GB2190607A

GB2190607A - Applying flowable materials to running webs of paper and the like

Info

Publication number: GB2190607A
Application number: GB08710275A
Authority: GB
Inventors: Erich Pagendarm
Original assignee: Will E C H; ECH Will GmbH and Co
Current assignee: Will E C H; ECH Will GmbH and Co
Priority date: 1986-04-30
Filing date: 1987-04-30
Publication date: 1987-11-25
Anticipated expiration: 2007-04-30
Also published as: GB2190607B; FR2598102A1; FR2598102B1; CH676805A5; NL8701020A; GB8710275D0

Description

GB 2 190 607 A 1

SPECIFICATION the second stream.

The method preferably includesthe step of estab Method and apparatus for applying flowable mate- lishing alongthe second portion of the second path an rialsto running webs of paper andthe like open-ended channel one end of which receives successive increments of the remaining portion of the The invention relates to a method of and toan first stream and the other end of which receives apparatus for applying flowable materials, such as successive increments of the second stream. The adhesive paste, to running webs of paper or the like. conveying step can include pumping the material of More particularly, the invention relatesto improve- the second stream into the channel, particularly by ments in methods and apparatus of the type wherein a 75 maintaining the material of the supply at an elevated conveyor is used to draw a stream of flowable material pressure.

from a supply and to transfer successive increments The conveyor is preferably utilized as a means for ofthe withdrawn stream to successive increments of drawing the first stream from the supply, and the step the running web. Apparatus of such character are of establishing the channel can: include using the often used in tobacco processing (filtertipping, 80 conveyor (particularlythe peripheral surface of the cigarette making, filter rod making and cigarette aforementioned embossing cylinder) as part of the packing) machines wherein tobacco and/orfilter boundaryforthe channel.

material is draped into a continuous web or into The conveying step can include entraining at least a sections of a subdivided web. part of the remaining portion of the first stream with It is already known to construct adhesive applying 85 the second stream, and such method can further and like apparatus in such a waythatthe conveyor comprise the step of pumping the second stream and which draws a stream of flowable material (particular- the entrained part of the remaining portion of the first ly in a viscous substance) from a source of supply stream backto the supply. As mentioned above, the returnsthe non-applied portion of the stream to the method can further comprisethe step of pressurizing source. Such procedure is not entirely satisfactory 90 the material of the supply, and the conveying step because bubbles of entrapped air andlor other then includes admitting pressurized material from the gaseous fluids prevent a fully predictable coating of supply into the other end of the channel. Such method the web and are especially undesirable if the web is to can also include the step of reducing the pressure of be provided with a pattern of patches of flowable viscous material in the channel, preferably down to or material ratherthan with a continuous uninterrupted 95 nearly down to atmospheric pressure. The conveying layer. Moreover, heretofore known apparatus do not step can include advancing the material of the second always ensure desirable thorough mixing of returned stream and a part at least of the material of the flowable material with freshly admitted flowable remaining portion of thefirststream through at least material. one additional channel and on to the supply of viscous One feature of the present invention resides in the 100 material so thatthe second stream advancesthrough provision of a method of applying a coat of viscous a series of channels before it returns into the supply.

material, such as polyvinyl acetate glue, to a running Anotherfeature of the invention resides in the web of paper orthe like (e.g., to a running web of provision of an apparatus forapplying a continuous or tipping paperwhich is used to unite plain cigarettes interrupted coat of viscous material to a running web with filter mouthpieces in filtertipping machines). The 105 of paper orthe like. The apparatus comprises means method comprises the steps of transporting the web for transporting the web along a first path, a source of along a first path, establishing and maintaining a supply of pressurized viscous material, conveyor supply of viscous material at a location remote from means for advancing a first stream of viscous material the first path, advancing from the supply a continuous in a predetermined direction from the source along an first stream of viscous material in a predetermined 110 endless second path a predetermined portion of direction along a preferably endless second path which is adjaceritthe first path so that a first portion of having a first portion adjacent a portion of thefirst the stream is transferred onto the web and the path and a second portion upstream of the supply of remaining portion of the stream is advanced toward viscous material and downstream of the first portion, the source, and means defining a channel adjacent a transferring a portion of the stream onto the web in 115 second portion of the second path and also adjacent thefirst portion of the second path so thatthe the source so that a second stream of viscous material remaining portion of the stream advances toward and flows from the source into thechannel counterto the along the second portion of the second path, and predetermined direction to intimately contactthe conveying a second stream of viscous material along remaining portion of the firststream.

