The invention relates to a web conveying device with a space surrounded by a housing, through which a material web is conveyed and / or with an air tunnel for deflecting the material web essentially without contact after exiting the housing, and a guide device for use in the web conveying device for stabilizing the web Run the material web in the area between the exit of the material web from the room and the outlet from the Airturn.
Web conveyors are used, for example, in the coating of a moving material web. To achieve a high-quality order result, attention must be paid to the order conditions, in particular when finishing paper webs. Above all, it is also important to keep the moving web free from vibrations. Due to the running speed of the material web, however, it happens at various points within the device that an air cushion which surrounds the material web leads to a lifting of the material web. To allow a more constant and undisturbed run of the web, it is for example from the DE 198 29 449 A1
It is known to provide suction devices for sucking air entrained with the material web and / or the veil. In addition, there is provided a dynamic pressure determination device which determines the pressure of the air which accumulates in the direction of travel of the material web upstream of the line of impact of the haze on the material web. A control device controls the suction power of the suction device in dependence on the back pressure determined by the dynamic pressure determination device. The suction devices are arranged in the region of the impact line of a veil or curtain on the material web on the upper side of the material web and in the region of the inlet of the material web in the deflection roller at the veiling applicator on the underside of the material web. The provision of these two suction devices is intended to prevent fluttering of the material web in the application area.
From the US 4,287,240 A
For example, a curtain applicator is known. In this a shielding device is provided to protect the curtain against a disturbance of the air flow. This shielding device is made of a perforated material that functions to distribute the airflow so that its velocity is reduced and thereby its tendency to disturb the curtain. The perforated material is provided either only partially in the area of the curtain or surrounding it on different sides.
From the DE 100 57 729 A1
Also, a curtain applicator is known. With this device, two layers of a liquid or pasty application medium are applied to a web. To improve the order result, at least one guide element is arranged in the path of the curtain or curtain, which steers the curtain in a desired path. In order to increase the quality of the order result, it is likewise disclosed there, in the area between the application units, to provide a device for influencing the pressure prevailing there and that at the application medium curtains and the material web. If an overpressure is generated in the area between the two commissioned works, a stabilization of both curtains can take place among others, whereby their tendency to flutter is reduced. In addition, a Leitschaber is arranged in the region of the second applicator, which is to bring about a weakening of an entrained by the material web air boundary layer and is employed against the material web.
Also from the DE 44 15 581 A1
is a paper-coating device is known in which a running paper web is guided via web deflection devices after the coating operation without contact by means of an air cushion. According to this document intentionally with the web mitströmendes air cushion is formed in order to achieve an extraordinarily quiet and stable web guide on the circumference of the guide roller for the paper web. The formation of the air cushion can be supported by an air nozzle. This is done especially when the web speeds of the paper web are relatively low. The air is blown in a desired area between paper web and guide roller. Alternatively, an air blast roll is used with a perforated roll shell. Particularly advantageous is mentioned in this document that due to the targeted generation of an air cushion, a rotational air flow and no radial impact flow, as in stationary Airturn-Leitvorrichtungen, can be generated. As a result, a special protection of the paper web is to be made possible.
From the JP 03-123658 AA
a curtain coating apparatus is known, in which also the formation of irregular coatings due to entrained with the paper web air can be avoided. For this purpose, an L-shaped air shield is provided, which is arranged with one leg parallel to the curtain and another leg parallel to the material web upstream of the line of impact of the curtain on the material web. The minimum gap between the leg parallel to the web and the web itself becomes 1 mm or less measured, with this leg does not touch the web.
Another device for sucking air in the region of a deflection roller for a material web is in the US 5,624,715 A
disclosed. The entrained air with the web is sucked through a slot in the region of an edge of a suction device. In addition, an air supply opening is provided to send air at high speed from above against the surface of the web, wherein the air is drawn at a lower speed over the slot.
Also in the JP 10 277459 AA
and the US 2003/0 039 761 A1
Umbrella devices are employed in the area of the curtains of the application devices against the material web and the curtain falling vertically so that entrained with the material web air does not interfere with this curtain. Such devices in the form of air flow and air boundary layer scrapers are also described in the article "Curtain Coating - A Novel High Precision Painting Process" by B. Méndez and H. Morita, pp. 1492-1497 in the Wochenblatt für Papierfabrikation 22, 2001 , The provision of a so-called "air knife" in front of the nozzle head of a curtain coater and a vacuum box in this area to cut off entrained air turbulence affecting the stability of the curtain is described in the article "Practical Experiences with Curtain Coating", D. Stegner, p. 1586 -1589, in "Wochenblatt für Papierfabrikation 23/24, 2002, described.
