 38 is e~tended through a CUII~L '' 1 web gui~e apparatus 186, secured to a right end portion of the support frame structure 86, which functions to: 'Iy maintain proper lateral alignment of ~he web during operation of the overall system. Upon leftwardly exiting the web guide apparatus 186, the web 22 ~ passes beneath a guide roller 188, between the drive amd pinch roller sets 90 and 180, 92 amd 168, and 94 a~d 166, beneath a guide roller 190, beneath the stationary rolle} 53, and over the pivotally mounted dancer roller 54 and upwardly into thewinder ' 52. Utilizing the ~ . 1y described control system 192 ~ wogS/19259 23 21~ P~ c ,,9 - (Fig. 12), start-up of the web handling portion 60a of the machine 60 is effected as follows.
The web 22 is loaded into the tie element attachment machine 60 by initially passing the web under roller 188, resting the web atop the three drive S rollers 90, 92 and 94, amd passing the web beneath roller 190 and o~~ ly connecting it to the winder 52. A switch 331 on a main control panel 332 (Fig.
15) is then moved to its "LINE" position which, via a llli~ lu~Jlc~la~l 198 (Fig.
12), initiates the operation of rollers 90 and 94 at rotational speeds wll. r to the ]ine~r web velocity Vl.
When it is desired to attach tie elements to tne web æ, an operator moves the switch 331 from its "LINE" position to its "RUN" position. This signals the Illi~.lUIJIU~aa~J~ 198 to energize the vacuum pump 132 (Fig. 9) and slow the rotation ûf roller 94 via an output signal 208 h ' to its speed wntroller 210. The slowing of roller 94 causes the web æ to be pulled 15 du~Jly into the vacuum bin 106. In a manner ' , '.~, described, when web æ du....w~.-lly reaches a I " ' level witbin bin 106, the UIJlU~aaOl 198 transmits am output signal 200 to speed wntroller 202 (Fig.
12) to rotationally "step" the roller 92 at a rotational velocity greater than the linear velocity V1, permittmg the web æ to be vacuum-drawn ~' ..A.w~udly into bin 108 into a looped . S, 204 until, in a maumer ' ~
described, the ,UllC I ~ ~ web loop 194 in bin lOo is shortened and the loops 194 and 204 are in their relative length ,~ , illust~ated in Fig. 11. In such length tbe loop 204 is ~ , longer than loop 194.
After this initial length ' between the web loops 194, .. .. . . . .. . .

