CA1150046A

CA1150046A - Adhesive metering device

Info

Publication number: CA1150046A
Application number: CA000347427A
Authority: CA
Inventors: Stephen S. Flaum; Martin J. Leff
Original assignee: S&S Corrugated Paper Machinery Co Inc
Current assignee: S&S Corrugated Paper Machinery Co Inc
Priority date: 1979-03-20
Filing date: 1980-03-11
Publication date: 1983-07-19
Also published as: IT1131010B; JPS55127169A; JPS5829153B2; IT8020796A0; DE3007293A1; GB2113572B; GB2045115B; GB2113572A; GB2045115A; FR2451965A1

Abstract

ABSTRACT OF THE DISCLOSURE

A glue applicating means is constructed with an elongated shoe floatingly mounted alongside of and urged toward a glue applicator roll by a fluid controlled biasing means. A longitudinally extending depression in the shoe is substantially closed by the glue roll to define a glue cavity to which glue is fed by a positive displacement pump. The shoe is mounted so that the downstream end of the shoe is movable away from the glue roll automatically as required to permit glue to exit from the cavity at the same rate it is supplied thereto.
This provides what is effectively a self-adjusting nozzle or metering slot extending the full length of the shoe and through which glue is forced from the cavity to form a thin layer of uniform thickness on the outside of the glue roll.