the second portion of the second path counterto the 120 The channel defining means preferably includes a predetermined direction so as to establish intimate portion of the conveyor means. The conveyor means shearing contact between the remaining portion of the can include a substantially cylindrical member (such first stream and the second stream, as an embossing cylinder) having a peripheral surface The advancingstep preferably includes advancing which drawsthefirst stream from the source and the firststream by a driven conveyor (e.g., an 125 bounds a portion of the channel.

embossing cylinder) which defines the second path, The apparatus can f u rther comprise means for and the conveying step preferably includes effecting a equalizing the f irst stream on the peripheral surface of flow of material of the second stream from the supply the cylindrical member between the sou rce and the along the conveyor so thatthe remaining portion of predetermined portion of the second path. The the first stream is located between the conveyor and 130 apparatus can also comprise means for sealing the 2 GB 2 190 607 A 2 source inthe region of the equalizing means.The small supplyof pressurized viscous material adjacent lattercan comprise a rotorhaving a peripheral surface a portion of the endless path which is defined bythe which equalizesthe firststream on the conveyor, and peripheral surface 13 of a conveyor 7 in theform of an the sealing means can comprise an elastic doctor embossing cylinder rotating about an axis which is which engages the peripheral surface of the rotor. 70 parallel to the axis of the roller 18. The non-referenced The source normally contains a viscous material shaft drives the cylinder7 in the direction which is with bubbles of entrapped gaseous fluid. The channel indicated by arrow 6 so thatthe peripheral surface 13 defining means preferably includes or defines an receives a stream of viscous material in the region of expansion zone forthe gaseous fluid in the viscous the chamber4 and is relieved of a portion of such material passing through the channel. At least one 75 stream as a result of travel along that (predetermined) second channel can be defined between the source portion A of the endless path which is adjacentthe and the expansion zone, and a partition (e.g., a roller 18.

squeegee or doctorwhich engages the conveyor The reference character 8 denotes a squeegee (e.g., means) can be provided between the channels. a flexible doctor blade) which is mounted in the As mentioned above, the apparatus of the present 80 housing 5 defining the chamber 4 and acts not unlike a invention can be used in a filtertipping machine surplus removing equalizing device which ensures wherein the running web is a strip of tipping paper and that successive increments of the peripheral surface the source of supply is a tank or another suitable 13 of the cylinder 7 entrain predetermined quantities vessel for a body of adhesive, such as polyvinyl of viscous material toward the roller 18. The squeegee acetate glue. 85 8 is preferably at least slightly elastic and it performs The novel features which are considered as charac- the additional function of sealing the chamber 4 in the teristic of the invention are setforth in particular in the region where its edge cooperates with the peripheral appended claims. The improved apparatus itself, surface 13 of the cylinder7.

however, both asto its construction and its mode of As a rule,the material in the chamber4 contains at operation, together with additional features and 90 leastsome minute bubbles of airand/or another gas advantages thereofwill be best understood upon which aretransported in the stream along the perusal of thefollowing detailed description of certain peripheral surface 13 of the cylinder7. The remaining specific embodiments with referenceto the accom- portion of the stream (i. e., that viscous material which panying drawing. is returned from the roller 18toward the chamber4), FIG. 1 is a schematic partly elevational and partly 95 carriesthe entrapped bubbles of airand, in the vertical sectional view of an apparatuswhich embo- absence of any undertakingsto the contrary,would dies one form of the invention; reintroduce the bubbles into the mass of viscous FIG. 2 is a similar schematic partly elevational a nd material in the chamber 4. This would rapidly enrich partly vertical sectional view of a modified apparatus; the viscous material with gaseousfluid so that a FIG. 3 is an elevational view of an em bossing 100 relatively large quantity of gaseous f 1 uid in the stream cylinderwhich can be used in the apparatus of FIG. 1 atthe periphery of the cylinder7would unduly or2; interfere with predictable application of a coat of such FIG. 4 is an enlarged fragmentary axial sectional material to the respective side of the running web 1.