2 1 ~
WO gS/19259 ! ~ r~ c 204 is achieved, the ~ lul,l~ol 198 signals speed controller 210 to operate roller 94 at a rotational speed equal to that of roller 90 to maintain the web loops in this initial length ,,~ Upon attainment of this condition, the switch 331 is moved to its "RUN" position which, via the ~ u~ ol 198, lowers the tie element porlion 60b of machine 60 to be lowered into itS operative position.
During the start-up, with the folded plastic film web 22 being outputted from the sealing, folding and perforating apparatus 38, the motor 100 rotationally drives the inlet roller 90 at a constant torque and at a ~;uullt~ wiac, variable rotational speed ~ to the linear web output speed V1 so that the wcb tal~up speed of the roller 90 is equal to the linear web output speed from the apparatus 38. The above~escribed slowing of roller 94 for[ns a slack portion of the web 22 between the rotating drive roller 90 and the stationary central drive roller 92. The operation of the vacuum pump 132 (Fig. 9) creates a yielding vacuum force within the vacuum bin 106 which draws this slaclc web portion du.. dly into bin 106 and gently holds it in the illustrated, du.... ~diy loopecd ~ I,,," 194 (Fig. 11). As the roller 90 continues to rotate, the vertical length of the web loop 194 ~-----d~llr increases.
The increasing length of the web loop 194 is '!1 monitored by the l ' : ' beam receivers 142a-lSOa supported on the central bin wall 118. It can be seen in Fig. 11 that as the web loop 194 e~tends further du .. I.~udly within the bin 106 it sequentially blocks lu ....w~udly successive ones of the ~ t~ l.. ~ beams 152. When the lower end of the loop web 194 Owoss/ls2ss 25 218~14~ r~ m c l79 duwv~lw~ly reaches a ~ ' ver~ical level within the bin 106, a vc~ signal 196 (Fig. 12) is; ' from the receivers 142a-150a to a l..k,l~J~JlU~ VI 19g, the signal 196 indicating that the vertical length of the web loop 194 has reached its desired magnitude.
Upon re~eiving the signal 196, indicating that the web loop 194 has reached its desired initial length within the bin 106, the II.i~,lU~JIU~i~lVI 198 ~u~ ly transmits an output signal 200 to the speed controller 202 which in turn, operates the motor 102 to step the central drive roller 92 at a faster speed than the inlet roller 90, thereby initiating the formation of web loop 204. The stepped rotation of the central drive roller 92 incre~ses the length of the resulting slack web portion between the rollers 92, 94, the vacuum force within the left bin 108 exerting a yielding downward force on this second slack web portion to convert it to the secorld du .. Ilwal-lly extending web loop 204. When the bottom end of the web loop 204 is properly positioned within bin 108 (see Fig. 11), the 15 ~ receivers transmit through the , U~,vl 198 a ~
signal 206 indicative of the fact that the left web loop 204 has now reached its desired initial vertical length.
Mi. .,~..1,.. -`-.. 198 then 1~ -r ~,ly transmits am output signal 208 to a speed controvller 210 which operates the motor 104 to initiate a change 20 in rotation of the outlet drive roller. The roller 94 is driven at a rotational speed identical to that of the inlet drive roller 90 via the operation of a magnetic speed ænsor 212 that monitors the rotational speed of a smaU gear member 214 secured to the front end of the inlet drive roller 90 for rotational therewith. Speed sensor 212 ~vll.;~ly transmits to the U~JlUC~Vl 198 a rotational speed-indicative 21~ 9 WO 9~/192!i9 - ` P~ S~ 79 output signal 216 which, in a feed~ack manner, is operative to adjust the outputsignal 208 to the speed controller 210, to thereby equalize the rotational speeds-of the inlet and outlet ~rive rollers 90, 94. With the three drive rollers 90, 92 and 94 being operated at essentially constant speeds, the heights of the web loops 194 and 204 are mainained in their length ,~l :;""~ , illustrated in Fig. 11 during the start-up phase of machine operation.
The IllI~,lU~lU~i.lJI 198, and the speed controllers 202 and 210, are c~ , positioned within a rear side portion of the support frame structure 86 (Fig. 9) along with various other cantrol, ll generally indicated by the refererlce numeral 218. After the previously described start-upprocedure has been ~".~ ,.~ the web handling position 60a of the machine 60 is converted to its na,rmal operating mode by moving switch 331 to its "RUN"
position. In this operat~ng mode, the inlet and outlet drive rollers 90, 94 are still rotated at constant and essentially identical speeds, but the central drive roller is lS sequentially started and stopped to ~ and stationarily position L,ir " I sections of each individual bag B, adjacent its perforation line 50 that defines its openable ~nd, to ready such l~ gjh~ l bag sections for the attachment thereto of the tie elements 62, or the tie elements shown in Figs. 16-23, in a manner ' , '~1 described.
Quite '~" this sequential stoppage of each individual bag B at the central drive roller 92 is P " ' ' without ~ ly altering the const~nt output and intake velacities V1 and V2 of the l".,~ =lly moving folded plastic film web 22 as it approaches arld e~its the tie element attachment machine 60. Additionally, as will be seen, due to the unique formation of the WO 95/19259 2 1 8 1 1 ~ 9 P~ 179 web loops 194 and 204 such individual bag stoppage is effectcd without imposing upon the web 22 ~ 1 tension forces which might otherwise te~r the ;eb at one of its ~rUl~liOI~ lines 50. The unique a l-;~ ~, of these two very desirable results will now be described in, with Figs. 11 and S llA.
In Fig. llA, the central drive roller 92 has been stopped, during the continuing rotation of the inlet and outlet drive rollers 90 and 94, to thereby ~r~l~torjly hold the bag portion Bl thereon with the openable end perforation line SOb of the bag Bl being ~' ~w~ldly adjacent the central drive roller 92, and 10 the opposite end pelrul~iull line SOa of the bag Bl being positioned upon the web loop 204 being vacuum-drawn du.. ,cu-lly into the bin 108 through its open upper end 112. The l.~,n~ l section of the stopped bag B1 positioned atop the now stationary central drive roller 92 . ' to the I ~ ' ' section of such bag to which its closure tie element, such as element 62 will be affi~ced.
During its y stoppage, the central drive roller 92 does not, of course, continue to drive a left side portion of the right web loop 194 into the left vacuum bin 108. However, the continued rotation of the inlet and outlet drive rollers 90, 94 continues to feed the web 22 into the right vacuum bin 106, and withdraw the web 22 from the left vacuum bin 108. This functions to lengthen the web loop 194, while shortening the web loop 204, as ~ ly indicated by the arrows æû and 2æ in Fig. llA. The left web loop 204 is shortened against the d~ woldly directed vacuum force imposed thereon by the vacuum pump 132. Accordingly, the tension force exertcd on the web loop 204 by the ,. '~, rotating outlet drive roller 94 in ' to tear any of wo ss/l s2ss 2 1 8 1 1 4 9 F ~ ~ . , ,9 the web perforation lines disposed wi~}un th~ lefl vacuum bin 108 - all the outlet drive roller 94 does during this period in which the central drive roller 92 is '~, stopped, is take up the slack in the left web loop 204.
After its tie element 62 is secured to the Iy stopped bag Bl, as monitored by an ~ .ul sensor æ4 (Fig. 12), the sensor 224 transmits an-output sig~al 226 to the u~lu~Daul 198 indicating that the tie dement has been attached. The roller 92 is not c ~ i to rotate until photocell 150 is covered by web loop 194, at which time the output signal 196 is i ' to Illi~ lUU,.~aVl 198. When the signal 196 is received by the 0 ~llil,lUylVC.,.. aVl, the u~lu~ , adjusts its output signal 200 to the speed controller 202 to operate the stepper motor 102 in a manner such that the central drive roller 92 is . ~ started and rotationally P- ' ' to . ' ' Y;~ rotational speed higher than the speeds of the inlet and outlet drive rollers 90 and 94, maintained at this elevated speed for a 1~ time period, ~ ' I, and stopped.
