CA1116207A - Web transporting device - Google Patents

Abstract

WEB TRANSPORTING DEVICE
Abstract A material transporting device is disclosed wherein a web material is pneumatically moved along shaped, louvered, surfaces and is collapsed to exit from the device in a narrowed pattern. Use of the device is particularly directed to rapid handling of scrap web material.

Description

WEB TRANSPORTING DEVICE
Description Technical Field In manufacturing and handling webs of flex-ible material, simple and rapid removal of scrap isvery important to e~ficient operation. In fact, the rate of manufacture or handling of wide webs of film material is often controlled by the ease with which scrap can be removed in case o~ a break in the web.
Such removal, in the case of ~ilm web handling, in-cludes a collapse or convergence o~ the web into a narrower form. For films of relative thin gauge, the collapsed or converged film can be characterized as a rope of material. For some film webs, particularly of heavy material, lt has been found that pleating the web results in effective collapse and convergence.
~his invention, thus, relates to roping and pleating webs of material and to devices for performing the roping and pleating.
Background Art Pneumatic transport of webs, parts of webs, or small articIes has been previously disclosed.
U. S. Patent No. 3,070,901, or example, discloses that webs can be guided along a certain ," 1 ~ ~:

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path by means of a plurality of lndividual blower devices, some directing air transverse to the direction of travel. Louvers disclosed in that patent extend across the device and there is no disclosure of web material pleating.
U. S. Patent No. 3/705,676 discloses a con-veyor which utilizes widely spaced air nozzles extend-ing across an otherwise closed plenum chamber. The device is disclosed to be useful for removing web trim and for threading paper ribbon to start a paper ma-chine. There is no disclosure of wide web transport or material collapse.
U. S. Patent No. 2,848,8~0 pertains to a web conveying device utilizing force from a gaseous medium.
lS The device includes ducts for the gaseous medium having apposing vented faces forming a channel through which a web is conveyed. Louv2rs are not specifically disclosed and there is no hint of web collapse.
U. S. Patent No. 3,180,688 pertains to a conveyor with an air feed plenum having both perfora-tions and slits, to provide lift and propulsion, re-spectively, to materials transported in the conveyor.
The conveyor is walled with an open top. There is no web collapse.
U. S. Patent No. 3,181,916 pertains to a conveyor for small articles and includes an air plenum ;~
with one louvered surface. The louvered surface is walled with an open top and serves as the floor for ar~icle conveyance. There is no web material con-veyance and no hint that webs, if conveyed, could be collapsed.
" U. S. Patent No. 3/999,806 describes an air-driven conveyor for individual parts or articles wherein there are integral Y-shaped spur sections in the conveyor. The conveyor includes a deck with an . . , ~ ;.,;, ~ , , underlying plenum section and holes in the deck, of certain configuration. The deck, in straight sections of the conveyor, includes a combination of lifting holes and propulsion slots and the spur sections have only propulsion slots. There is no mention of web transport or of collapsing materials transported.
Summary of the Invention According to the present invention, there are provided web material transporting and collapsing devices comprising: at least one air feed plenum having an inlet end and an outlet end; a surface on the plen~m; a multitude of slots with louvered openings in the surface, said louvered openings directed toward the outlet end; and means for applying transverse forces along the surface of the plenum to a web material transported in the device to collapse the web material. A process is provided for collapsing a moving web of material comprising applying longitud-inal pneumatic force to a wide web of the material to hold the web under tension; applying transverse forces to the web under tension to collapse the wide web;
moving the web in the direction of the tension to continually apply longitudinal and transverse forces to the moving web.
There is further and more specifically pro-vided a material converger comprising: an air-feed plenum having an inlet end and an outlet end; a sur-face on the plenum decreasing in width from the inlet end to the outlet end; a multitude of slots with louvered openings in the surface, said louvered open-ings directed toward the outlet end. ~here i5 also provided a web material waste hand]ing apparatus com-prising a wide web delivery means operatively engaged with a material converger to receive and collapse wide web material, the converger, in turn, operatively :: , : ~ :, ,:

