DE3713278A1 - Process and device for applying a flowable composition onto a web - Google Patents

Abstract

A process and a device for executing the process for applying a flowable composition onto a web are described, the composition being taken from a supply as a sheet by means of a circulating removal conveyor and being conveyed to the web, and the composition not transferred to the web being conveyed by the removal conveyor back to the region of the supply The sheet which is conveyed back on the surface of the removal conveyor and not transferred is conveyed through a channel through which fresh composition is forced in the opposite direction. <IMAGE>

Description

The invention relates to a method for applying a flowable mass on a web, the mass by means of of a rotating extraction conveyor as a layer from one Taken stock and conveyed to the web and where the mass not transferred to the web from the removal conveyed back to the stock area becomes.

The invention also relates to a device for Apply a flowable mass to a web with a rotating removal conveyor for removing one Mass layer from a supply, to convey the mass does not pile up to the train and to convey it back the mass transferred into the stock area.

The object underlying the invention is the application of flowable, especially liquid Masses on a track using a method and a To improve the device of the type mentioned at the outset, in particular gas inclusions in the not on the Railway transferred back to the storage area mass should be removed before removal conveyor feeds a new mass layer from the supply.

The solution according to the invention is that which is fed back onto the surface of the removal conveyor a non-transferred mass layer fresh mass along in the opposite direction is promoted. The non-transferred mass can by a channel through which fresh mass is promoted opposite direction (opposite) is pressed.  

It is a preferred development of the invention seen the mass from the surface of the extraction conveyor, preferably a removal roller and is promoted to the web and not transferred Mass is conveyed to the channel, the surface the removal conveyor a boundary surface of the channel forms.

In a further embodiment of the invention, the opposite to the direction of movement of the surface the mass pushed by the removal conveyor through the channel, at least partially contain the returned mass can get to a pump device, the mass returns to the supply from which the removal conveyor Mass discharges as a layer.

If the mass in stock from which the removal conveyor Discharges mass as a layer, is kept under pressure, it is advantageous, according to a training of the Erfin the pressure across the channel, counter to the mass fig is pressed, and at least one other channel preferably to reduce to atmospheric pressure.

The device mentioned at the outset is thus known records that the surface of the removal conveyor with a boundary wall forms a channel, the inlet adjacent to the pressurized supply in such a way that mass against the conveying direction of the removal conveyor rers is pushed through the channel.

An extraction is particularly suitable as an extraction conveyor roller; this can advantageously be a metering roller order that it arises between the two rollers gap affects the layer thickness, d. H. them if possible keeps constant. Can be in the immediate vicinity of the gap  then a scraper can be provided on the metering roller is applied and serves to seal the supply.

In the mass not transferred to the web, which in the supply area is conveyed back often, especially with high viscosity of the mass, trapped gas - especially air bubbles, which when Take out a new layer and / or transfer it Layer on the web can interfere. These Air bubbles that, if they are particularly small, too Micro foam can be called in a relaxation Eliminate the zone in the conveying direction of the removal seen conveyor, is arranged in front of the channel. This be indicates that this relaxation zone changes in terms of direction, pressed through the canal in the fresh mass and takes up residual mass behind which Channel is so that there, especially at Atmo spherical pressure, the small gas bubbles into larger ones who can then stand out from the crowd in the relaxation remove zone.

Is the pressure under which the mass is in stock rela tiv high, so it is beneficial to relax from the pantry to the relaxation zone in at least two steps. The first step can be done take place in the channel according to the invention; to the rest Chen relaxation from an intermediate storage room can be a serve another channel according to the invention. Here can this further space with another against scrapers abutting the surface of the removal conveyor be sealed.

The removal roller can be used as an engraving roller, also anilox roller called, be trained, which depending on the order picture, with the liquid mass is applied to the web, has different profiles. You could use the reels  therefore also referred to as profile rollers.

A preferred application of the application device according to the invention can in a so-called filter approach machine take place in the tobacco sticks by means of glued Connection sheets with filter plugs to filter cigarettes get connected. A sheet of covering paper, cut off from the continuously connecting leaflet with an application device according to the invention with liquid glue, preferably aqueous polyvinylaze did be provided.

The advantage associated with the invention is that the removal of a mass layer by the removal conveyor from the bulk supply and the transfer of Do not mass on the web by air bubbles, e.g. B. by Microfoam. Also located no or little old mass on the circumference of the removal meförderers when this new mass ent from the stock takes, so that also achieved an improvement becomes. The detached old mass from which the air bubbles can escape, because of their relatively small quantity, to be added to the fresh mass again, if this is desirable.