Description

:~5S~046 ADHESIVE METERING DEVICE
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This invention relates ko fluid metering de-vices in general and in particular relates to means -Eor forming a glue film o~ controlled thickness on an applicator roll.
The hydrodynamics oE glue makes it difficult to predict glue behavior accurately. In U.S. P~ten*
No. 3,046,935 issued July 31, 1962 to 71.~Y. lYilson or a Gluing Control ~1eans, devices are disclosed for controlling glue ilm thic~ness on an applXcator roll as a function of machine speed and in this ~ay control the amount oE
glue applied by the applicator roll to a moving member.
E~-en though machine speed is of substantial significance - in connection with application-o-E Xnown quanti~ies of - glue, perhaps a more si~n1icant actor is glue viscosity~
That is, ~ith prior art constructions, glue film thickness on an applicator roll l~as subject to relati~ely ~ide uncontrolled variations because of changes in glue - viscosity brought on typically by reason of non-uniform glue quality and variation in glue temperature.
~o Another problem that arises ~ith prior art devices which utilize metering rolls results from the fact that different glue mixtures result in different speed curves for the metering. T~lese speed curves are difficult to determine and difficult to adjus-t.
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~.~50~46 In prior art devices having elongate~ glue rolls, mechanical impsrfections, such as run out of the roll, pr~vent accurate -formation of thin glue films. This last noted problem is bscoming increasingly signiicant bscause of new adhesivos which must bs applied in especially thin films.
In accordance with the instant invention adhesive met3ring means is provided to assure that a known quantity of adhesive is placed on the applicator roll over a -r~lativ31y wid~ range o-f machine speads and d~spite the fact that glue viscosity varies over a considerable ranga.
In addition, th~ device of ths instant invention is more readily kept running accurately despite practic~l probloms of manufacture and main$enance.
More particularly, in accordance with the instant invention an slongated sho3 is floatingly mountod alongsidio a glue applicator roll and is biased toward the roll. A glua cavity is formed through the coopsration of the outer surfac3 of tha a~plicator roll and a depression in tha s~oe. This cavity is always filled with glue and glu~ is delivered thereto by a po~itive displacemsnt pump.
The latter delivers a kno~n ~uantity oE glua over a relatively large rangs oE glue viscositiss. The glue pump delivers glue to the cavity at a pressure ~hich forces glue out of the cavity through a metsring slot along one edge theraof to form a glue ~ilm on th3 applicator roll.
Since the cavity is always fillod ~ith gluo, tho amount o~
glue d~oliv~r3d ~y the pump over a givsn time interval is nscessarily forced from tho cavity through the metering slot so that a ~nown quantity o~ glus is applied to the glue roll.
Accordingly, a primary object of ths instant inventioll is to provids a novel, improved device for met~ring adh~sivss and other fluidized materials.
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1 lS~U~ 4 6 An~ther objcct is to provide an adhesive metering device of this type wllich utilizes a positive displace~ent pump to deliver a known quantity o-f glue to a cavity whlch is partially bounded by the glue applicator roll.
- Still another object is to provide adhesive metering means o-E this type which is floating mounted alongside the glue applicator roll.
A further object is to provide adhesive metering means o~ this type which is construc~ed to assure that glue is applied e~enly to the entire glue applicator roll.
These objects as ~ell as other objects o~
this invention shall become readily apparent after reading the ~ollowing description of the accompanying dra~-ings in which:
Figure 1 is a fragmentary side elevation o~ a double backer including a glue control means constructed in accordance with teachings o~ the instant invention.
Figures 2 and 3 are ~ragmentary end vie-~s o~
the glue control means taken through the respective lines 2-2 and 3-3 o~ Figure 4 looXing in the direction of arro~s 2-2.
Pigure 4 is a side elevation of the glue - 25 control means shoe and mounting thereore looking in the direction o~ arro~s 4-4 o ~igure 3.
Figure 5 is an elevation lookin~ in the direction of arro~s 5-5 oE Figure 4 and sho~ing one of -the pivoted arms to ~hich the shoe o~ ~the glue control means is mounted.
No~ referring ~ore particularly *o Figure 1 ~hich illustrates portion 3]0 o~ a double bacXer which provides double faced board D b~ adding a second line L
to single faced board S. Single faced board S moves in the di~ection indicated by arro~ B around idler roll 311, partially ~raps-around preheater drum 312 and passes through the nip between pressure roll 31~ and glue applicator roll 101 where glue is applied to the ~L~5~346 free flute tips of single faced board S. Thereafter, the board S moves below deflector roll 317 into the nip between the lower flight of traction belt 319 and the.upstream or leftmost steam chest 318 t~here S liner L, moving in the direction of arrow C, joins single faced board S to form double face board n.
Upstream o, steam chests 318 liner L passes partly around rotating steam chest 316, partly around idler - - 315 and over support table .~2~. In a manner ~ell known to the art, board D ~asses over and is supported by a plurality of steam chests 31~ while being engaged from above hy moving traction belt 319 have a plurality of ~eight rolls 321 acting do-~n-~ard on the lo~er flight thereof to maintain board D in heat transferring relation-ships with steam chests 31S.
IYhen the corrugating process be;ng used does not recluire heating of liner L or heat:ing of single ~aced board S, prehea~ers 312 and 316 may he eliminated and/or replaced by low ~riction sllpports.
Similarly, preheaters 312, 316 ancl steam chests 318 may be deactivated by not being.heated. The latter may be re~laced by lo~ ricti.on s~lpports.
Aclhesive transer or glue roll 101 is an elongated cylinder fed with adhesive Erom pan ln4.
~letering means are provided for the application of ~: a uniform adhesive coatin~ on glue roll 101 by means .
. of control head 100 constructed in accordance with the instant invention and to be hereinafter described in detail. . - .
~.lue roll 101 and traction belt 31~ as well . ~-as other elements of the dou~le bac~er are synchronouslr driven from single variable speed main dri~re 401 by means o appropriate gearing and chains. That is, main drive 401 has one output that drives roller 10l. and .35 belt 319, indirectly through the l>elt and ~aper and another output ~hich supplies-the inp~lt to acljustable ratio coupler ~02. The outp2.2t o~ the latter is related 4~