The result of this speed control cycle of the central drive roller 92 is that at the moment of its stoppage subsequent to the attachment of the tie dement to the bag Bl, the right web loop 194 has been rc 1~ ~ and the left web loop 204 ., ' ~..~, to their original lengths as depicted in Fig. 11.
20 Additionally, the next bag B2 has been stopped at the central drive roller 92, with the openable and perforation line 50c of bag B2 positioned ~' woldly adjacent the roller 92, and the opposite perfûration line 50b being nûw positioned within the left vacuum bin 108.
After Ws stoppage of the central drive roller 92, which readies the _ . _ , . . . . . . _ _ _ 21811~
w0 sslls2ss ~ 79 bag B2 for the attachment of its tie element thereto, the web loops 194, 204 again begin to l~ iV~y lengthen and shorten as illustrated in Fig. llA. The elevated speed level of the central drive roller 92, which shortens the web loop - 194, does not implose, ' ~ , high 1 ~i~ " ' tension force on the loop 194, 5 since the roller 92 merely takes the slack out of the previously lengthened loop 194 against the yielding, du.... ~ly directed vacuum force on such loop within the right vacuum bin 106.
It can thus be seen that the web handling apparatus of the present invention, by means of the formation and length control of the two web loops 194 and 204, permits the sequential stoppage of each individual bag without u.. ~ the web æ or at",l~;~l~ altering the linear output and intake speeds V1 and V2 of the web.
It will be ~rP ' that the U~JIU~i~JI 198 may be easily to operate the speed controller 202 such that, during each period in which the drive roller 92 is rotated, the stepper motor 102 inputs the proper number of rotational "steps" to the centlal drive roller 92. The roller 92 sequentiaUy advances the web a distance equal to the length of the individual bags being produced, and that the time period between stoppages of the roller 92 is ~ ' ' to essentially equalize the lengths of the web loops 194, 204 each 20 time the central drive roller is stopped.
In addition to precisely controUing each web ~lv length of the roller 92, it is also important to insure that as each individual bag is stop~ed at the central drive roller, the openable end perforation line of such bag is properly positioned relative to the stopped roller so that each attached tie W095/19259 21811~9 F.l/O..,_. ~79 element is properly posi~oned on its associated bag. In the present invention, this is achieved by the use of a specially designed perforation detection system230 which is illustrated in Figs. 11, 1 lA, 13 and 'I4.
The perforation detection isystem 230 includes a high voltage electrode member encased in an insulation tube 232 which is mounted on &e outer end 234 of an L-shaped support arm 236 which extends rearwardly through an opening 238 formed in the rear side wall 124 of the right vacuum bin 106 adjacent its upper end and the upper end of the central bin wall 118. The inner end 240 of the support arm 236 is positioned behind the bin wall 124 and is secured to a pivot pin member 242 which permits the support arm 236 to pivot about a horizontal axis, as indicated by the double-ended arrow 244 in Fig. 13, between an operating position shown in Fig. 13 and a stowage position in which the electrode 232 and tlle outer end 234 of the support arm 236 are rearwardly pivoted through the bin wall opening 238 and are withdrawn from the vacuum bin 106.
With the support arm 236 forwardly pivoted to its operating position, the portion of the support arm e~tending forwardly through the bin waUopening 238 rests upon and is supported by a horizontally extending tab porlion 246 of the rear side bin wall 124, and the left or discharge end 232a of the electrode 232 is positioned slightly li~ Wald;,~' of the central bin wall 118.
Directly to the left of the inner electrode end 232a is a circular opening 248 formed in the central bin wall 118. As cross-sectionally illustratedin Fig. 14, a cylindrical insulator member 250 has a boss portion 252 positionedwithin the bin waU opening 248, and a grounded cylindrical Inetal conductor W095/19259 31 21811~9 F~ 179 member 254 extends coa~ially through the insulator member 250, the e~posed right end of the conductor member 254 facing the inner end 232a of the electrode 232.
As illustrated in Figs. 11 and 14, a left side por~ion of the right web loop 194 is routed upwardly between the electrode 232 and the insulator 250 onto the central drive roller 92. Accordingly, during operation of the tie element attachment machine 60 the web perforation lines 50 are sequentially passed between the electrode 232 and the conductor 254. The electrode 232 is connected via a lead 256 to a high voltage power supply device 258 which functions to create a high voltage potential across the gap between the electrode 232 and the conductor 254 is normally prevented by the high dielectric constant of the plastic film material of the web 22 positioned in such gap.
However, each time a perforation line passes through this gap, an electrical discharge occurs from the electrode 232, through the r r... ~ ;~ ", line, to the conductor 254, and then through the conductor to ground. This creates a current flow from the electrode to ground, which is sensed by a current sensor 260 that ~ u.~ ly transmits a ~ output signal 262 to the llfi.,lUIJlU~i~Ul 198 (see Fig. 12). In this manner, a precise ~ of the position of the openable end perforation line of each of the individual bags is 20 achieved so that when each individual bag is stopped at the central drive roller 92, the ~ " ' section of each individual bag to which its tie element is to be attached is also precisely positioned.
Should the control system 192 detect a deviation in the desired position of the openable end perforation line 50 when a particular bag is stopped 21~1149 WO 9~/192~9 , . ~ C ~ ~79 at the central drive roller (such deYiation being caused for e~ample, by roller slippage) the IIUClvlJIuCCoovi 198: 'Iy~f~ctions to adjust the signal 200 being transmitted to the speed controller 202 to 'y increase or decrease the, ~,lo~w;O~, rotational steps of tbe roller 92 to readjust the stopped bag S position on the central drive roller 92, and , ~ , adjust the signal 200 to increase or decrease the total number of rotational "steps" imparted to the central drive roller 92 during one start-stop rotational cycle thereof, thereby properly readjusting tbe ll nL ' I orientation of each indiYidual bag as it is stopped at the central d1ive roller 92.
Normally, the rotational speeds of the inlet and outlet dlive rollers 90, 94 are the same. ~Iowever, at certain web velocities and bag lengths, the web loop 204 in the vacuum bin 108 may become too long or too short during the tie element attachment process. When the web 204 is too long (such as, for example, the photocells 160 or 162 are coYered by the loop 204), the II~;Clu~luu~vl iS signaled and l~-r ._1~ causes the controller 210 to increase the rotational speed of roller 94. In a similar fashion, when web loop 204 becomes too short (such as, for e~ample, when photocells 156 and 158 are uncoYered), an err ~ signal is sent to the UIJlU~oUl which, in turn, temporarily slows the rotational speed of roller 94.
The pivo[al mounting of the electrode 232 on the L,shaped support arm 236 funceions to prevent ehe web 22 from being tom at one of its perforationlines 50 in the event that the right web loop 194 is shoreened to an extent that its lower end contacts the ~uter end 234 of the support arm 236. In the evene that this occurs, the web merely pivots the support arm 236 rearwardly to its stowed W09S/192S9 r~ 79 position in which it is disposed entirely behind the bin wall 124 by movement through the bin wall opening 238 as previously described.
The control system 192 described in c ; with Fig. 12 is, of course, adjustable to . , - for different bag lengths being driven through 5 the web handling portion 60a of the tie element attachment machine 60, the bag length being the distance between se~uentially adjacent pair of ~lruld~.l ]ines 50. The web handling portion 60a may also be easily adjusted to for folded webs of different widths. This width adjustment is achieved in the present invention by providing means for selectively varying the effective front-to-rear widths of the vacuum bins 106 and 108. Such bin width adjustment is obtained by mounting the front bin walls 128, 130 for selective front and rear movement relative to the balance of the bins.