engaged with a comminuting means to receive collapsed web material. A process is provided ~or converging a moving web of flexible material comprising applying longitudinal pneumatic force to a wide web of the ma-terial to hold the web under tension; applyingbalanced transverse forces toward the center of the web under tension over a predetermined length of the web to converge the wide web into a roped structure;
moving the web in the direction of the tension to continually apply longitudinal and transverse forces to the moving web; whereby the wide web is contir,ually converged to a roped structure.
There is further and more specifically pro-vided a pleating device comprising: a first air feed plenum having an inlet end and an outlet end, a trans-versely irregular surface on the first plenum, flat at the inlet end and progressing over the length of the surface to at least one peak at the outlet end; a second air feed plenum having an inlet end and an outlet end, a transversely irregular surface on the second plenum, mating with the sur~ace of the first plenum and juxtaposed in a spaced--apart relation thereto; a multitude of slots with louvered openings in each irregular surface, said louvered openings directed toward the outlet ends. A process is pro-vided for ~leating a moving web of material comprising applying longitudinal pneumatic force to a wide web of the material to hold the web under tension; applying transverse pleating forces to the web under tension over a predetermined length of the web to collapse the wide web into a pleated structure; moving the web in the direction of the tension to continually apply longitudinal and transverse ~orces to the moving web;
whereby the wide web is continually collapsed to a pleated structure.

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Brief descriptlon of the Dr~wings Embodiments of the invention Are lllustrated in the accompanying drawings wherein;
Flg, 1 ls a top plan view of a material converger of this invention, Fig. 2 is a cross-sectional view of a mate~ al converger of this invention;
Fig, 3 is a cross-sectional view o~ a mate~ a~
converger of this invention having two air-~eed plenums;
Fig, 4 is a longitudinal cross-sectional view oI' a louvered portion of a materlal converger of this invention;
Fig~ 5 is a eut~awAy section of the side of a material converger having both, an air ~eed plenum and a material f~ed .
plenum;
Fig, 6 is a cut-away section of the side of a materlal converger having an air feed plenum and material guideæ;
Fig~ 7(a~ is a side view repre~entation OI A web pleater of this invention;
Figo 7 (b) is a top view repres0ntation of a web 20 pleater o~ this invention;
Fig. 8 i~ a perspective vlew of a web pleater of this invention;
Fig 9 i~ an exploded p~r~pective view of a web pleater o~ this invention, ~5 Fig. 10 is a cross-sectional view of a louvered portion of a web pleater o~ thls invention;
Fig~ 11 is a vicw of the inlet end of a web pleater Or this invention;
Fig. 12 is a vlew of the outlet end o~ a w~b pleater 30 of this inventlon~
Figs. 13-16 are views of additional outlet end~ o~
web pleaters of this invention;
- ~ig. 17 is a perspective view of another web pleater o~ this invention;
Fig. 18 i9 an exploded per9pective vlew o~ a web pleater of this invention having compound surface~, Fig. 19 is ~n exploded end vlew o~ the device o~
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- -Disclosure of the Invention Referring to Fig. 1, material converger 10 includes an inlet conveyor unit 11, a converger unit 12, and an outlet con~eyor unit 13. Each unit incLudes slots 14 with louvered openings cut into surface 15 and arrayed at angles of 90 degrees or less with the direc-tion of material transport. In the conveyor units 11 and 13, the slots 14 with louvered openings are cut generally perpendicular to the unit edges and per-pendicular to the direction of material transport. Inthe converger unit 12, the slots 14 can be cut either perpendicular to or at an acute angle with the intended direction of material transport. Using the center line 16 of the converger unit as a reference line, the slots 14 can be cut at an angle 17 of from about 30 to 90 degrees with angles of from about 40 to 60 being preferred for material convergers which utilize slots cut at acute angles. Slots 14 in converger unit 12 need not be perpendicular to the unit edges and slots cut at different angles can be used in a single unit.
Web 18, shown to be transparent, is delivered to con-verger 10 from a wide web delivery means, not shown.
In operation, the web continuously traverses inlet conveyor unit 11 in flat form, converger unit 12 under collapsing forces to yield a rope, and outlet conveyor unit 13 in roped form. In roped form, web 18 can be easily handled such as in a web material waste handling apparatus, the roped structure can be introduced directly into a comminuting means, not shown.
Reerring to Fig. 2, material converger 10, including inlet conveyor unit 11, converger unit 12, and outlet conveyor unit 13, is represented in a cross-sectional side view. In these Figures, slots 14 in surface 15 are represented in an oversized . - . :., . . :
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Z~i manner to indicate the direction of louver openings.
The body of inlet conveyor unit 11 is an air feed plenum and, under operational air pressure, air is ~orced through the slots 14. In the same way, air is forced through the slots 14 in the converger unit 12 and the outlet conveyor unlt 13. Air, thus moving through slots 14 provide longitudinal pneumatic forces to hold web 18 under tension; and, in the case of slots 14 cut at an angle, the air also provides transverse forces which, when balanced on each side of a center line on surface 15, converge and collapse web 18. Increase in depth of the plenum with decreasing width can be used to aid in maintaining a balanced air flow through the material converger. The width of surface lS in conveyor units is constant from end to end, and in converger units decreases in the direction of material transport.
Fig. 3 represents a cross-sectional view of a material converger 10 with two air feed plenums.
Individual elements of the converger correspond to elements previously identified in Fig. 2. The material converger 10 of Fig. 3 incLudes two single plenum con-~ergers positioned surface-to-surface (15-15) and spaced apart to leave channel 19 through which web material is conducted and converged. Channel 19 can be made to increase in depth with decreasing width to ac-commodate transport of web material as the web is con-verged into a roped form.
Fig. 4 represents a cross-sectional view cut through slots 14 in a portion of surface 15 of a con-verger unit 12. Arrow 20 indicates the direction of air flow and consequent direction of material trans-port under operational air pressure.
Fig. 5 represents a partially cut away side view of a material converger 10 including inlet , ~ ~