The invention is based on exemplary embodiments explained here.

Show it:

Fig. 1 shows an embodiment of the invention, with single-stage pressure reduction between the supply and relaxation zone,

Fig. 2 shows an embodiment of the invention with two-stage pressure reduction between the supply and relaxation zone,

Fig. 3 is a gravure roll as a withdrawal roller,

Fig. 4 shows details of the profile of the roll according to the arrow IV-IV in Fig. 3 in an enlarged scale,

Fig. 5 shows another embodiment of an engraved roll as a withdrawal roller,

Fig. 6 shows details of the profile of the roll according to the arrow VI-VI in Fig. 5 in an enlarged scale,

Fig. 7 details of a seal of the surface of a profile roller against the escape of liquid mass in the axial direction on an enlarged scale.

In Fig. 1, an application device according to the inven tion is shown. The on a strip-shaped web 1 , the z. B. of paper, cardboard, plastic, textile material, fibers or the like, flowable, in particular liquid mass to be applied is supplied by a pump 2 through a feed line 3 . In the end region of the feed line 3 , a pressurized supply 4 of mass is formed, so that a removal conveyor in the form of a removal roller rotating in the direction of arrow 6 can remove 7 mass on its circumference and convey it to the web 1 . Mass is then transferred from the mass removed in one layer to the web. With 8 a scraper (doctor blade) is referred to, which resiliently abuts the removal roller 7 and seals the supply in the conveying direction of the removal roller 7 . The mass not transferred to the web 1 may contain air bubbles, e.g. B. so-called microfoam, which can not solve at übli cher return to a storage room for mass and can lead to malfunctions in the formation of a new mass layer or its transfer to the web. In addition, it is desirable to enrich the so-called old mass or residual mass with fresh mass if possible.

This is achieved according to the invention in a particularly advantageous manner through a channel which lies between the supply 4 and a relaxation zone in the form of a relaxation chamber 12 . A moving boundary surface of the channel 11 is formed by the surface 13 of the removal roller 4 , the other fixed boundary surface is formed by a fixed boundary or channel wall 14 . Through the channel 11 there is now a flow of mass from the supply 4 to the expansion chamber 12 , which has a shear effect and still adhering to the old mass bubbles, especially the microfoam, to the relaxation chamber 12 . The shear forces can also dissolve as an old mass, at least in the boundary layer area, and convey it to the relaxation chamber. This shear effect is particularly favorable in the case of profiled rolls, as are shown in FIGS. 3 to 6. Through the widening channel 11 microfoam and old mass reach the relaxation chamber 12 , which is so formed that a pronounced vortex (indicated by arrow 15 ) is formed. The walls of the chamber are adapted to the vortex. The air in the microfoam follows the mass flow due to the small size of the bubbles. By wetting the wall and by forces in the vortex, the small air bubbles combine to form larger air bubbles, which then follow the buoyancy on the wall of the relaxation chamber 12 and rise parallel to the vortex. The speed of buoyancy of these large air bubbles is limited, so that an increase in the gas volume per bubble is possible. The uppermost part of the relaxation chamber 12 has an inclination that leads to the automatic removal of large air bubbles. The discharge line 16 for the mass is behind or above the expansion chamber. A counter roller 18 is located at the application point A. The mass flowing out of the expansion chamber 12 is conveyed through the discharge line 16 to a storage container 17 for fresh masses, from which the pump 2 conveys practically fresh and largely foam-free mass to the supply 4 .

The width of the channel 11 and the pressure of the pump 2 can be adjusted, since it is advantageous to adapt both values to one another depending on the consistency of the mass, in particular its viscosity, in order to achieve an optimal shear effect.

Fig. 2 shows a development of the invention, in which a metering roller is provided, and the pressure in the reservoir space in several (two) stages to the relaxation chamber. Components that correspond to corresponding elements of FIG. 1 are designated by the same reference numerals, increased by 100, and are no longer specifically explained.