view of the embossing cylinder as seen in the direction The apparatus of FIG. 1 is designed with a viewto of arrowsfrom the line W-W in FIG. 3; 105 prevent reintroduction of bubbles of air orother gases

FIG. 5 is an elevational view of a modified embos- into the chamberMor renewed transport by the sing cylinder; peripheral surface 13 of the cylinder7. In addition,the FIG. 6 is an enlarged fragmentary axial sectional apparatus is constructed and assembled in such a way view as seen in the direction of arrows from the line that it ensures a thorough mixing of viscous material VIM of FIG. 5; and 110 which constitutes the aforementioned remaining FIG. 7 is a fragmentary axial sectional view similarto (non-applied) portion of the stream which is drawn by that of FIG. 4 and further showing means for sealing the cylinder7 with fresh material which is supplied by one axial end of the embossing cylinder. the pump 2 via conduit 3. This is accomplished in that Referring firstto FIG. 1, there is shown an apparatus the apparatus defines an elongated channel 11 which wherein an elongated web 1 is transported along an 115 is defined by a baffle or hood 14forming part of or elongated path by a transporting system including affixed to the housing 5 of the chamber4 in rollers or analogous conveying elements one of which conjunction with that portion of the peripheral surface is shown at 18. The web 1 is transported in the 13 of the cylinder7 which is located immediateoy or direction which is indicated by arrows and it can closely upstream of the chamber4. That portion of the consist of or contain paper, cardboard, synthetic 120 channel 11 which is more distantfrom the chamber4 plastic material, textile material (including woven or is enlarged to constitute an expansion chamber 12 for non-woven fibers) andlor others. The apparatus viscous material which forms a continuous (second) serves to provide one side of the running web 1 with a stream flowing from the chamber 4 into the respective layer or coat of flowable material, especially a end of the channel 11 to intimately contactthat flowable viscous material which contains at least one 125 (remaining) portion of the first stream which is liquid ingredient and is to be applied in a highly transported bythe cylinder7 from the transfer station predictable manner. A source of such flowable vis- (at A) between the roller 18 and cylinder 7 backtoward cous material includes a pump 2 which draws material the chamber 4. The remaining portion of the first from a magazine 17 and conveys it by way of a conduit stream entersthe other end of the channel 11 and is 3 into a plenum chamber 4 which contains a relatively 130 relieved of some or all entrapped air bubbles (particu- 3 GB 2 190 607 A 3 larly microfoam) as a resultof intimate contact with viscous material in the chamber4 is desirable and the second stream of viscous material flowing counter advantageous because it enables an operatorto to the direction which is indicated bythe arrow 6 due conform the respective parameters to the consistency to elevated pressure which prevails in the plenum of the mass in the magazine 17, especiallyto the chamber4 underthe action of the pump 2. The second 70 viscosity of such mass. This, in turn, ensures the stream which flows in the narrow portion of the establishment of an optimum shearing action be channel 11 immediately adjacent the chamber4 tween returning viscous material and the second entrainsthe bubbles into the expansion chamber 12 stream of viscous material in the channel 11 and its where the bubbles leave the viscous material and expansion chamber 12. The conduits 3 and 16 can be escape into the atmosphere. The second stream also 75 said to constitute additional channels through which entrains at least some material of the remaining the material must pass on its wayfrom the peripheral portion of thefirst stream which advancestoward the surface 13 of the cylinder7 back into the chamber 4.

narrower portion of the channel 11 in the direction of The reference character38 denotes that portion of the arrow 6 so thatthe expansion chamber 12 receives at path forthe flow of viscous material from the chamber least a certain percentage of the material which has 80 4to the magazine 17 and backto the chamber 4where already advanced towards the station atA but was not the pressure of viscous material is, or at least applied to the adjacent side of the running web 1. Te approximates, atmospheric pressure.