Referring now to Fig. 9, upper and lower support members 264 amd 266 are suitably secured between the central bin wall 118 and the outer side walls 120, 122 of the vacuum bins. Internally threaded nut members 268, 270 are captively retained on the upper and lower support members 264, 266 for rotation relative thereto and i' ' l~, receive elongated e~cternally threaded rod members 272, 274 welded at their inner ends to the movable front bin walls 128, 130. Along their opposite vertical sides, the front bin walls 128, 130 are 20 provided with resilient seal members 276 which slidingly engage the opposite left and right side waUs of each bin.
Sprocket members 278, 280 are ~ ~ secured to the upper and lower nut members 268 and 270, and are drivingly - ' by suitable chains 282. The upper nut members 268 have secured thereto suitable W095/19259 218~149 E~,l/U' ~'C-~79 adjustment knobs 284 which may be rotated to effect forvard or rearward movement of their associated front bin walls. For exampIe, as viewed in Fig.
9, clockwise rotation of one of the adiustmént knobs 284 effects forward movement of its associatc-d front bin waU, while . ;~ rotation of the S adjustment knob causes rearward movement of tne front bin wall. In this manner, front-to-rear width adjustment of the t vo vacuum bins may be obtained so that the front-to-rear width of the bins is just slightly larger than the width of the folded plastic film web being used in a particular bag run. This width adjustment capability assures that the downward vacuum force applied to the web loops in each of the bins is efficiently applied to such loops.
The web llandling apparatus oOa just described is ~ ,ul~ly well suited to its illustrated use in handling the folded plastic film web æ used in the in-line production of plastic bags in which it is necessary to 1~, stop lly spaced apart sections of the . ~.~, moving web to secure flexible tie elements to the stopped web sections. EIowever, it will be readily ~ ' that the unique structure and cperation of the weo handling apparatus would also be quite useful for the ~ . r.... -- ~ of operations other than tie element attachment - for example, in printing, attachment of au~iliary of other types, arld the like.
Tu}ning now to Figs. 9, 10 and 21, tne tie element attachment portion oOb of the machine oO will be described in detail. Common portions of the schematic .... ~1.1;. -I l..., of Fig. 21 will be indicated by the use of prime marks over the same numerical items. Some parts of Fig. 10 have obviously been dropped from Fig. 21 as not necessary to the adhesive coated tie element strip i WO 95/19259 21811 ~ 9 F~.IIIJ., '~ 179 shown in Figs. 16, 18, 22 and 23 and/or are CUII~..JUIIal. Most notably the first heat sealing device 306, support plate 296 and associated rollers are not necessarily ne~ded. The support spindle 66, 66' of the tie element supply roll 64, 641 is rotationally supported on the upper ends of a pair of upright supportbars 286 extending upwardly from the support brackets 182, 184 positioned at a right front corner portion of the support frame structure 86 as previously described. Extending leftwardly from the support brackets 182, 184 are a spaced pair of support arm structures 288. The support arm structures 288 are secured to the brackets 182, 184 and are pivotally carried by a support rod structure 290 so that the tie element roll 64, 641 the support bars 286, and the support arm structures 288 may be pivoted between the solid line, lowered operating positionof the tie element attachment portion 60b and its dotted line raised access position ~ly depicted in Fig. 1.
As best seen in Figs. 10, 21, the tie element web 68, 681 extends d~ udly from the supply roll 64 and is passed under a dancer roller 291, 2911 which is pivotaUy carried on support arms 292 secured at their irmer ends to the brackets 182 and 814. The web 68, 681 then passes upwardly around an upper guide roller 292, 2921 beneath a lower guide roller 294, 2941 and across a support plate member 296 extending between and supported by the support arm structures 288. As it leftwardly exits the support plate member 296, the web 68,681 passes over a guide roller 298 and wraps around a drive roller 300 which advances the web 68, 681 a l ' ' length into a verticaUy opposed pair of drive rollers 302, 3021, 304, 3041 that operate to pull each sheared-off tie element 62, 621 from a shearing knife 310. (Drive rollers omitted in Fig. 21) 21811~9 WO 9~i/19259 ~ 79 As the web 68"68' iS~d~awn leftwardly along the upper side ;; .. ~ .
surface of the support plate member 296, a Yeriically ~ u~Lill~ heating die 306, ca~ried by the left support arm structure 288 and positioned above the support plate member 296, may form the weld lines 78 (Flg. n on 1....~ ly spaced apart sections of the leftwardly moving tie element web 62. As the web 68, with the weld lines 78 thereon or the web 68' leftwardly exits the guide roller 300, it passes between the base alid lv~ ,lu~Li.~ knife portions 308, 308' and 310, 310' of a vertically lc~ilJIu~L..~, slitiing hiife m~~ r~ 312, 312'.
Operation of the vertic~lly lC~ lU~,4Lllg knife 310, 310~ ,ly separates the individual tie elements 62, 62' from the leftwardly moving web 68, 681. As each individual tie element 62, 621 exits the siitting 312, 3121 it is drivingly engaged by the drive rollers 302, 302', 304, 3041 and moved leftwardly between a pinch roller 314, 314' and the bottom side of a rotationally driven vacuum belt 316, 316' positioned over the ceni~al drive roller 92, 92'.
As illustrated in Fig. 10, clockwise rotation of the vacuum belt leftwardly transports the individual tie elements 62, 621 and positions the leftmost tie element directly above the central drive roller 92, 92' and the 1-- 6~
section of the folded piastic film web æ ~ stopped thereon. With the leftmost tie element 62, 62' stopped in t}iis position, its inner end portion 62a, 62al extends forwardly beyond the front side edge of the vacuum belt and is positioned over the U.~ side edge portion 42a of the folded web 22 (Fig.
4j, and iis outer end portion 62b, 62b' (which e~tends outwardly beyond the rear side edge of the vacuum belt) is positioned as illustrated in Fig. 5.
To attacl1 the leftmost tie element 62, 62~ to ihe particular W095/19259 21811A9 r~ J.,J~ 179 individual bag stopped at the central drive roUer 92, a pair of lec;~lu~aLillg heating dies 318 and 320, 320' are mounted at the left ends of the support arm-structures 288 and are I~D~IiV~1Y positioned over the outer and inner end portions of tne leftmost tie element depicted in Fig. 10 which lateraUy e~tend 5 beyond the opposite side edges of the vacuum belt. The heating die 318 may be utilized to form the small circular dimples 80 (Fig. 7) on the outer end of the leftmost tie element 62, and the heating die 320, 320' is used to form the circular weld line 74, or an oval weld line 74' and if desired the slit 76, on the inner end portion of the tie element.
It will be a~ ' that the rate of a~ . of tne individual tie elements formed from the leftwardly advancing web 68, 68' in the tie element attachment portion 60b of the machine 60 is a~lul '~, and ~
sequenced relative to the sequence and speed of folded web ~lv at the central drive roUer 92. This sequencing is w..v. ~, achieved using the ~ IU~IU~DDU~ portion 198 of the wntrol system 192 lly depicted in Fig. 12. The U~JIU~__~I, in response to the tie element attachment output signal 226, transmits output signals 322, 324, 326, 328 and 330. Output signal 3æ is imdicative of the stoppage of the stepper motor 102, output signal 324 is indicative of the .~ u ~ c, dies 318, 320 being in their downward position, 20 output signal 326 is indicative of such dies being in their upward position, output signal 328 operates the slitter 312, and output signal 330 advances the tie element web 68, 681 through its next increment. These signals, of course, are ' to position signals associated with the web handling portion of the tie element attachment machine.