to or synchron;.~cd ~Yith the in~ut to coupler ~n2 fllrnish by main drive 4~1, and drivcs pos;tivc displacement glue pump 405. Typically, the latter is a piston pump ~Yhich delivers a kno~Yn quantity (volume) of glue ~or a .
- 5 given pump s~eed even tho~gh glue viscosity changes .
over a relatively wide range and/or there are relatively large changes in hac~ pressure on the pump. Pump 405 - .
receives glue from pa~ ln4 and deli~ers glue t~rough flexible conduit 406 to control head 100.
No~Y referring.more particularly to Figures 2 through 5 ~or a detailed description o~ the glue meter ing means including control head lOn. In a manner well known to the art, the opposite ends of glue roll 101 . are of reduced diameter and are journalled in bearings tnot shown) mounted to fr~me section 98 which is ad-justably mounted on main frame 99 ~Fi~ure 1). These bearings are so positioned that glue roll lnl is rotated about its cylindrical ~xis lOS by main drive 4nl in a . direction indicated by arrol~ ~. Floatingly mo~lnted rearward and alon~side of glue roll 101 is elongated extruded shoe 10. Aligned rods 11 extend from o~posite ends of shoe 10 into bores 12 at the lo~Yer ends o arms 1~ who.se upper ends are providecl ~ith bores 16 ~hich . receive ali~ned stub-sha~ts 17. The latter extend into aligned apertures in adjustable frame section 98. In this manner shaft sections 17 pivotally mount arms 14 to frame sections 98, and shafts 11 pivotally mount shoe 10 to the ends of arms 14 opposite shafts 17. As ill hereinafter be seen, this permits shoe ln to move for~ard and rear-~ard with respect to frame member 98 on ~Yhich shoe.ln is mounted.
Aligned stuh sha~ts 18 at o~posite-ends of . . shoe 10 pivotally connect the latter to ~Year elements ~9 ~lhich ride on the outer surface 20 of glue roll 101 in slid;ng engagement therewith. Ho~Yever, shoe ln is free to pivot on the secondary axis de~;.ned hy ali~ned stub shafts 18. This secondary axis is parallel :to main axis 97 and glue cylin~ler axis lOS.

... _...... ~ -The forward Eace of s~o'e 10 is provided with depression 21 which partially defines glue cavity 22.
The latter is also bounded ~y a portion o glue Toll surface 20.' ~ive screws 24 at each end of shoe 10 secure plastic plates 23 and their backing plates 89 to opposite ends of shoe 10. Plates 23 define the end boundaries for glue cavit~r 22, and e~tend forward of shoe 10 -to par-tially overlap t~e ends o glue roll 101 in glue'sealing engagement therewith. Each of the three identical plastic splines 26, 27, 2S has an enlargement along one o its edges, that is captured within the respective longitudinal recesses 31, 32, 33 of shoe 10. Splines 26, 27, 28 are disposed upstream of cavity 22 with spline 26 providing the upstream edge seal between shoe 10 and glue roll surface'20. In the event spline 26 provides an imperfect seal against surEace 20~ spl;ne 27 ta~es over t~is seallng functio~l.
- 'l'he most upstream 28 of these three splines 26-28 has its free edge extending upstream into engagement with surace 20 to act as a scrapeT which removes glue -from portions of surface 20 beore they are opposite shoe depression 21. The glue removecl by scraper 28 falls into glue pan 104 which is connected through tube 96 to the intake of glue pump 405. Additional scraper or ',~ 25 other cleaner means ~not shown~ may be provided upstream ' `,~ o-f scraper 28.
- ` The downstream edge boundary for glue ca~ity , 22 is formed by blade 30 ~ihich is clamped to shoe 10 by , one leg of angle iTon 35. 'Clamping pressure is pro~ided ,- 30 by a'plurality of screws 36. The forward or -free edge of blade 30, is, as ~ill hereinafter be seen, biased toward engagement ~itIl glue roll sur~ace 20.
Oppositely extendlng legs 41, 41 o- elongated expandable bladder 40 are captured in complementary recesses o shoe 10 open at the rear t~ereof. Bladder 40 abuts one le~g of angle :iron 42 wIlose o-ther leg is secured by screws 43 to frame`section 98.