second stream is likelyto remove and entrain at least The material in the chamber4 is Hkelyto contain someviscous material in that layerof the remaining bubbles of entrapped gases, particularly air, if the portion of thefirst stream which is exposed, i.e.,which 85 viscosity of the material is rather high. Expulsion of is located ata maximum distancefrom the peripheral such bubblesfrom the material which is aboutto form surface 13 of the cylinder7. thefirststream is desirable and advantageous be Theshearing action of the second stream which cause itcontributes significantlyto predictability of flows into the channel 4 dueto pressurization of the pattern of viscous material which is applied tothe viscous material in the chamber4 is especially 90 running web. This holdstrue regardless of whether desirable when the cylinder7 is an embossed cylinder the web is provided with a continuous coat of viscous having hatchings (recesses andlor grooves) of the material orwith a pattern of squares, rectangles, type shown in FIGS. 4to 7 andlor otherforms of helices andlorother configurations. Verysmall bub depressions, protruberances and the like. bles of air and/or other gaseousfluid are known as The configuration of the surfaces (including a 95 microfoam; such small bubbles can be effectively portion of the peripheral surface 13) surrounding the expelled in the expansion chamber 12, especially if the expansion chamber 12 of the channel 11 is preferably expansion chamber is designed to causethe develop such thatthese surfaces allowforthe development of ment of eddy currents which contribute to an accu a pronounced eddy (indicated by arrow 15). As shown, mulation of smaller bubbles into larger bodies of the surfaces surrounding the expansion chamber 12 100 entrapped gases which thereupon rise due to buoyan preferably conform to the anticipated configuration of cy and are permitted to escapefrom the chamber 12 the eddy 15. Such configuration is desirable and ratherthan to enterthe conduit 16.

advantageous because minute bubbles of airwhich FIG. 2 shows a modified apparatus wherein the enterthe expansion chamber 12from the one orthe means for equalizing the stream of viscous material otherend of the channel 11 are caused to advance 105 on the peripheral surface 113 of the embossing along the path which is defined bythe eddyto gather cylinder 107 comprises a roller 121 (hereinafter called into larger bubbleswhose buoyancy sufficesto rotor) which is driven countertothe direction (arrow ensurethatthey rise and escape atthetop of the 106) of rotation of the cylinder 107Another difference chamber 12 between the peripheral surface 13 of the between the apparatus of FIGS. 1 and 2 is thatthe cylinder7 and the adjacent upper edge face of the 110 apparatus of FIG. 2 comprises means defining a hood 14. The inclination of the inner side of the hood second channel 126 which allows for a multi-stage 14 atthe top of the expansion chamber 12 is preferably reduction of the pressure of viscous material on its selected in such a waythat it promotes the propagawayfrom the plenum chamber 104toward the tion of largerair bubblestoward the upper inlet of the expansion chamber 112, i.e., toward the enlarged channel 11 and thence intothe atmosphere. 115 portion of the channel 111 fortheflow of a second The housing 5 forthe chamber4 has an outletwhich stream of viscous material from the chamber 104 is the inlet of a conduit 16 serving to conveythe counterto the direction of rotation of the cylinder 107.

intermixed remaining portion of the first stream and All such parts of the second apparatus which are the second stream from the expansion chamber 12 identical with or clearlu analogous to the correspond into the magazine 17 wherein the material which is 120 ing parts of the apparatus of FIG. 1 are denoted by discharged bythe conduit 16 is mixed with thefresh similar reference characters plus 100.