WO gS/19259 2 1 8 ~ 9 ` P~ 79 As previously mentione~, and as crh~ ir~lly illustrated in Fig.
1, the tie element attachment portion 60b of the machine 60 is pivotable between -a lowered, solid line op~rating position and a raised, dotted line access position.
According to a feature of the present invéntion, ~ ' control means 331 5 (Fig. 1) are provided to monitor the cu~,~...liv~ operation of the machine portions 60a and 60b when the tie element attachment portion 60b is in its lowered position and the bag web 22 is being leftwardly conveyed a previously described. In the event of a machine '' such as a jalnming of the machine portion 60b, ~r a deviation in onc or both of the bag web loop lengths 10 from its maximum or minimum p. .. :~- .l length, the "y depicted control means 331 are ~Dperative to upwardly pivot the machine portion 60b (by operating suitable drive means not illustrated) to its access position while the bag web æ continues to be produced and run through the machine 60.
To effect tbis automatic upward pivoting of the machine portion 60b, a~ condi~ion signals 331a, 331b are i ' to contrDI means 331 from the r 198, the signal 331a being indicative of sensed operating condition of the machine portion 60a, and the signal 331b being indicative of a sensed operating condition of the machine portion oOb. If either signal 331a or 331b is indicative of a r '- of its associated machine portion the control means 331 output a signal 331c tD energize the '' ~ drive means which, in tum, upwardly pivot the machine portion 60b. The control means 331 may, at this time, also transmit an output signal 331d used to energize an audible alarm (not illustrated).
The overall operation of the machine 60 is adjusted and controlled wo 95119259 2 1 8 1 1 4 9 . ~ J. C- 179 by the main control panel 332 (Fig. 15) which, as seen in Fig. 9, is positioned on the right end of the support frame structure 86. The panel 332 includes heating i ~, t; controls 334, 336 for the tie element weld lines 74 and 78, and the dimples 80, and a heat seal time control 338 for these areas. A length 5 adjustment dial structure 340 is provided for inputting to the machine the length of the individual bags being driven ~ ;Lu..~. To monitor the number of bags which have passed through the machine 60, ~ ul cumulative counters 342, 344 are also provided. Finally, ~lul on-off switch controls 346, 348, 350 are ~ y provided to control the power, tie element 2tt~rhmPnt and 10 transport functions of the tie element attachment machine.
It has been found that an improved tie strap utilizing an adhesive coated elongated tie element with a removable cover strip or a rPr~itinn~l adhesive coated tie element strip without a removable cover strip may be applied to the bags of the continuous process disclosed herein with only minor . ~ of the process. Several variations of tbese adhesive-coated tie straps disclosed im Figures 16, 17, 18, 22 and 23. Insofar as possible, like parts will be referred to with the same numbers having a prime mark.
In Figure 16, an improved elongated tie element strip 62' is shown attached near the open upper end at the side edge portion 42b of a bag B. Bag 20 B is shown as being separated at the 1 ~ cut ]ine Sû from the flattened dual layered web of bags B from the process of Figure 1 as ~ ,' ' by Figures 2 and 3 with the improved tie element strip 62' instead of tie element strip 62. It is I ' ; ~ that the orientation of the folded bag web with or without a gusseted side edge as in Figure 4 is usefully equipped with tie element WO 95/19259 PCI/US9r,100~79 62!. Tie element 621 has an inner end portion 62al, an outer end portion 62b' and an ' portion 352 extending be~ween the inner and outer end .
portions. Elongated st~ap 621 termina~s at a free outer end 354. Tie element 621 has an outer surface and an inner surface. The inner surface facing bag B
is coated with an adher,ive 358 extending from dotted line 356 to outer end 354.
The adhesive 358 is covered with a removable relear,e coated cover strip 360 which covers the entire surface of adhesiw 358. There is no adhesive on inner end portion 62al beyond line 356 which definer, the beginning of inner end portion 62al. The inner end portion is ~ 'y attached to the side portion of the flattened bag body by a means for attaching . , ~ a heat seal or a permanent adhesive. An oval shaped heat seal 362 preferably I ly seals inner end por~,n 62al to both layers of bag edge portion 42b. If the bag edge portion is gusseted as in Figure 4, the inner end of the strap is preferably heat sea'led to all four layers.
lS Flgure 17 shows how the open upper end of bag B is gathered into a circu'lar closed ~ and closed with elongated ~ie element 62' or the thereof. The circular closed . ~ is formed by the user's hand and creates a narrow closed neck where the sides of the bag are brought ;together. Cover strip 360 is easily separated away from adhesive 358 and 20 iremoved. The tacky pressure sensitive adhesive 358 is wrapped around the gathered top of the bag in contact with the outer side surface of the bag in partial u._.L~ lg orientation with itself. rle element strap 621 is long enough to tightly close the top of the bag as shown in Figure 17 with the outer end portion 62b~ u.~ the inner end portion 62a~. The outer surface of the tie element WO 9~/19259 21~ PCT/US95/0/i479 strip is not release coated, and thus adhesive 358 on the inner surface of outer end 62bl sticks well to the outer surface of inner end 62al. The adhesive 358 on the inner surface of the --- " portion sticks to the outer surface of the gathered bag top. Yet it is possible to undo the strap by peeling the outer edge 5 354 in case the bag needs to be reopened by stripping outer end 62b' away from inner end 62al and pulling the tie element away from at least a portion of the outer sur~ace of the bag. Bag B is reclosable by ~ the tie element around the gathered top of the bag to the c~ of Figure 17.
In order to facilitate ~ y of bag B, the last part of outer end portion 62b', say a quarter inch, adjacent outer edge 354, may be bare of adhesive 358 to provide an unsealed flap. The unsealed flap provides a place to grip the outer end of the tie element in order to peel outer end portion 62b' away from inner end portion 62a'. Similarly, an unsealed flap may be provided on the ",~1;1~. -1;....~ of Figures 18, æ and 23. The length of the tie element is selected 15 with respect to the bag so that when the top of the bag is tightly gathered together with the fingers, the outer end portion of the tie element overlaps the inner end portion. For a garbage bag B, this is normaUy a length in the range of 4 to 8 inches.
A, .l;l; -~;.-.~ of the improved -" .~ elongated tie element 62' is shown in Figures æ and 23. ~ Figure 22, a, .l;ri. -l;.. . of the improved adhesive-holding strap is designated generaUy by the reference numeral 62'b. It is the same as tie element 62' e%cept that in this case, beginning at line 356, the inner surface of tie element 62~b is coated with a ~ adhesive 364 aU the way to outer end 354. The bare of adhesive inner end portion 62a' . .