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conveyor unit lla, converger unit 12a, and outlet con-veyor unit 13a. The bodies of the conveyor units lla and 13a and the converger unit 12a in this Fig. 5 include air feed plenum 21 with material feed plenum 22 mounted thereon. Material feed plenum 22 is shown to have increased depth with decreased width to facil-itate handling of wide web material in roped form.
Surface 15 forms a common wall between air feed plenum 21 and material feed plenum 22.
Fig. 6 represents a partially cut away side view of a material converger incl1~ding inlet and out-let conveyor units 11 and 13, converger unit 12, sur-face 15 and slots 14, as previously described. The material converger of this Figure also includes mater-ial guides 23 which are walls extending upward from and defining the lateral edges of the surface 15~
The material yuides serve a dual purpose.
First, the guides prevent web material from running off of the converger during operation, especially during start-up while threading a web through the converger device. Second, the guides aid in converging, collaps-ing, and roping web material moving through the con-veyor by providing transverse forces toward the center of the web material. The aid provided by material guides in collapsing web material is especially important in operation of converger units having slots perpendicular to the direction of material transport and in handling web materials having a stiffness too great for ready collapse by air forces alone.
Convergers having slots cut perpendicular to the direction of material transport are constructed with material guides along the converging sides of the unit. Convergence or roping of a moving web is ac-complished by contact of the web with the material guides. In such convergers, web roping is dependent , .
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upon the combination of transporting force provided by air passing the louvers a~d con~erging force pro-vided by physical contact between the web and the material guides.
Convergers having angled slots can also be used with material guides along the converging sides of the unit. Such convergers are ideally suited for roping webs of film having a stiffness such that the material guides provide converging forces by contact between the film and the material guides.
Convergers having slots cut at an angle with the dir~ction of material transport can be used without material guldes, if desired. In such con-veyors, roping of a moving web is accomplished by angled forces from the louver openings.
Material guides can be straight or curved, perpendicular or angled with the louvered surface.
The guides can be walls of any effective height depend-ing on the requirement of a particular use; such heights ranging from a mere rib tracing the pattern of the louvers to curved walls angled upward and to-gether to yield a closed material feed plenum.
Material guides can be ormed from louvered surfaces angled upward and equipped as air plenums such that the material guides also operate as conveying surfaces.
~eferring to Figs. 7(a) and 7(b), web pleater 24 is shown in a simplified representation with flat web 18 entering the pleater and collapsed, pleated, web 18(a) leaving the pleater.
Fig. 7(a) represents a side view of pleater 24 including first air feed plenum 25 and second air feed plenum 26. The air feed plenums are juxtaposed in spaced-apart relation to leave a channel denoted by inlet end 27 and outlet end 28. Flat web 18 enters pleater 24 at inlet end 27. As the web is ' . ' i , " .
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transported through pleater 24, it is, itself, pleated and emerges at outlet end 28 as pleated web 18(a).
Fig. 7(b) represents a top view of pleater 24 looking down on air feed plenum 2~, Phantom lines 29 indicate the location of pleats formed in flat web 18 as it progresses through the channel from inlet end 27 to outlet end 28 emerging as pleated web 18(a).
FigO 8 is a perspective representation of web pleater 24 with flat web 18 passing into inle~ 27 and pleated web 18(a) passing out of inlet end 28.
Air feed plenum 25 and air feed plenum 26 are juxta-posed and have apposing surfaces which are fan pleated commencing at the inlet end with a flat sur-face and progressing to the outlet end with fullsurface pleats. The pleats of each surface mate in a spaced-apart relation. Pleat trough 30 and pleat peak 31 in plenum 25 mate with pleat peak 32 and pleat trough 33 in plenum 26 to yield a channel for the transport of web material.
Fig. 9 is an exploded perspective represent-ation of web pleater 24 showing air plenums 25 and 26 with transversely irregular surfaces 34 and 35. While a variety of transversely irregular surfaces 34 and 35 can be utilized, for purposes of description, the surfaces shall be sometimes characterized herein as an pleated. The inlet edge 36 of surface 35 on plenum 26 is substantially flat. The outlet edge 37 of sur~
face 35 on plenum 25 is irregular. Surface 35 is, ; 30 thus, pleated with folds which commence at the inlet edge 36 and progress over the length of surface 35 to the outlet edge 37. Such fan pleated surface 35 of plenum 26 is matched by an pleated surface 34 of plenum 25 to mate therewith when the plenums are jux-taposed in surface-to-surface spaced-apart relation.