viscous material priorto entering the pump 2 for The squeegee 108 is a scraper or doctor which admission into the plenum chamber 4via conduit 3. removes viscous material from the periphery of the The width of the channel 11 is preferably adjustable equalizing rotor 121 and compels such material to in a mannerwhich is not specifically shown in the 125 remain in the chamber 104. The free edge of this drawing (e.g., by moving the hood 14 relative to the squeegee is immediately or closely adjacentthe nip housing 5 forthe chamber4). The pressure of viscous 129 of the cylinder 107 and equalizing rotor 121. The material which leaves the pump 2, to enterthe conduit material which is drawn bythe pump 102 from the 3 and chamber 4, is also adjustable. Such adjustability magazine 117 passes through the conduit 103 on its ofthewidths ofthe channel 1 land of the pressure of 130 way into an auxiliary chamber 122 to flow along the 4 GB 2 190 607 A 4 convexside ofthe baffle orhood 114and intothe analogous to that of the apparatuswhich isshown in lowerportion ofthe chamber 104where itis contacted FIG. 1.Thus,the equalizing rotor 121 ensuresthat bysuccessive incrementsof the peripheral surface successive increments of the peripheral surface 113 of 113 of the driven cylinder 107 sothatthe latter the cylinder 107 entrain identical or practically identic transports a first stream (indicated by a heavy line) 70 al quantities of viscous material from the chamber 104 from the nip 129 toward thetransfer station atA where whereby such viscous material passes throughthe nip the cylinder 107 transfers a portion of the equalized 129 and a portion thereof is applied to the underside of first stream onto the underside of the running web 101 the running web 101 at the transfer station A. The which is guided by a roller 123. The roller 123 is driven remaining portion of the stream is returned towardthe to rotate in a clockwise direction. The housing 105 for 75 chamber 104 and is removed from the peripheral the chamber 104 has one or more passages which surface 113 bythe squeegee 127. The removal viscou:T connectthe chamber 122 with the chamber 104 and material remains in the expansion chamber 112.

thus permitfresh viscous material (which was admit- Remnants of viscous material (especially in the ted via conduit 103) to enterthe chamber 104 adjacent grooves of the peripheral surface 113) advance the tip of the squeegee 108. 80 beyond the squeegee 127 and are met by the second The remaining portion of the stream on the stream which flows in the channel 111 toward the peripheral surface 113 of the cylinder 107 is transchamber 124. The second stream f lows at a rather high ported backtoward the location (E) of the expansion speed which is determined bythe pressure in the chamber 112 which also receives a second stream of chamber 104, and the shearing forces which develop viscous material flowing from the chamber 104, 85 in the channel 111 ensure that at least some remnants through the narrow portion of the channel 111 and of the first stream are compelled to enter the chamber toward the conduit 116 which conveys the mixture of 124 ratherthan returning into the chamber 104. The returned material and second stream into the maga- pressure in the chamber 124 is less than in the zine 117. The second stream removes microfoam from chamber 104 but exceeds the pressure in the expan the remaining portion of thefirst stream, and the 90 sion chamber 112 (wherein the pressure matches or bubbles which gather in the expansion chamber 112 can equal or approximate atmospheric pressure). The are freeto rise and escape (at 138) from the apparatus material which leaves the expansion chamber 112 to ratherthan entering the conduit 116 for admission into enterthe conduit 116 is at least substantially devoid of the magazine 117. any entrapped gas bubbles. The manner in which the In orderto further enhance the mixing of returned 95 chamber 112 is designed to promote the formation of viscous material with the material of the second one or more eddy currents of viscous material and to stream, the housing 105 of the apparatus of FIG. 2 thusfaciliate the accumulation of smaller bubbles into defines an additional chamber 124which receives larger bubbles which rise due to buoyancy and leave viscous material from the narrow portion of the the expansion chamber 112 at 138 ratherthan entering channel 111 (atthe right-hand end ofthe hood 114) 100 the conduit 116 is orcan bethe same as described in and admitsviscous material intothe second channel connection with FIG. 1.

126which leads into the expansion chamber 112. A It has been found thattheviscous material which partition intheform of an elastic squeegee 127 (e.g., a fillsthe chamber 104 is at least substantially devoid of doctor) is mounted in a block of the housing 105forthe entrapped gases so that it can properlyfill the grooves chambers 104,122,124 and cooperateswith the 105 or like recesses in the peripheral surface 113 of the peripheral surface 113 of the cylinder 107 to prevent cylinder 107, Le., the latter can entrain predictable directflowof viscous material from the narrow quantities of viscous material toward thetransfer portion of the channel 111 intothe expansion chamber station Aforapplication to successive increments of 112. It can be said thatthe channels 111, 126 constitute the running web 101. The metering action of the two sections of a composite channel which serves to 110 equalizing means 121 also contributes to predictable conveythe second stream from the chamber 104 into application of viscous material to the web 101.