In the removal area E , in which the removal roller 107 removes mass from the supply 104 , a metering roller 121 is assigned to the removal roller. The scraper 108 is arranged in the immediate vicinity of the gap 129 between the rollers 107 and 121 . The mass passes through channel-like recesses in the fixed channel wall from the antechamber 122 into the actual storage room 104 , from which the removal roller 107 takes mass which is metered by the metering roller 121 . The metered layer is conveyed from the removal roller to the web 101 guided in opposite directions via a deflection roller 123 . The excess mass (old mass, residual mass) remaining on the surface of the removal roller 107 is transferred back to the expansion chamber 112 . The mass flowing through the channel 111 counter to the conveying direction 106 of the removal roller 107 , which detaches the microfoam on the returned old mass, also reaches this relaxation chamber. The mass flowing through the channel 111 can also detach old mass, at least in its separating layer. The detached microfoam or the mass first enter the intermediate space 124 and from there through a further narrow channel 126 into the expansion chamber 112 . Another scraper (doctor blade) 127 , which rests resiliently on the circumference of the removal roller 107 , seals off the intermediate space 124 with respect to the expansion chamber 112 .

The mass flows back from the expansion chamber 112 through the discharge line 116 to the storage container 117 with fresh mass.

According to the embodiment of the invention shown in FIG. 2 and particularly advantageous, mass is supplied by the pump 102 through the feed line 103 to the storage space 128 formed by the scraper 108 , the removal roller 107 and the metering roller 121 , in which the mass supply is under pressure. Through the gap 129 between the rollers 107 and 123, a ground layer is conveyed on the surface of the pick roller 107 to the web one hundred and first The old material which has not been transferred is conveyed back to the storage area, where old air-containing mass is first removed from the further scraper 127 and reaches the relaxation chamber 112 . The remaining on the surface of the pick roller 107, especially in their recesses, the remaining mass residues arrive in the channel 111 under the effect of the shear forces exerted by the counter to the rotational direction 106 of the take-out roller 107 through the relatively narrow channel 111 at relatively high speed flowing mass will. The mass flowing against the direction of arrow 106 first reaches the intermediate space 124 , in which there is a pressure between the pressures in the storage space 128 and the expansion chamber 112 . Through the further channel 126 , the mass then passes into the expansion chamber 112 and from there virtually air-free sen through the discharge line 116 back to the storage container 117th The mechanism of the degassing in the degassing chamber 112 is the same as that described with reference to the expansion chamber 12 .

Due to the described mode of operation, the removal roller 107 can be loaded in the area of the storage space without being adversely affected by air bubbles / microfoam and / or old mass with a new mass layer which is metered into the gap 129 .

The invention thus ensures good wetting, air-free filling of the entire mass system, constant refreshing of the mass and reliable removal of the old mass. If the speed (peripheral speed) of the removal roller 107 changes , a quadratic increase in the melt pressure in the prechamber 122 and the reservoir 128 can be expected. For this reason too, the use of a positive-displacement pump 102 is recommended. The pressure difference between the pre-chamber 122 and ± 0 is decisive for the gap 129 . With a constant gap area, the flow speed is linear on the one hand from this pressure difference and on the other hand also dependent on the ratios of the wetting forces on the surfaces of the rollers 107 and 121 . Corresponding material pairings make it possible to achieve practically constant layer thicknesses on the removal roller 107 , it being possible to keep the speed of the metering roller 121 virtually unchanged. This applies to the higher speed range. At speeds of the metering roller 121 close to 0, a variable layer thickness can be expected, but this can be compensated for by varying the speed of the pump 102 .

In FIGS. 3 and 4 is a so-called gravure roll 7, 107 (also called screen roller) is shown with a fine oblique thread profile. The pitch of the multiple thread can be 45 °. An outer ring 131 with the profile 132 sits over an intermediate ring 133 made of copper on a cylinder 134 made of steel.

FIGS. 5 and 6 show a gravure roll (also called screen roller) 7, 107 having different profiles 135 that resembles a grid of truncated pyramids. The profile ring 136 consists of chromium oxide and sits on a steel cylinder 134 above an intermediate ring 133 made of copper.

Fig. 7 shows an advantageous seal of an engraving roller ( Fig. 3 to 6) against the outflow of mass in the axial direction. A fixed sealing wall 138 is connected to the actual sliding seal 142 , preferably made of plastic (Teflon), via a foam layer 139 , which serves as a spring. Details of the seal are not shown in FIGS. 1 and 2.