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Although not a requirement of the pleating device of this invention, it is preferred and generally the case that the distance along the flat inlet edge of a fan pleated surface is about equal to the distance along the pleated outlet edge of that surface.
Fan pleated surfaces 34 and 35 are shown with a representation of slots 38 cut into the surface.
Slots 38 are used to direct a gas flow from inside plenums 25 and 26 along the surfaces 34 and 35 toward the outlet edges of thos~ sur~aces. Gas, thus directed, exerts transporting forces on web material located be-tween the plenums. Web material, under the influence of the gas transporting forces, is contacted by the pleated plenum surfaces which exert transverse forces on the web to cause orderly web collapse, herein termed pleating.
The source of gas and pressure means for directing the gas are not shown. Gas can be supplied by fans or other means and can be introduced into the plenums by any means and at any locations. The plenums can have closed ends as shown in Fig. 8 or open ends as shown in Fig. 9. Web pleating plenums having open ends can be operatively joined with plenums from other pneu-matic web conveying devices. The plenums must be otherwise sealed to permit an inside-to~outside pres-sure differential adequate to maintain flow of gas through the slots at a velocity greater than the in-tended web velocity for web transport. Gas supply can be introduced at a plenum end or through holes in any flat plenum surface~ Gas supply and gas velocity should be adjusted to be nearly the same for mating plenums in order to balance forces on web material in the channel between the plenums.
If desired or required, vents or other open-ings for emergent gas can be provided in addition to " ~, :
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tne slot openings. For example, the web pleater can be joined with pneumatic conveyors which conveyors can supply gas pressure at the pleater inlet ends and can utilize gas pressure at the pleater outlet ends.
Fig. 10 shows a cross~sectional view of a representative fan pleated surface of a web pleater, for example, surace 35, sectioned through slots 38.
Arrow 39 indicates the direction of gas flow and con-sequen~ direction o~ web transport under operational gas pressure.
Fig. 11 is a representation of a shape for an inlet end 27 of a web pleater of this invention. The inlet end 27 is bounded by flat inlet edges of plenum surfaces 34 and 35 and represents the channel for introducing flat web into the web pleater. While not necessary for operation of ~he web pleater, it is sometimes advantageous to locate shoulders 40 at each end of inlet 27. Edges of some scrap web material are sometimes stiff and unmanageable and provision for en-larged edge channels over the length of the pleatingdevice accommodates such stiff material.
Fig. 12 is a representation of a shape for an outlet end 28 of a web pleater of this invention.
The outlet end 28 is bounded by pleated outlet edges of plenum surfaces 34 and 35 and represents the chan-nel for releasing pleated web from the web pleater.
The channel of this Fig. 12 exhibits t~o peaks and results in collapse of a flat web to about one-half of its original width. The degree of flat web col-lapse depends, generally, upon the number of peaksand the length of channel between peaks.
Fig. 13 is a representation of an outlet end 28 having one peak and resulting in collapse of a flat web to about one-half of its original width.
Fig. 14 is a representation of an outlet end , ... ,- : ~
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32~7 ~8 having three peak~ and Fig, 15 is a ~imllar representation demonstrating ~hat the peaks can be trunca-ted or rounded, Fig.
16 ls a representation o~ an ou~let end 28 having three peaks in a channel made from circular element~.
Fig, 17 i~ a perspective repre~entation of a web pleater 41 with flat web 1~ passing into inlet end 42 and pleated web 18 (a3 passing out of lnlet end 43. Air feed plenum 44 and ~ir ~eed plenum 45 are ~uxtaposed and havlng apposing surfaces with a single, round, pleat commencing at inle~ end 42 wlth a ~lat sur~ace and progressing wl~ increasing curvature to`the outlet end 43~ Alr plenum 44, at the outlet end 43, is shown to h~ve an inverted "U" shape, Air plenum 45~
at the outlet end 43, ls shown to be a solid sh~pe with one sur-face rounded to mate with the apposing 3urface of plenum 44.
The ~oli~ shape could, o~ course, be an inverted "U" shape~
Air plenums 44 and 45, at the outl~t end 43~ can have more than one peak, such as by having the shape of an "M".
Fig. 18 is ~n explo~ed perspectlve representatlon of a web pleater 46 showing air pienum3 47 and 48 wlth transversely t irregular surfaces 49 an~ 50, Transver~ly irregular ~urface~ ~9 and 50 have compound cur~e~ whèrein the tran~ver~e p~eating cur~e progressively lncreages over the l~ngth of the surfaces and the sur~aces thems~lves are curvllinear along their length. By curvilinear, is meant that a line 1 from a point 54 along inlet edge 51 to a corresponding poin~ 55 along outlet edge 56 is a : curved llne . In this drawing, to enable more c omplete under-standing, phantom Iin~ are inserted to provide indicati on of all edges of the pleater. The ~nlet edge 51 of sur~ace 5Q on plenum 48 is substantially flat; and the outlet edge 56 of pl~num 48 is irregular and directed in a plane different fro~ th~t oi thè inlet edg~ 51. Sur~ace 50 i~, thus, pleated with a single~
- ~ounded, pleat in a compound curvilinear surfac@ wh~ch commence6 at the inle~ edge 51 and progre~9e9 over the length of ~ur~ace 50 to the outlet ~dge 52, Such pleated ~urface 50 o~ plenum 48 is matched by pl~ated sur~ace 49 o~ plenum 47 to mate ther~with when ~he plenums are juxtaposed in surface~to~sur~ace ~paced-apart relation. A web to be cQllap~ed, when tran~ported ;