, . , , ' S]loe 10 is also provided ~ith longitudinal passage ~G ~hose opposite ends are sealed by plates 23.
Fittings ~7, 48, threadably mounted to shoe 10~ communi- -cate ~ith depression 21 and passage 46, respectively.
Flexible hose 406 extends from glue pump 405 to fi$ting 47. ~or a reason to be hereinafter explained, fitting ~8 may be connected to a source of temperature control-ling Eluid ~not shown) and/or hose 406 may be jacketed with a con~rolled temperature Eluid.
In operation, bladder 40 is illed ~ith air -or other fluid under pressure to provide a biasing force which urges shoe 10 for~ard to~!ard glue applicator roll 101. In the absence o other e~ternal forces acting on shoe 10, wear elements 19 and the free edge 51 of blade 30 will enga~e outer surface 20 o glue roll 101. Hol~ever, since cavity 2~ is filled with glue and additional glue ;s being introduced into cavity 22 by pump 405, there is an external force on shoe 10 resultin~ -from the pressurc generated by pump ~05 and this external force tends to moue shoe 10 rear~ard or to the left with respect to Pigure 3. The net torque acting on shoe 10 around pivot lS is counterclockl~ise.
Thak is, the torque ~xerted by pump ~05 on shoe 10 computed around pivot lS exceeds the torque exerted by the ~luid pressure in bladder 40 on shoe 10 around the same pivot 18, so that the net value o these torques tends to rotate shoe 10 rearward. Bladder 40 is posi-tioned to exert more force on ~ear elements 19 than on blade 30~ and cavity 22 is located closer to blade 30 than to l~ear elements 19, so that shoe 10 tends to pivot counterclock-~ise and ~ear element 19 stays in - contact ~ith cylinde~ surEace 20. This causes shoe 10 to pi~ot slightly about its secondary axis lS. The pivoted mounting arms 14 for shoe lb permit the loca-tion of ma;n axis 97 to shift as required to accommodate pivotal motion o~ shoe 10 about secondar~ pivot 1~.
The net eEect oE this pivotine motion Eor shoe 10 is .