By the application device according to the invention Masses of different types continuously added up on tracks will wear. A particularly advantageous example exists in applying liquid glue to a web e.g. B. of paper, Plastic or cardboard, especially if a special glue pattern is to be created. So lets the application device according to the invention in one Provide so-called filter attachment machine to liquid there for glue, e.g. B. aqueous polyvinyl acetate glue (e.g. with 50% water), continuously on a so-called To apply covering paper strips, which then in Covering sheet is cut. With the glued covering leaflets (also called connecting leaflets) then cigarettes (tobacco sticks) with filter plugs to filter connected cigarettes. Such a filter attachment machine the under the name MAX of the company Hauni-Werke Körber & Co. KG, 2050 Hamburg 80, Kampchaussee 8-32, in the The cigarette industry is known in the US PS 42 49 547. The glue application provided there device can by the application device according to the  Invention to be replaced. This doesn't just apply to that glue pattern shown in the aforementioned US-PS, but for any glue pattern, that is to say for flat application Glue with or without a longitudinally unglued agent stripes or for glue pictures with field-shaped recess stanchions in the glue areas.

With the device according to the invention can also glue on a sheet of cigarette paper or a wrapper strips for a strand of tobacco filter material working industry or a strip of wrapping material applied in packaging machines.

Claims (13)

1. A method for applying a flowable mass to a web, the mass being removed from a supply and conveyed to the web as a layer by means of a circulation around the removal conveyor and wherein the mass not transferred to the web is returned from the removal conveyor to the area of the supply is conveyed back, characterized in that a layer of fresh mass is conveyed along in the opposite direction along the non-transferring mass layer conveyed back on the surface of the removal conveyor. 2. The method according to claim 1, characterized in that that the returned on the surface of the removal conveyor conveyed non-transferred mass layer through a channel is promoted by the opposite fresh mass ge is pressed. 3. The method according to claim 2, characterized ge indicates that the mass from the surface of the Ent take conveyor, preferably a removal roller, ent taken and promoted to the train, and that not transferred mass is conveyed to the channel, whereby the surface of the removal conveyor has a limit surface of the channel forms. 4. Method according to one or more of the preceding Claims, characterized in that the opposite to the direction of movement of the surface of the removal conveyor mass pushed through the channel, the mass returned Mass may at least partially include a pump device arrives, feeds the mass back to the supply, from which the removal conveyor discharges mass as a layer.   5. Procedure according to one or more of the preceding the claims, characterized in that the mass in the supply from which the removal conveyor mass as Layer discharges, is kept under pressure, and that the pressure across the channel through which the mass runs in opposite directions is pressed, as well as at least one other channel is preferably reduced to atmospheric pressure. 6. Apparatus for applying a flowable mass to a web ( 1 , 101 ) with a revolving removal conveyor ( 7 , 107 ) for removing a mass layer from a supply ( 4 , 104 ), for conveying the mass layer to the web and for conveying back the mass not transferred to the web in the area of the supply, characterized in that the surface ( 13 , 113 ) of the removal conveyor ( 7 , 107 ) forms a channel ( 11 , 111 ) with a boundary wall ( 14 , 114 ), whose inlet adjoins the pressurized supply ( 4 , 104 ) in such a way that mass is pressed against the conveying direction ( 6 , 106 ) of the removal conveyor through the channel. 7. The device according to claim 6, characterized in that the removal conveyor is formed as a removal roller ( 7 , 107 ), which can be assigned a metering roller ( 121 ) in the region of the supply. 8. The device according to claim 7, characterized in that a scraper ( 108 ) for sealing the supply ( 104 ) in the immediate vicinity of the gap ( 129 ) between the metering roller ( 121 ) and removal roller ( 107 ) is arranged. 9. The device according to one or more of claims 6 to 8, characterized in that in the conveying direction ( 6 , 106 ) of the removal conveyor ( 7 , 107 ) in front of the channel ( 11 , 111 ) a relaxation zone ( 12 , 112 ) for in the mass gases is provided. 10. The device according to one or more of claims 6 to 9, characterized in that between the supply ( 104 ) from which the removal conveyor removes a layer and in which the mass is under pressure, and the relaxation zone ( 112 ) except the channel ( 111 ) at least one further channel ( 126 ) is provided. 11. The device according to claim 10, characterized in that the space ( 124 ) between the channels ( 111 , 126 ) with a further against the surface of the removal conveyor scraper ( 127 ) is sealed. 12. The device according to one or more of claims 6 to 11, characterized in that the removal roller is designed as an engraving roller ( Fig. 3 to 6). 13. Device according to one or more of the preceding the claims, characterized in that the device Part of a filter attachment machine for cigarettes is, through the glue, preferably polyvinyl acetate glue, on a topping strip for joining tobacco sticks and filter plug is applied.