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through the a~embl0d pleater of Flg, 18~ 13 pleated lnto the shape of an inverted "U'l and is also twisted into a dlffer2nt plane.
Fl~. 19 is an exploded end view represenk~tion of web pleaker 46 in Figo 18. Plenums 47 and 48~ with sur~ces 49 and ~0 having slots 14 cut therein, are mounted wlth sur~ace~
49 and 50 in parallel spaee~ apart relation ~uch that when a web is introduced between inle~ sdges 53 and 5~ and when alr i8 direc-ted through the plenums 47 and 48, the web is drawn between ~nd along surfaces 49 and 50 and is simultaneously ple~ted and curved downward to eoll~pse the web and alter its direction.
The transver~ely irregular, fan pleated surfaces of the web pleater o~ th~s invention can include o~e pleat or several and the plea~s can be p~aked wi~h sharp e~ges or can ~e trunc-ated or round.
In operation, a gas pressure is provided in theplenums of the inventian by means of fan~ or the like. For reasons o~ economy, alr is ~he gas most often used although any other ~uitable gas or combination o~ gase~ would be effective.
Additiv~s c~n b~ combined with the gas to accomplish some tre~-ment and the g6lS can be heate~ or cooled to alter temper~tures or to dry pleated materialO The ga~ pressure must be suf~icient to move gas through the plenum~ at~a velocity greater than the desired rate o~ web transport, Web transport, in the case of scrap r~moval, can be re~uired to be as great a3 about 1000 meters per minute. Due to the ea~e of web handling provided by the devices of this lnve~-tio~, the devices are also u~ful at low we~ tran~port speeds, ~or instance, as slow as about 15 meters per ~inute.
The devic~s of thi~ invention are ~elf~starting. In the ca~e of the web pleater, introduction of an end length o:P
w~b mate~ial into the pleater c ommences collapse and tranæport of the web.
In the case of the materlal converger, the 9elI
35 starting capability is ~mproved i:f the inlet end of th~ device - includes at least two air ~eed plenums h~ving æur~aces in ,~uxtaposed, spaeed-apart, r~lation, wi th the louvered openln~;s directed in concertO It has al80 been found helpful to fit the outlet end o~ the material converger with a material feed plenum or an a~r fee~ plenum to assist in continuous oper~tion through gaps in material supply caused by breAks ln the web, Self-starting is an important ~eature where nearly inst~ntan~
eous web scrap remova~ is necessary ln hlgh speed f~lm handllng processe~.
Collapse and transport of web ma~erials can be con ducted with the surface of the device ln any attitud~ -- verticalg horizontal, or any intermed~ate position -- and in a flat or cur-vilinear shapeO The material converger can be effectlvely operated with a surface wh~ch exhibits curve either to the right or to the left on ~he hor~zon~al plane and curve o~ either in~
side or outside rad~u~ on the vertical plane.
Louver~ in the ~urface of the plenum~ are formed from slots cut ~n the surface and opened in the direction o~ intended material travel. Louver~ direct the gas nearly flat along the surface, The louver openings are preferably belo~ and are nearly perpendicular wi~h the surface. Arrays of louvers can be in any pattern and ean have any length and ~pacing within the followlng general llmits The louver~ are less than 25 cent~meters and pre~erably from 2 to 15 centimeter~ long. The length of the louvers is less than one-fourth the width of the total sur~ce. Each louver should have more than one neighboring louver at least one-fourth louver length but less than three louver lengths away.
Louver length and sp~cing is important to maintain a stable and rapid movement of web mater~al. Louvers whlch are too long or which are æpaced too closely permit an ex-cessive ~low of gas from the plenum resulting in exces~ivelyreduced ga pressure farther along the plenum, Such excessively reduced gas pressure provides inadequate force for continued pleating and transport o~ the material. Louv~r~ which are too short or which are spaced too far apart prev@nt gas flow adequate to provide materi~l collap~e ~nd transport~
As a general rule, louvers at th~ inlet end of ~ e '~ device should be relatively closer to~ether than louver~ at .