~,o scpa~atç t}~e :Eree end Sl o bl~de 30 from outer surface 2~ o:E glue roll 101 to ~orm a narrow m~tering slot throug]l ~hich glue escapes from cavity 22 and deposits itself as a layer of controlled thickness on the portion of moving sur;Eace 20 do~lstream of blade 30.
It should no-~ be o~vious to those skilled in ' the art that the quantity o~ glue ~eing forced from ' cavity 22 through the metering slot at free edge 51 o 10 blade 30 is equal to the amount o glue being delivered by posi*ive displacement pump 405. The width of this metering slot adjusts itself automatically to accommodate , the quantity of'glue being delivered to cavity 22.
That is, during a given time interval, if the quantity Of glue being delivered ~y pù~lp 405 increases, the same ~uantity must be forced from cavity 22 through the metering slot. If the metering slot were to remain at the same width, the pressure ~it~lin cavity 22 ~ould increase and thereby urge shoe 10 to pivot count,ercloc~-wise. Howe~er, to prevent pressure ~uildup in cavity22, the metering slot at free end 51 of blade 30 automatically ,increases in ~idth to permit an increased flow rate for the glue leav.ing cavity 22.
' l~hen precise control of the temperature for.
25 glue ~ithin cavity.22 is required, liquid of controlled temperature (either hot or cold) is circulated through passage 46.' This liquid is introduced through fitting ' -' 48. It is noted that even though only one fitting 48 : is shown connected t~ passage ~6, t~ere is a~ least.one , additional fitting 4S mounted to s~oe 10 and connected to passa~e 46. ~urther, e~en though one fitting 47 i5 sho~n communicating ~lith glue cavity 2Z there may.be a ' . plurality of ~ittings 47 spaced along the lengtll.of shoe 10 for i,ntroduction o:E glue'into cavity 22 at a - ' plurality oE loca-tions along the length thereo~.
It should now be apparent to those s~illed in the art that relatively flexi~le sealing splines 26, 27 ~,54)046 may be replaced by more rigid sealing strips ~no~ .
sho~n) and spring elements which act between shoe means 10 and these sealing strips to bias the latter into sealing engagement with cylindrical surface 20. .
Wear elements l9 may be extended across the en~ire length of shoe means 10 and may also serve as a seal ~ hile the instan~ invention has been described in connection with metering of glue, it is noted the teachings of the instant invention may be utilized for metering in flexo inX systems. It is also noted : that by removing pressure from the inside of bladder 40, the fluid metering gap be*ween cylindrical surface 20 and free edge 51 of blade 30 may be opened sufficiently for entry into cavity 22 for cleaning thereof. . .
lS Although.the present invention has been .
described in connection ~ith a preEerred embodiment thereof, many variations and modi~ications will no~
become apparen* to those skilled in the art, It is : preferred, therefore, that t~he present invention be limited not by the speci~ic disc].osure herein, but only by the appended claims.
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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Fluid metering means including a fluid carrying cylinder for applying a fluid film to a workpiece element moving relative to said cylinder; said fluid carrying cylinder being mounted for rotation on its relatively stationary cylindrical axis; shoe means extending parallel to said cylindrical axis; said fluid carrying cylinder having an outer cylindrical surface and said shoe means having a side confronting a portion of said cylindrical surface; a fluid cavity extending generally parallel to said cylindrical axis; said fluid cavity being formed by a depression in said side of said shoe means and being partially bounded by a portion of said cylindrical surface; first means engaging said cylindrical surface while said cylinder rotates and sealing said fluid cavity along its upstream edge;
a fluid distribution slot partially bounded by said cylindrical surface and positioned along the downstream edge of said fluid cavity; said slot providing the sole opening through which fluid exits from said cavity;
means movably mounting said shoe means to permit said fluid distribution slot to vary in thickness; biasing means urging said fluid distribution slot to close; a supply of essentially incompressible fluid; delivery means to deliver fluid under pressure from said supply to said fluid cavity at a known rate which is substantially independent of pressure in said fluid cavity and thereby create pressure within said fluid cavity urging said fluid distribution slot to open; said shoe means assuming an equilibrium position, under the control of opposing forces generated by said biasing means and said delivery means, whereby fluid is forced from said cavity through said slot to form a controlled fluid film on said cylindrical surface of said fluid carrying cylinder with said fluid film, without doctoring, being of a character suitable for application in final usable form directly to a workpiece element; and means acting independently of fluid viscosity and pressure variations over substantial ranges to synchronize operation of said delivery means with rotational speed of said fluid carrying cylinder; said delivery means maintaining said fluid cavity filled with fluid whereby, independently of fluid viscosity and rotational speed variations over substantial ranges, fluid is forced from said cavity through said slot at a rate equal to the rate at which said pump means delivers fluid to said cavity.

2. Fluid metering means as set forth in Claim 1 in which the fluid distribution slot is elongated, relatively narrow and of uniform thickness throughout the length thereof.

3. Fluid metering means as set forth in claim 1 in which the biasing means urging said fluid distribution slot to close is fluid operated.

4. Fluid metering means as set forth in Claim 1 in which the shoe means is in operative mechanical engagement with the cylindrical surface so that said shoe means will move radially under control of the cylindrical surface pursuant to cylindrical imperfection in said cylindrical surface and/or if the latter rotates about an axis displaced from the axis about which the cylinclrical surface is formed.