WO95/19259 2181149 r~ r~-,79 -is still fixed at tlhe edge portion 42b adjacent the top of bag B with heat seal 362.
However, the lC~.~;I.iu~ adhesive 364 is selected to only lightly tack (adhere) to the outer surface of bag B. The IqJUi~i~LiU~ adhesive permits tie element 621b to be relatively easily pulled away fr;om the surface of bag B when it is desired 5 to gather up the top and close the bag by wrapping the tie element around the gathered bag. R~citin~l adhesive 364 has the property that when outer end 62bl is overlapped in contact with the outer surface of inne} end portion 62al, a strong not so easily removed bond is created which holds the gathered top of the bag in the enclosed ~ The inner and outer surfaces of the tie element 10 are altered by a treatment means to greatly enhance adherence of an adhesive.
Treatment means, suclh as by corona discharge, of the outer surface of the tie element allows adhesive 364 to adhere much better to tlhe tie element than it does to the bag surface~
Figure 23 shows another ....YI;I~ ;.,.. 621C of the improved adhesively coated elongated tie element of Figure 16 in which adhesive 358 is protected with removable cover $rip 360a from line 356 to its outer end 366 short of outer end 354 of the tie element strap. The only real difference between elongated tie element 621C and tie element 621 is that a small portion of the outer end of cover 360 has been removed. This permits adhesive 358 on tlhe inner 20 (under) surface of outer end portion 62bl to lie in contact with the outer surface of bag B when the strap lays flat again$ the side of the flattened bag. A patch of exposed adhesive extending from end 366 of the cover to end 354 of the tie dement can be adjusted in the amount of exposed area or ~n the strength of the adhesive to tack the ends of tie elements 62~c down, yet permit the tie elements ~ WO 95119259 2 1 ~ t 1 4 ~ -43~
to be separated from the outer surface of the bag without tearing the bag. To facilitate separation of the tie element for use, it can be noted that the porlion of the adhesive covered by removable cover strip 360a, which may be at least several inches long, provides a finger hold to insert fingers for quite easily 5 separating the tacked end portion 62bl from the bag surface.
Figure 18 is another ~ A of the improved adhesively held strap in which the strap 621a is fixed at the side edge portion 42b of bag B by he_t seal 362 at inner end portion 62al. The strap has an outer end portion 62bl which terminates in the free outer edge 354. In the case of elongated tie element 621a, there are t~vo patches of adhesive 368, 372 separated l.~.~ci~ A;-~A11Y by a portion of the tie element, which are designed to overlap and seal when the strap is wrapped tightly around the gathered open top end of the bag. There is an iAner patch 368 on the outer surface of the tie element. Patch 368 has an inner edge 356 ccl~ r ' _ to the line 356 iUustrated in Figure 16 for tie element 621. IiAner patch 368 is covered by a removable cov patch 370 rnade of the same material as cover strip 360. Similarly, the inner surface of outer end portion 62bl is provided with adhesive patch 372 which e~tends to the outer edge or nearly to outer edge 354. Patch 372 may be nearly square having an iiAner edge 374 the same distance from the outer end of the strap as the width of the 20 tie element. Outer adhesive patch 372 may be covered with a removable cover patch 374 which is shown in phantom. In use, both cover patches 370, 376 are stripped off the tie element e~posing the adhesive patches 36~, 372 and the tie element is wrapped around the gathered top of the bag as shown in Figure 17 whereby adhesive patch 372 is brought into ~ contact with patch 368 _ _ wo 95l19259 2 ~ 9 . I/~J ' t - 179 to bond together preventing the bag from coming open.
The polyolefin bags B are produccd b~y the process illustrated in Pigure 1 preferably fro n blown pol~ yl~ .._ fil~. Although the individual bags are shown to be formed with seals forming the tops and bonom placcd transverse S to the 1~ direction in which the bag web is moving, it is to be und~rstood that the individual flanened bags could be formed in an orientation turned nincty degrees from that shown. In such a case, the top and bottom of theindividual successive bags formed on the moving web of bags would have tops and bottoms parallel t~ the direction of movement and the sides of the bags would be formed by seals transverse to the web direction. The tie element anachment machine could then be tumed ninety degrees from the position shown in Figures 1, 9, lO and 21 if it is desircd to attach individual tie elements wherein the tie elements applied lie parallel to the tops of the individual bags to which they are anached. The film, which comprises the flattened bag web, is typically very thin. The strap material is preferably made from a web of P~IJ.,II-YI~ _ material rather than a different material from the bag web to facilitate Iri"u~ g scrap. The strap thickness may be in the range of .0005 to .005 inches, more preferably in the lower end of the range. The strap is preferably made from a higher density higher melt inde~ pol~_ll"~l~ ..c film than that of the bag web material. The tie element is preferably 1/4-2 inches wide and attached between about 24 inches from the top of each bag. The tie element material must have sufficient strength to permit it to be drawn tightly around the gathercd top of the bag and held in place without tearing or breaking. It shouldhave enough strength ~o permit the adhesively coated tie element to be stripped ~WO95/19259 21 8~ p~ ""~ ~79 away from the bag web without tearing or brea~ing. The tie element web can be made from a single or ble~d of resins ~cd or several resins the same or different coextruded into two or more layers. The tie element web is preferably treated on both sides by a treatment such as a corona treatment which 5 enhances adherence. The improved strap material is preferably printed on the outer surface and adb~iYely coated on the inner surface, except for the patch in the " ~ of Figure 18, where in both cases the corona treatment enhamces the adhesion of the printing ink or adhesive, as the case may be.
The suitable adhesive is at least mildly adherent to pvl~
10 film and preferably as thin as possible for c It should not be thicker than the material it is applied to, have high shear strength and not split or separate when the tie element web and its adhesive is pulled away from the bag material after having once been used to seal it.
The term "I~ with respect to adhesive is used in the 15 sense that the tie element with the l~ lA. ' ;- --- -~ adhesive c m be separated from a bag substrate and .~ Yi adhesively a number of times. Another of the l~ l adhesive is that it can be lightly adherent to the bag but have strong adherence to the tie element or to itself. The term l1 in term of art in the adhesive industry. Even though the tie 20 element web with ~ ;.- -l adhesive on one side is easily stripped away from the bag surface, it strongly adheres to the surface of the strap which has been corona-treated for ink adhesion. It also strongly adheres when it is in contact with itself. The fact that the strap is made from a higher melt index polyolefin also enhances adhesion 1.~ because the adhesive has greater adherence wo 9SIl9~9 2 1 8 1 1 ~ ~3 i 1 ~11.)..~5~- 179 than to the lower density polyolefin normally used for thin bag rr~ *~m The backing or cover ~,may be a ~ Liu..~lly release coated paper or ~ul~. IL~I~ . . or any like n aterial.
The adhesive employed in the ' ~ ' of Figures 16, 18 and S 23 can be a conventiollal pressure sensitive adhesive suitable for bonding with polyolefin film. These adhesives are suitably protected with a removable release coated cover strip until use. rv~ ul~Ltiull of such .,u..~...tiu..al a&esives should produce a fairly strong bond with the bag material that can be separated with difficulty in case a user needs to unwrap the adhesive coated tie element to reopen the bag.
The lI,~i~;liU.Ial adhesive used on the modified tie element of Figure 22 has no release coated cover strip. Therefore, it must be easily strippable away from the surface of the bag. An example of a Ic~
adhesive that is believed to be suitable is available from Minnesota Mining and r ~ r ' ' Company (3M), St. Paul, Minnesota, identified as product number 4268-NF industrial adhesive which may be applied by a variety of processes.
Other 3M r "' 1 adhesives can be formulated for the job.
Figures 19 and 20 are schematic j11,.~t~,1;"..~ showing how rolls of tie element web material nnay be produced, although it is understood that other 20 method of applying adhesive, such as spraying may be employed. In Figure 19, a polyolefin, preferably polyc~lyL..~. web 380 is passed over coating roller 382 after suitable ~ . t- " '' '~ for adhesion. The upper side passing over the coating roller may have rrinting applied in line or in a previous operation. Coating roller 382 may be a gravure roller operating in a cu..~,.-Liul-~l =er in pan 384 WO95/19259 21~ r_.,o.,,~o~l7 containing a desired adhesive in solution or dispersion. Distinct bands of adhesive 386, 388 and 390 are applied to the underside of web 380. The web is passed around several rollers and through a drying station 392. Station 392 may employ air or radiant heat to set the adhesive bands on the web.
S Rolls of release coated cover strip are applied over the adhesive at a laminating station 394. Release coated cover strip rolls 396, 398, 400 are applied ~ ly over adhesive bands 386, 388, 390 and pressed against the adhesive bands by roller 402. The tie element web with adhesive bands and release coated cover strips over the adhesive bands are wound as roll 404 on arbor 406.
In Figure 20, semi-finished roll 404 is passed over slitter roll 408 and slitter knives 500 and divided into three separate rolls 641 wound on suitable arbors. Each roll 641 has one of the bands 386, 388, 390 of adhesive, one of the bands of cover strip 396, 398, 400 and an original bare edge portion 502 of web 15 380 without adhesive and without a cover strip. This bare edge portion is the portion of the tie element web that ultimately comprises ilmer end portion 62a' of the attached tie element.
It is evident that similar Wl... ' processes may be employed to produce ~ ;r.~ ~;"--- shown in Figures 18, 22 and 23 of improved adhesive tie strip 62~ of Figure 16. In the case of the ' ' of Figure 18, narrower adhesive bands and narrower release coated cover strip will have to be employed and the adhesive and cover strips are applied to opposite surfaces of bare (or printed) tie element web similar to web 380. With the "~ of Figure 23, a release coated cover strip narrower than the adhesive band may be employed ~181~49 WO9~/19259 1~~ 79 to leave an uncovered end portion. Initially, the whole band may be covered with cover strip which is slit as it is laid down over the adhesive in a process ]ike-Figure 19 and then removed through a pneumatic suction tube when the individual rolls are unwound as shown in~Figure 21. For the "..~T;I~ ,.. Of S Figure 22, the rolls of tie element web may be produced as in Figures 19 and 20 and the release coated cover strip sep~rated away as at roll 2911 in Figures 21 and wound up on a separate arbor (not shown) as rolls 641 are unwound. Any rollerS coming in contact with the adhesive coated side can be coated or wrappedwith a release agent to p~event sticking. It may be desirable to span an endlessTeflon0 coated belt over and around rollers 3041 and 314' to fe~d individual L~ y severed tie element strips to the vacuum belt 316'.
Although the inner end of the tie element shown in Figs. 16-23 is shown to be attached to the side edge of the bag by heat sealing the inner end porlion of the tie elements to the side edge of the bag in its flattened r~ri~tqti~m~
it is within the spirit ~f the mvention to 1 'y affLl~ the inner end portion of the tie element to the side edge of the bags by other me~ms. One of such means is to apply an adhesive layer, especially a heat setting adhesive layer tothe irmer surface of the ilmer end portion of each tie element. This inner end , portion cOn then be ~r~qnq~rted as a tie element web 1~ ly in the bag web direction in the ma~mer of Figs. 10 and 21 to a position wherein the inner end portion of i .~ severed tie element strips c n be pressed and/or heated in contact with the 'y stopped bag web at side edge portions thereof to ~~ affL~ the inner end portion of a separated elongated tie element to each of successive bags. Such tie elements employ a non-heat setting ;