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the outlet end. Such progr~ssiv~ly ~reater spacing between louvers i3 believed to aid in balancing gas flow khrough the device and in devcloplng a higher init-lal tension in web mat-erial entering the device.
Mating plenums ~paced ~p~rt to make the web pleater Or this invention ar~ spaced near enough to a~ford adequate pneumatic transporting forces to move the web and are spaced far enough to provide room for movement of the web without hang-up in ~he plenum sur~ace~O The pre~erred distance between the plenums is different ~or d~f~erent we~ materials and op-erating conditions. The distance can vary from one pleater to another within ~ range of about 2 to 25 centimeters~ tances of-from 5 to 15 centimeters have been found particularly suited for plea~ing webs of polyethy~ene te~eph;thalate from 25 ~o 350 microns in thickness.
In the case of pleaters having compound surfaces, distances between thé plenums can be as much as 40 centimeters, A distance of 30 to 35 centimeters has most often been used~
, Best Mode and Industrial Applicability ~eb material which can be collapsed and tr~nsported by the devices of this inventlon includes ~ibrous material such as paper, metals ~uch as aluminum foil, synthetic polymcric mater~al such as polymer film and spunbonded polymer web~, and the like. The devices are particularly ~uited to collapsing and transporting webs of material having indefinite length. Nebs to be collapsed must only exhibit ~dequQte flexibility ~or trans-porting through the device.
; When it is desired to pleat a web and simultaneou~ly twist ~he web out of its inltial plRne3 pleaters having compound ~- 30 sur~aces are use~ul and 3uch pleaters are particularly useful when the web to be pleated and twi~ted i8 0~ a relatively thick material. Pleaters having compound surfaceq are ~lso particul-arly useful in collaps~ng ~ebs which Are not of uniform thick-~ ness or stiffne3s acroæ the web. Such webæ having e~p~cially thickened edges are more easily collapsed by a pleater having compound æur~aces because the co~pound surfaces cause the web , :
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edges ~o be buckle~ and twisted about ~he longltudinal axis of the web, As a specl:~ic example of th~ present inventlon mate:r~ al convergers having angle~ slot~ and ma~erlal guides can be u~ed 5 to rope webs of polyethylene t,erephthalate film as thick as about 125 microns (5 mils~, Polyethyl~ne terephthalate film as thick ~ about 5O microns (2 mils ~ can be roped and tran~ported using a material converger having angle~ s~o~s either w~;kh or without material guides or using a material converger havlng ~lots perpendicular to material transport and fitted with mat-erial guides.
A~ another speci~ic example of this lnvention, web pleaters having as few as one to a8 many as six or more plea*s can be used to collapse web~ o~ polyethylene terephthalate at least 350 microns (14 mils~ thick. While web pleater~ are useful for handling a wide range of materials; including films as thin as about ?5 mlCronB (l mil), the web pleater ~inds particular appllcation ~or pleating relatively heavy webs which are only difficultly collap~ed by other mean~, Ex~mples of such rel~
atively heavy webs would be polye~hylene terephthalate greater than Rbout 125 micron~ (5 mil~) thick and ~pun-bonded polypropyl-ene fabric about 116 g/m2 (3.5 ounces/yd2~ ln weight.
A preferred slot configuratlon for the devices lnvolves ~lots about 5 centimetcrs long spaced 5 centlmeter~ apart ~n the 25 direct~on of web travel wlth ~lot ends 5 centimeters apart ln the trans~erse direction. ~ouvers ~ormed from 810t8 in this configuration can have an opening about 0.15 centimeter wide.
The degree of web collaps~, expre~sed as a ratio o:f inltial web width to distance acros3 collapsed web c~n be from le98 than two to greater ~han ~even, Other`than ~ a matter of practicallty, there do not appear to be actual limit~ to the ratio, Wlth w~d0 webs ¢ollapsed over long dlstances or at ~harp angles, higher degrees of collapse can be obtaine~O For example, web~ as wide a5 about 3,75 meter~ can easily be pleated to less 35 ~han about 1 meter while being transported at more th~n 200 meters per minute; and webs ~s wîde as 8iX meter~ have b~en ea~ roped to le~ s th~n two m~ters while being transported at more than 500 me~æ p~r minute.