The entire prior art deals with the stabilization of a coating medium curtain, wherein only after influences that upstream, d. H. spatially and temporally before the existence and the occurrence of a line of impact of the order medium curtain lie on a material web is sought.
The present invention is therefore an object of the invention to provide a web conveying device and in particular a curtain application device through which a material web to be coated can be passed through smoothly, with influences downstream of the removal of a coated material web from a housing in which the order of a coating medium, to react to the stability of a coating medium curtain should be avoided.
The object is achieved by a web conveying device according to the preamble of claim 1, characterized in that at least one guide is provided in the region of the exit of the material web from the housing, which narrows in the web running direction substantially funnel-shaped and one or more backflow devices at the inlet of the material web in the and / or outlet from the Airturn for controlled backflow of air between the web and Airturn surface are provided. Further developments of the invention are defined in the dependent claims.
This creates a web conveying device for conveying a material web, with which it is possible to reliably prevent, or at least severely restrict, an uneven running or web fluttering of the material web in each region through which the material web passes. When using the device and devices in a curtain application device, the space is z. As an order space, which is usually air conditioned and more or less demarcated from the environment. Here, the material web at the exit from the order space is subject to turbulent air flows due to their speed and the entrained air as well as the climate change. This results in uncontrolled air currents and turbulences, whereby the material web partially lift off from a supporting roller and run restless or flutter in the entire area between the roller and the outlet from the contract area. As a result, the uniformity of the coating order may suffer. This problem can be remedied with the guide and / or backflow devices according to the invention. Due to the funnel shape of the guide (s), air turbulence which arises in the air space above the material web between a line of impact of a coating medium curtain and the exit of the material web from the application space at high web speeds can be alleviated or eliminated. Otherwise, the air turbulences ensure that a free-falling application medium curtain is caught by them and moved undesirably. By providing in particular the funnel-shaped guide device (s), the line homogeneity in the region of the impact line of the application medium curtain can be improved. Although the baffle (s) is located downstream of the line of impact in the web running direction, its design can nevertheless influence and improve the uniformity of the impact line. At very low web speeds, there may be an imbalance between this air cushion and the air cushion generated in Airturn due to the small amount of air entrained in the air in the area between the impact line of a Auftragmediumsvorhangs on the web and their exit from the order space. It is therefore possible that the air emerging at the Airturn air is moved counter to the direction of web travel and can get into the exit of the web from a housing surrounding the order space. Likewise, the air entrained with the material web at the exit of the material web from the housing back-stowed or by the back-flowing Air are forced back into the housing. As a result of these disturbances, in the case of the devices of the state of the art, in addition to web flutter, an undesired deflection of a coating medium curtain of a curtain application device can occur, not by in situ generated air turbulences, as described above, but by the foreign air which has penetrated with the direction of web travel in the opposite direction of movement. This means that the curtain no longer hits in the form of a straight line as a line of impact on the material web, but in the form of a regular or irregularly deformed wavy line. The result is line distribution irregularities in the line application on the material web, which mean a loss of quality of the product produced. In extreme cases, the curtain can be deflected so much that it splits, making the product completely unusable, at least in this area. Both disturbances described above, which are due inside and outside the order space, have an influence on the line thickness, the weight per unit area, etc. of the product to be produced, whereby they can be kept in the desired value range when using the guide and backflow devices according to the invention.
Due to the provision of a guide in the area of the exit of the material web from the application space, this web flutter can be prevented and thus the coating quality improved or the good coating quality maintained and not disturbed. Due to the advantageous funnel-shaped constriction of the guide, the possibly turbulent air flow is calmed and thus counteracts a web flutter and a deflection of the application medium curtain. As a funnel-shaped here is a closed one-sided constricted structure, but also understood to each other employed baffles, which exert a conductive function. By providing one or more backflow devices at the inlet into the air circuit, excessive and irregular lifting of the material web from the air stream and a backflow of the air cushion of the air stream into the application space can also be counteracted there. Also in the region of the outlet of the material web from the Airturn it can come in the devices of the prior art to an excessive lifting of the material web due to the surrounding air flow. By providing the one or more backflow devices according to the invention, controlled air between the material web and the Airturn surface between the inlet and the outlet of the web into and out of the Airturn backlogged and thus calmed, so that a web flutter can be suppressed with the effects described above , The otherwise tangential flowing away from the Airturn surface air is calmed by the backwater.