the expansion chamber 112. Any material of the first An important advantage of the improved apparatus stream which happens to advance beyond the edge at is that it ensures predictable application of viscous the upper end of the squeegee 127 is contacted bythe material to the running web 1 or 101 as well as the second stream which removes bubbles of gaseous 115 application of viscous material which is at least fluid, at leastfrom the exposed side of the returning substantially free of entrapped gaseous---fluids.

material of the first stream, and causes such bubbles Moreover, the apparatus ensures a highly satisfactory to enterthe chamber 124 on their way into the channel regeneration of viscous material, i.e., a thorough 126 and thence into the expansion chamber 112. The intermixing of returned viscous material with material squeegee 127 more or less completely sealsthe 120 which is drawn from the magazine 17 or 117. Still expansion chamber 1 12from the chamber 124 along further,the apparatus ensures highly satisfactory the peripheral surface 113 of the cylinder 107 sothat removal of returned viscous material from the the chambers 112,124 can communicate only or peripheral surface of the cylinder7 or 107; this almost exclusively by way of the channel 126. includes viscous material which fills the grooves or The pump 102 ensures thatthe viscous material in 125 like recesses in the peripheral surface 13 or 113.

the chamber 104 is maintained at an elevated pressure The utilization of a pump which ensuresthatthe which sufficesto guarantee the flow of a second pressure in the chamber 104 is above atmospheric stream into the channel 111 counterto the direction of pressure is desirable and advantageous, especially if rotation of the cylinder 107. the cylinder7 or 107 isto be driven at an elevated The mode of operation of the apparatus of FIG. 2 is 130 speed. This will be appreciated by bearing in mind thal GB 2 190 607 A 5 changes inthe peripheral speed of the cylinderentail a The apparatus of the present invention can be used quadratic (square) rise of pressure of viscous material with advantage in a numberof machines or produc in the chamber4 or in the chambers 104and 128.The tion lines. For example, the apparatus can beused in a width ofthenip 129isdetermined bythepressure filtertipping machinewherein plain cigarettes, cigars differential between the interior of the chamber 122 70 orcigarillosof unitlength or multiple unit length are and O. Ifthewidth ofthenip 129 is constant, the rate joined end-to-end with filter mouthpieces of unit of flow of viscous material is linearly dependent upon length or multiple unit length. The viscous material is such pressure differential. Moreover, the rate of flow then an adhesive (such as polyvinyl acetate glue with is dependent upon the characteristics of the materials a watercontent of approximately 50 percent) which is of the cylinder 107 and rotor 121, namely on the ability 75 applied to a running web of so-called tipping paper.

of the parts 107 and 121 to retain and attractthe The utilization of the improved apparatus is especially viscous material. The materials of the rotor 121 and desirable and advantageous if the web is to be cylinder 107 can be readily selected in such a waythat provided with a pattern of glue ratherthan with a thethickness of thefirststrearn which leavesthe single continuous layer. This is often desirable in chamber 104with the peripheral surface 113 is at least 80 tipping machines, e.g., in those known as MAX and substantially constant without altering the peripheral MAX S which are manufactured and distributed by speed of the rotor. This applies especiallyfor higher Hauni-Werke K6rber &CO. KG. Hamburg, German rotational speeds of the cylinder 107. If the rotational Federal Republic. These machines convert plain speeds of the rotor 121 is close to zero, the thickness of cigarettes and filter mouthpieces into a filter the first stream on the peripheral surface 113 of the 85 cigarettes by using an adhesive-coated web of tipping cylinder 107 is likelyto fluctuate butthis can be readily paperwhich is subdivided into sections called uniting compensatedfor by altering the speed of the pump band, and the unitingbands arethen convoluted 102. around the abutting ends of plain cigarettes and filter The apparatus of FIG. 2 will be utilized if it is mouthpieces. Reference may be had to U.S. Pat. No.

necessaryto maintain the viscous material in the 90 4,249,547 granted February 10, 1981 to Alfred Hinz chamber 104 atan elevated pressure. It isthen mann. The filter tipping machine of Hinzmann can advisableto reducethe pressure of the second stream employthe apparatus of the present invention. Of in several stages, i.e., first on itswayfrom thechamber course, the pattern of adhesive pastewhich is applied 104intothe chamber 124, and thereupon on its way bythe cylinder7 or 107 can be selected practically at from the chamber 124 intothe expansion chamber 95 will and can deviate considerably from those shown 112. The number of stages can be increased to three or nd described in the patentto Hinzmann andlorfrom even more. those shown in FIGS. 3-6 of the present application.