~ wo 95/19259 21 8 114 9 r~l~c ~ ~ ~ 179 adhesive to wrap and seal the gathered top of bags as disclosed in Figures 16, 17 18, 22 and 23, the only difference being the use of adhesive to I 'y attach the inner end of tie elements to individual bags instead of a heat seal.
Il~e foregoing detailed description is to be clearly I ' ~ as 5 being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.

Claims

I claim:

1. A flexible bag having an integral closure element, of the type which is closed by gathering the top of the bag into a circular closed configuration and holding the top of the bag closed with the closure element, comprising:
a tubular bag body having a closure across one end to form a closed bottom and an opposite open top, the tubular body, when laid flat, having opposite side edges separated by sidewalls of the tubular body with side edge portions extending from bottom to top along said side edges;
an elongated adhesively coated flexible tie element having an inner end portion permanently affixed to a side edge portion of the tubular body near the open top;
said tie element being adapted to wrap around the gathered top of the bag and partially overlap upon itself to adhesively hold the gathered top of the bag in a closed configuration.

2. The flexible bag of claim 1 wherein the inner end portion of the tie element is bare of said adhesive and affixed to the side edge portion of the tubular bag body by heat seal means.

3. The flexible bag of claim 2 wherein the elongated adhesively coated tie element has an inner surface facing a sidewall of the bag body having said adhesive coating and a removable release coated cover strip over said adhesive coating which permits the tie element to lay against said sidewall without adhering.

4. The flexible bag of claim 3 wherein said elongated tie element has an outer end portion and an intermediate portion extending between the inner and outer end portions wherein said adhesive coating and said cover strip extend along the intermediate and outer end portions.

5. The flexible bag of claim 4 wherein said outer end portion includes a patch of said adhesive coating not covered by said release coated cover strip, said patch facing the sidewall of the bag body and serving to tack the outer end portion of the tie element down against the bag.

6. The flexible bag of claim 4 wherein the adhesive coating on the inner surface of the elongated tie element does not go all the way to the end of said tie element, leaving a bare unadhesively coated flap at the end which facilitates gripping the outer end of the tie element to reopen the bag after it is closed.

7. The flexible bag of claim 2 wherein said elongated tie element has an inner surface facing a sidewall of the bag body and said adhesive is a repositional adhesive on the inner surface adapted to lightly but removably adhere the tie element in a flat configuration along said sidewall.

8. The flexible bag of claim 7 wherein the elongated tie element has an outer surface opposite said inner surface, the outer surface being altered by treatment menas for enhancing adherence of the repositional adhesive when the tie element is wrapped around the gathered top of the bag and the repositional adhesive is brought in overlapping contact with the altered outer surface.

9. The flexible bag of claim 8 wherein the adhesive coating on the inner surface of the elongated tie element does not go all the way to the end of said tie element, leaving a bare unadhesively coated flap at the end which facilitates gripping the outer end of the tie element to reopen the bag after it is closed.

10. The flexible bag of claim 2 wherein said elongated tie element has an inner surface facing a sidewall of said bag body and an opposite outer surface, each of said surfaces having a relatively small patch of adhesive separated by a longitudinal portion of tie element and positioned to come into contact with each other and seal when the tie element is wrapped around the gathered top of the bag to close the bag.

11. The flexible bag of claim 10 wherein said relatively small patches of adhesive comprise a first patch on the outer surface adjacent the inner end portion of the elongated tie element and a second patch on the inner surface located at an outer end portion of said tie element.

12. The flexible bag of claim 10 wherein each of said relatively small patches of adhesive is protected by a removable cover patch to prevent the tie element from sticking to the sidewall of the bag body to which said elongated tie element is attached or to another of said bags.

13. The flexible bag of claim 11 wherein each of said relatively small patches of adhesive is protected by a removable cover patch to prevent the tie element from sticking to the sidewall of the bag body to whcih said elongated tie element is attached or to another of said bags.

14. The flexible bag of claim 1 wherein said tubular bag body is a polyolefin plastic and said elongated flexible tie element is made from a polyolefin plastic with its surface altered by a treatment means to improve adhesive adherence.

15. The flexible bag of claim 3 wherein said tubular bag body is a polyolefin plastic and said elongated flexible tie element is made from a polyolefin plastic with its surface altered by a treatment means to improve adhesive adherence.

16. The flexible bag of claim 15 wherein said polyolefin plastic is polyethylene.

17. The flexible bag of claim 7 wherein said tubular bag body is a polyolefin plastic and said elongated flexible tie element is made from a polyolefin plastic with its surface altered by a treatment means to improve adhesive adherence.

18. A flexible plastic bag having an integral closure element, of the type which is closed by gathering the top of the bag into a circular closed configuration and holding the bag closed with the closure element, a flattened tubular plastic film bag body having a closed end, an openable end, a side edge portion extending between said closed end and said openable end, and an outer side surface bounded by said side edge portion to form a flattened bag;
an elongated flexible bag tie element extending across said outer side surface adjacent said openable end of the plastic film body, said tie element having a length defined by an inner end portion, an intermediate portion and an outer end portion and having an inner surface along said length facing the outer side surface of the flattened tubular plastic film bag body and an outer surface opposite said inner surface;

means for firmly anchoring the inner end portion of the tie element to the side edge portion of said plastic film bag body adjacent said openable end;
said tie element being adhesively coated and adapted to wrap around the gathered circular top of said film bag body and partially overlap in adhesive contact with itself to hold the gathered top of the bag in a dosed configuration.