5. Fluid metering means as set forth in Claim 4 in which the means floatingly mounting said shoe means includes arm means having first and second spaced parallel pivots extending generally parallel to the cylindrical axis; relatively stationary frame means to which said arm means is connected at said first pivot; said shoe means being connected to said arm means at said second pivot; said shoe means remaining in operative mechanical engagement with the cylindrical surface as said shoe means pivots about a third pivot to vary the width of of the fluid metering slot; said arm means and said pivots being proportioned and operatively connected for enabling the shoe means to be pivoted away from the cylindrical surface sufficiently to permit access to said fiuid cavity through said fluid metering slot, by enlarging the latter, for cleaning of said fluid cavity.

6. Fluid metering means as set forth in Claim 1 in which the portion of the glue cavity midway between the upstream and downstream edges of said glue cavity, as measured at the cylindrical surface, is downstream of the point at which the force vector exerted by the biasing means intersects the cylindrical surface.

7. Fluid metering means as set forth in Claim 1 also including scraper means disposed upstream of said first means and downstream of the location on said cylinder where a fluid film is applied to a workpiece element, said scraper means being in engagement with the cylindrical surface to remove fluid therefrom prior to application of fluid thereto at said fluid distribution slot.

8. Fluid metering means as set forth in Claim 7 in which the first means includes a spline secured to said shoe means, said spline extending downstream and toward said cylindrical surface and being generally parallel to the cylindrical axis.

9. Fluid metering means as set forth in Claim 7 in which the first means and the scraper means include respective first and second splines secured to said shoe means, said splines extending toward said cylindrical surface and being generally parallel to the cylindrical axis.

10. Fluid metering means as set forth in Claim 9 in which the first and second splines extend downstream and upstream, respectively, from their respective areas of engagement with said shoe means.

11. Fluid metering means as set forth in Claim 1 in which the fluid in said fluid cavity is an adhesive.

12. Fluid metering means as set forth in Claim 1 in which the first means includes an elongated sealing element and resilient means biasing an edge of said sealing element into fluid sealing engagement with said cylindrical surfaces.

13. Fluid metering means as set forth in Claim 1 in which the delivery means comprises a positive displacement device.

14. Fluid metering means as set forth in Claim 1 in which the first means includes an elongated sealing element and resilient means biasing an edge of said sealing element into fluid sealing engagement with said cylindrical surfaces.

15. Fluid metering means as set forth in Claim 1 also including sealing means secured to said shoe means closing the ends of the cavity and partially overlapping opposite ends of the cylinder.

16. Fluid metering means as set forth in Claims 2, 3, 7, 8, 9, 11, 12 or 15 in which the delivery means comprises a positive displacement device.

17. Fluid metering means as set forth in Claims 1, 11 or 13 in which the slot is located at the highest point of said cavity.

18. A method for manufacturing corrugated board comprising the steps of pumping adhesive into a cavity partially bounded by a rotating adhesive roll, said cavity having a transverse fluid distribution slot along its downstream edge, said cavity being formed in a floating shoe that extends parallel to the rotational axis of the adhesive roll and is biased toward said shoe with a force less than that force transmitted through adhesive in the cavity and urging the fluid distribution slot to enlarge, said adhesive being delivered to said cavity at a known rate and moving through the fluid distribution slot at a rate equal to the rate at which adhesive is delivered to said cavity to form an adhesive film on the periphery of the adhesive roll, forming transverse corrugations in a longitudinally moving web of paper and applying adhesive to the tips of the corrugation by bringing them into contact with said adhesive film, and thereafter applying a liner web to those tips to which said adhesive has been applied.

19. A method for manufacturing corrugated board as set forth in Claim 18 in which the adhesive film as it is applied to the tips of the corrugations is of essentially the same thickness as when the adhesive film is adjacent the metering slot on the downstream side thereof.

20. A method for manufacturing corrugated board as set forth in Claims 18 or 19 in which the rate at which adhesive is fed to said cavity is sufficient to maintain said cavity full and force adhesive through the metering slot.