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2~t3 The number o~ pleats to which a web ~g subJected for collap~e i9 important only in~o~r as it i5 import~nt to reduce the height o~ the pleated webO ~or example, a web which has one pleat emerg~ from ~he web pleater with ~ heightequal to about one-half o~ the inltial web width while a web with four pleats will have a he~ ght o-f only about one-fourth of the initial web width, He~ght of the pleated web i9 important on occaslons wherein it is des~red to lntroduce pleated scrap webs directly into a shredding or chipping device to comminute the scrap 1nto an ePficient ~orm ~or recycling processes. In such a case, the pleated web mu~t be of a size to fit into the mouth o~ the shredder or chipper,

Claims (23)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pleating device comprising;
a first air feed plenum having an inlet end and an outlet end;
a transversely irregular surface on the first plenum, flat at the inlet end and progressing over the length of the surface to at least one peak at the outlet end a second air feed plenum having an inlet end and an outlet end;
a transversely irregular surface on the second plenum mating with the surface of the first plenum and juxtaposed in a spaced-apart relation thereto; and a multitude of slots with louvered openings in each irregular surface, said louvered openings directed toward the outlet ends.

2. A pleating device comprising:
a first air feed plenum having an inlet end and an outlet end;
a fan pleated surface on the first plenum, flat at the inlet end and progressing over the length of the surface to at least one peak at the outlet end;
a second air feed plenum having an inlet end and an outlet end;
a fan pleated surface on the second plenum mating with the surface of the first plenum and juxta-posed in spaced-apart relation thereto; and a multitude of slots with louvered openings in each fan pleated surface, said louvered openings directed toward the outlet ends.

3. The pleating device of Claims 1 or 2 wherein the distance along the plenum inlet end is about equal to the distance along the plenum outlet end.