19. The flexible bag of claim 18 wherein said outer end portion of said tie element has an extending flap portion which does not adhere to itself when wrapped in said closed configuration around the top of the bag, said flap being suitable to grasp in order to more easily reopen the previously closed bag.

20. The flexible bag of claim 18 wherein the said tie element has an adhesive coating on the inner surface extending along the intermediate portion and the outer end portion and a removable release coated cover strip over said adhesive coating.

21. The flexible bag of claim 20 wherein the outer end portion includes a patch of said adhesive coating not covered by said release coated cover strip, said patch facing the sidewall of said bag and serving to removably tack the outer end portion of the tie element against the bag.

22. The flexible bag of claim 18 wherein said adhesive coating is a repositional adhesive coating on the inner surface adapted to lightly but removably adhere the tie element in a flat configuration along the side of said flattened bag.

23. The flexible bag of claim 22 wherein said outer surface of the tie element is altered by treatment means for enhancing adherence of the repositional adhesive when the tie element is wrapped around the gathered top of the bag and the repositional adhesive is brought into overlapping contact with the altered outer surface of the tie element.

24. The flexible bag of claim 23 wherein the outer end portion includes a bare flap of uncoated material which facilitates gripping the outer end of the tie element to reopen the bag after it is closed.

25. The flexible bag of claim 18 wherein each of said inner and outer surfaces of said tie element have a relatively small patch of adhesive separated by a longitudinal portion of tie element and positioned to come into contact with each other and seal together when said tie element is wrapped around the gathered top of the bag to close the bag.

26. The flexible bag of claim 25 wherein said relatively small patches of adhesive comprise a first patch on the outer surface adjacent the inner end portion of the elongated tie element and a second patch on the inner surface located at an outer end portion of said tie element.

27. The flexible bag of claim 26 wherein at least one of said relatively small patches of adhesive is protected by a removable cover patch to prevent the tie element from sticking to the side wall of a bag.

28. A method of attaching adhesively coated elongated tie elements to longitudinally conveyed flattened tubular plastic web of flexible bag material having a series of successive plastic bags defined thereon, comprising:
conveying said web of flexible plastic bag material in a longitudinal direction;
providing a lengthy supply of adhesively coated flexible tie element web stock having a longitudinally running band of adhesive and an attachment edge portion free of said band of adhesive;
moving said tie element web stock along a controlled path to a location where said attachment edge portion is positioned over said web of flexible bag material;
transversely severing successive individual elongated tie elements from said tie element web stock;
momentarily stopping portions of said web of flexible bag material comprising successive ones of said plastic bags defined thereon under successive ones of said transversely severed individual elongated tie elements; and firmly anchoring said attachment edge portion of an individual elongated transversely severed tie element to each of said plastic bags while a portion of said web of flexible bag material is momentarily stopped.

29. The method of claim 28 wherein:
the series of successive plastic bags defined on said longitudinally conveyed web of flexible plastic bag material have a top, a bottom and opposed side edge portions;
said attachment edge portion of said tie element web stock becomes an inner end portion of said successively transversely severed individual elongated tie elements, the step of moving said tie element web stock and the step of momentarily stopping successive ones of said plastic bags under successive transversely severed individual elongated tie elements are performed in such a way as to successively place said inner end portion above a side edge portion of each bag adjacent the top of each bag.

30. The method of claim 29 wherein the step of firmly anchoring, firmly anchors said inner end portion of one of said tie elements to the side edge portion adjacent the top of each of said defined bags.

31. The method of claim 28 wherein the step of firmly anchoring includes heat sealing said attachment edge portion of said tie elements to said bags.

32. The method of claim 30 wherein the step of firmly anchoring said inner end portion of each of said successive tie elements to the side edge portion of each of said successive bags is performed by a heat sealing step.

33. The method of claim 32 wherein said heat sealing step performed in a manner to form a roundedly shaped heat seal area in order to increase strength and prevent tearing.

34. The method of claim 28 wherein:
the step of providing a lengthy supply of adhesively coated flexible tie element web stock with a longitudinally running band of adhesive and an attachment edge portion free of said band of adhesive includes the step of providing a removable release coated protective cover strip over said band of adhesive; and the step of firmly anchoring said attachment edge portion of an individual elongated transversely severed tie element to each of said plastic bags while a portion of said web of flexible bag material is momentarily stopped, includes the step of laying said individual tie elements with said protective cover strip flat against an outer surface of said plastic bags so that said tie element can be lifted from said outer surface without sticking.

35. The method of claim 34 wherein said elongated tie element has an outer end portion opposite said attachment edge portion which includes a small portion of said adhesive band which is not covered by said protective cover strip; and said step of firmly anchoring said attachment edge portion of said individual tie elements to successive bags and laying them flat against an outer surface of said bags includes the step of simultaneously causing said small portion of said adhesive to be removably adhered to said outer surface to hold each successive tie element in a flat orientation against each of said bags.

36. A method of preparing a lengthy supply of pressure sensitively coated flexible tie element web stock having a band of adhesive running longitudinally along said web and an attachment edge portion free of said band of adhesive, from which transversely severed individual elongated tie elements can be made for anchoring said attachment edge portion to the side of a flattened tubular web of flexible plastic bag web material on which successive bags are defined, wherein the bags when individually, separated can be closed by gathering a neck at the top of the bag and winding the adhesively coated flexible tie element around the gathered neck in at least partial overlapping orientation with itself, comprising:
conveying in a longitudinally direction a lengthy thin plastic film tie element web stock having an outer surface and an inner surface;
employing a treatment means to alter at least one surface of said longitudinally conveyed web to improve adherence of an adhesive;
applying a continuous band of pressure sensitive adhesive to a portion of the web width along the inner surface, said band being laterally offset to leave an attachment edge portion of said web free of said band of adhesive;
attaching a removable release coated protective cover strip over said band of adhesive; and winding said web of adhesively coated tie element web stock on an arbor.

37. The method of claim 36 wherein said step of applying adhesive applies a repositional adhesive which is easily removable from said plastic bag web material, said treatment means being applied to said outer surface of said tie element web stock to which said repositional adhesive will adhere well when wound around a gathered bag top to partially overlap itself.

38. The method of claim 36 wherein multiple bands of said adhesive are applied at laterally spaced locations along said inner surface, separated by unadhesively coated portions of said tie element web to serve as an attachment edge portion when said tie element web having multiple bands is separated into individual rolls of adhesively coated tie element web stock.

39. The method of claim 38 wherein said web having multiple bands of adhesive on said inner surface is separated into individual rolls of tie element web stock each having a band of adhesive and an attachment edge portion free of said band of adhesive.

40. The method of claim 36 further including the step of applying a band of pressure sensitive adhesive on the outer surface of said web.

41. The method of claim 40 wherein said bands of adhesive being applied on said inner and said outer surface are relatively narrow bands spaced apart laterally and separated by a portion of said web stock free of said bands of adhesive.

42. The method of claim 41 wherein said narrow band of adhesive being applied on said outer surface is positioned adjacent said attachment edge.