FIGS. 3 and 4 shows a so-called embossing cylinder For example, the longitudinally extending uncoated which can be used in the apparatus of FIG. 1 (cylinder portion of the web shown in FIG. 3 of the patentto 7) or in the apparatus of FIG. 2 (cylinder 107). The 100 Hinzmann can be omitted and the distribution of periphery of this cylinder has a raster of narrow helical adhesive-coated fields can be selected practically at grooves 132 with a pitch of approximately 45 deg rees. will.

The peripheral surface can be formed with the single It is equally possible to use the improved apparatus thread orwith multiple threads and the cylinder in a filter cigarette making machine, e.g., in a machine preferably comprises an outer layer or shell 132 which 105 know as PROTOS which is also distributed by Hauni is provided with the grooves 132 and surrounds an Werke. In such machine, the apparatus is used to intermediate layeror shell 133 of copperwhich, in apply a coat of adhesive pasteto a continuous web of turn, surrounds a cylindrical core 134 of steel. cigarette paperwhich is draped around a rod-like filler FIGS. 5 and 6 show a modified embossing or of natural, reconstituted andlor artificial tobacco.

engraving cylinderwhich can be used in the apparatus 110 Analogously, the apparatus can be used to apply of FIG. land 2 as a substitute forthe cylinder of FIGS. 3 adhesive paste to a web of wrapping material in a filter and 4.The peripheral surface of this cylinder has a rod making machine wherein the web is draped rasterof recesses or notches 135 bounded byfrusto- around a filler of fibrous or otherfilter material for conical surfaces. The outer layer orshell 136ofthis tobacco smoke.

cylinder is made of chromium oxide which surrounds 115 It is furtherwithin the purview of the invention to a shell 133 of copper and the latter surrounds a discard the viscous material which enters the expan cylindrical core 134 of steel or an equivalent material. sion chamber 12 or 112 and tofill the chamber 4 or 104 FIG. 7 shows one presently preferred mode of exclusively with fresh viscous material. The second sealing the marginal portions of the peripheral surface stream then serves the sole purpose of removing all or 13 or 113 of the cylinder7 or 107. Such sealing is 120 nearly all remnants of the first stream ahead of the desirable in orderto preventviscous material from chamber4 or 104 so as to even further enhance the flowing axially beyond the ends of the peripheral quality of viscous material which is to be applied to the surface. The illustrated sealing means comprises a web 1 or 101. However, and since the quantity of stationary wall 138 which carries a layer 139 of foamed viscous material which constitutes the remaining material acting not unlike an elastic cushion forthe 125 portion of the first stream is small orvery small, the friction bearing 142 which actually contacts the admission of such material (especially upon thorough peripheral surface of the cylinder and is or can be degasification) does not adversely influencethe made of Teflon (trademark) or a similar plastic quality of the material which leaves the chamber 4 or material. It is clearthat a sealing device is provided at 104with the peripheral surface 13 or 113 of the each axial end of the cylinder 7 or 107. 130cylinder7 or 107.

6 GB 2 190 607 A 6 Withoutfurther analysis, the foregoing will sofully reducing step includes reducing the pressure of the reveal the gist of the present invention that others can, material of the second stream to atmospheric by applying current knowledge, readily adapt itfor pressure.

various applications without omitting features, that, 9. The method of claim 7, further comprising the from the standpoint of prior art, fairly constitute 70 step of advancing the second stream beyond the essential characteristics of the generic and specific channel through at least one additional channel and aspects of my contribution to the art and, therefore, on to the supply of viscous material.

such adaptions should and are intended to be 10. Apparatus for applying a coat of viscous comprehended within the meaning and range of material to a running web of paper or the like, equivalence of the appended claims.' 75 comprising means for transporting theweb along a

Claims

CLAIMS first path; a source of pressurized viscous material;