4. The pleating device of Claims 1 or 2 wherein the plenum outlet ends have three peaks.

5. The pleating device of Claims 1 or 2 wherein the mating first and second plenum surfaces are between about 2 and 25 centimeters apart.

6. A web material waste handling apparatus comprising;
a wide web delivery means and a web pleating device operatively engaged with the wide web delivery means to receive and collapse wide web material comprising;
a first air feed plenum having an inlet end and an outlet end;
a transversely irregular surface on the first plenum, flat at the inlet end and progressing over the length of the surface to at least one peak at the outlet end a second air feed plenum having an inlet end and an outlet end;
a transversely irregular surface on the second plenum mating with the surface of the first plenum and juxtaposed in a spaced-apart relation thereto; and a multitude of slots with louvered openings in each irregular surface, said louvered openings directed toward the outlet ends.

7. A process for pleating a moving web of flexible material comprising;
holding the web under tension by applying longitudinal pneumatic force to a wide web of the material;
collapsing the wide web into a pleated struc-ture by applying transverse pleating forces to the web under tension over a predetermined length of the web;
and moving the web in the direction of the tension to continually apply longitudinal and transverse forces to the moving web, whereby the wide web is continually collapsed to a pleated structure.

8. A material converger comprising;
an air feed plenum having an inlet end and an outlet end;
a surface on the plenum decreasing in width from the inlet end to the outlet end;
a multitude of slots with louvered openings in the surface, said louvered openings being from 2 to 15 centimeters long, less than one-fourth the width of the surface, more than one-fourth and less than three louver lengths apart, and directed toward the outlet end; and means for applying transverse forces along the surface of the plenum to a web material transported in the converger to collapse the web material.

9. A material converger of Claim 8 wherein lateral edges of the surface are defined by material guides.

10. A material converger of Claim 8 wherein slots are arranged at an acute angle with a reference line from the center of the inlet end to the center of the outlet end.

11. A material converger of Claim 9 wherein slots are arranged at an acute angle with a reference line from the center of the inlet end to the center of the outlet end.

12. A material converger of Claim 8 wherein the slots are arranged perpendicular to a reference line from the center of the inlet end to the center of the outlet end.

13. A material converger of Claim 8 including a material feed plenum mounted on the air feed plenum and having the surface as a common wall between the air feed plenum and the material feed plenum.

14. A material converger of Claim 8 compris-ing a plurality of air feed plenums arranged such that the surfaces are juxtaposed in spaced-apart relation and the louvered openings are directed in concert.

15. A material converger of Claim 10 wherein the acute angle is from 40 to 60 degrees.

16. A material converger of Claim 11 wherein the acute angle is from 40 to 60 degrees.

17. A web material waste handling apparatus comprising;
a wide web delivery means;
a web material converger operatively engaged with the wide web delivery means to receive and collapse wide web material comprising;
an air feed plenum having an inlet end and an outlet end;
a surface on the plenum decreasing in width from the inlet end to the outlet end;
a multitude of slots with louvered openings in the surface, said louvered openings directed toward the outlet end;
means for applying transverse forces along the surface of the plenum to a web material transported in the converger to collapse the web material; and a comminuting means operatively engaged with the web material converger to receive collapsed web material.

18. A process for converging a moving web of flexible material comprising delivering a web to be converged to a material converger having an air feed plenum with an inlet end, an outlet end, a surface on the plenum decreasing in width from the inlet end to the outlet end, and a multi-tude of louvers in the surface directed toward the out-let end;

providing gas pressure to the air feed plenum sufficient to move gas through the plenum at a velocity greater than the web is moving to exert a longitudinal pneumatic force to the web to hold the web under tension;
applying balanced transverse forces toward the center of the web under tension over a predetermined length of the web to converge the web into a roped structure;
moving the web over the material converger in the direction of the tension to continually apply longi-tudinal and transverse forces to the moving web;
whereby the web is continually converged to a roped structure.

19. The pleating device of Claim 1 wherein the plenum outlet ends have a single peak.

20. The pleating device of Claim 19 wherein the single peak is round.

21. The pleating device of Claim 1 wherein the transversely irregular surfaces are curvillinear along their length.

22. The pleating device of Claim 21 wherein the plenum outlet ends have a single peak.

23. The pleating device of Claim 22 wherein the single peak is round.