1. A method of applying a coat of viscous material, conveyor means for advancing a first stream of such as polyvinyl acetate glue, to a running web of viscous material in a predetermined direction from paper orthe like, comprising the steps of transporting said source along an endless second path a predeter the Web along a first path; establishing and maintain- 80 mined portion of which is adjacent the first path so ing a supply of viscous material; advancing from the that a first portion of the stream is transferred onto the supply a first stream of viscous material in a predeter- web and the remaining portion of the stream is mined direction along an endless second path having advanced toward the source; and means defining a a first portion adjacent a portion of the first path and a channel adjacent a second portion of said second path second portion upstream of the supply of viscous 85 and said source so that a second stream of viscous material and downstream of said first portion; transmaterial flows from said source into said channel ferring a first portion of the stream onto the web in the counterto said direction to intimately contactthe first portion of the second path so that onlythe remaining portion of the firststream.

remaining portion of the stream advances toward and 11. The apparatus of claim 10, wherein said along the second portion of the second path; and 90 channel defining means includes a portion of said conveying a second stream of viscous material along conveyormeans.

the second portion of the second path counterto said 12. The apparatus of claim 11, wherein said direction so as to establish intimate contact between conveyor means includes a substantially cylindrical the remaining portion of the first stream and the member having a peripheral surface which draws the second stream. 95 first stream from said source and bounds a portion of

2. The method of claim 1,wherein said advancing said channel.

step includes advancing thefirststream by a driven 13. The apparatus of claim 12, further comprising conveyorwhich defines the second path and said means for equalizing the first stream on the peripheral conveying step includes effecting a flow of the surface of said member between said source and the material of the second stream from the supply along 100 predetermined portion of said second path.

the conveyorso thatthe remaining portion of thefirst 14. The apparatus of claim 13, further comprising stream is located between the conveyor and the means for sealing the source in the region of said second stream. equalizing means.

3. The method of claim 2, further comprising the 15. The apparatus of claim 14, wherein said step of establishing along the second portion of the 105 equalizing means comprises a rotor having a second path an open-ended channel one end of which peripheral surface and said sealing means comprises receives successive increments of the remaining a squeegee engaging the peripheral surface of said portion of thefirststream and the otherend of which rotor.

receives successive increments of the second stream. 16. The apparatus of claim 10, wherein said source

4. The method of claim 3, wherein said conveying 110 contains a viscous material with bubbles of a gaseous step includes pumping the material of the second fluid entrapped therein and said channel defining stream into the channel. means includes an expansion zone for gaseous fluid in

5. The method of claim 3, wherein said advancing the viscous material in said channel.

step includes utilizing the conveyorto drawthefirst 17. The apparatus of claim 16, further comprising stream from the supply and said step of establishing 115 means defining at least one second channel between the channel includes using the conveyor as a part of said source and said expansion zone.

the boundaryforthe channel. 18. The apparatus of Claim 17, further comprising

6. The method of claim 3, wherein said conveying a partition between said channels.

step includes entraining at least a part of the remain- 19. The apparatus of claim 18, wherein said ing portion of the first stream with the second stream 120 partition includes a squeegee which is in contact with and further comprising the step of pumping the said conveyor means.

second stream and the entrained part of the remaining 20. The apparatus of claim 10, wherein said portion of the first stream backto the supply. conveyor means comprises an embossing cylinder.

7. The method of claim 3, further comprising the 21. The apparatus of claim 10, wherein theweb is a step of pressurizing the material of the supply and said 125 strip of tipping paper and the viscous material in said conveying step comprises admitting pressurized source is an adhesive, such as polyvinyl acetate glue.

material from the supply into the other end of the 22. A method of applying a coat of viscous channel, and further comprising the step of reducing material, substantially as herein described with refer the pressure of the material in the channel. ence to the accompanying drawings.

8. The method of claim 7, wherein said pressure 130 23.Apparatus for applying a coat of viscous 7 GB 2 190 607 A 7 material to a running web of paper or the like, substantially as herein described with reference to the accompanying drawings.

Printed in the Un[ted 1Cingdom for Her Majesty's Stationery Office by the Tweeddale Press Group, 8991685, 11187 18996. Published at the Patent Office, 25 Southampton Buildings, London WC2A 1AV, from which copies may be obtained.

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