Preferably, the guide is positioned in the manner of a diffuser in the outlet opening of the housing. Just by providing a guide device in the manner of a diffuser in the outlet opening of the housing, the air is trapped on the inside of the housing wall within the housing through the wide funnel opening and calms on the outside of the housing, the material web surrounding out of the room. Since such an outlet opening is present in the housing in order to be able to transport the material web from the interior of the housing to the outside, such a funnel-shaped, designed as a diffuser guide can be easily retrofitted to an existing web conveyor, as they are merely inserted into the outlet opening will need. It is therefore not necessary to acquire a completely new device, which brings a significant cost savings with at the same time possible improvement in the quality of the conveyed material web.
The guide device preferably extends beyond the width of a housing wall and can be fastened or fastened thereto. In this way, it is advantageously possible to provide a calming of the air flow surrounding the material web in a longer range. In most cases, a housing wall will not be particularly thick, so that in the event that the funnel-shaped guide is thick only as long as the housing wall, if necessary, no complete calming of the air flow would be possible. Characterized in that the length of the guide can be chosen arbitrarily, that can also extend beyond the width of the housing wall out, it is possible to produce a complete calming of the air flow.
Preferably, the guide is formed projecting at its narrow end in the edge region. As a result, the air does not flow out of the diffuser or the funnel-shaped guide device via a hard, possibly turbulence-leading, tear-off edge, but instead experiences a further gentle steering to the outside from this funnel-shaped guide device. Turbulences can thus be advantageously avoided in this area.
The opening width of the guide device at the end facing the interior of the housing is preferably between 100 and 400 mm, in particular 200 mm. The opening width of the guide device is preferably between 20 and 50 mm, in particular between 30 and 40 mm, at the end arranged in the region of the outside of the housing. Of course, other dimensions can be selected, wherein preferably such a ratio between the opening width of the guide is selected in the interior of the housing and on the outside of the housing, that sufficient calming of the air flow surrounding the web is possible. When selecting the dimensions, the speed of the material web is also advantageously taken into account, since the air flow surrounding the material web is designed differently, depending on the speed with which the material web moves through the web conveyor device.
Preferably, the at least one backflow device at the inlet and at the outlet of the Airturns connected to the Airturn or connected and dimensioned so that it covers at least the width of the material web. By covering the width of the material web can be generated on the entire width, a calming of the air flow and prevents the air cushion from the Airturn unintentionally exits and flows back against the web running direction to the order space. In addition, it is advantageously avoided by the desired induced immobilization of the web in Airturn that strikes the material web to adjacent rigid components, which can lead to a material web breakage in the worst case. The at least one backflow device preferably protrudes so far beyond the surface of the air tunnel that the air gap between the surface of the air tunnel and the material web surface is almost completely covered. Particularly preferably, the at least one backflow device protrudes so far beyond the surface of the Airturns that the air gap between the surface of Airturns and the material web surface between 10 and 30 mm, in particular between 15 and 20 mm. As a result of the backflow device covering almost the entire air gap between the surface of the air tunnel and the material web surface, the air between the material web surface and the surface of the air stream is blocked and thus the air flow is calmed. Such a controlled backflow of the air and thus immobilization of the web can be particularly preferably produced at low web speeds of 150 to 250 m / min, but also at higher web speeds of about 300 to about 1100 m / min. In order to maintain a sufficient distance between the backwater device and the surface of the material web, this is in particular between 10 and 30 mm. Depending on the web speed, other distances may prove advantageous. If the distance is chosen too large, the backflow of air can no longer be optimal. If the gap chosen too small, there is a risk of striking the moving material web on the backwater device, which may possibly lead to a web break. Both effects should be avoided and taken into account when dimensioning the distance.
Preferably, the at least one backflow device is designed in the manner of a guide plate. Such a baffle can be particularly easily attached to an outer wall of the Airturns and is space-saving and effective.
Preferably, the at least one backwater device at least one recess, recess or opening for engaging a Aufführdrachens or other, the material web leading device. Particularly preferably, the at least one backflow device in the inlet region of the Airturns with a recess, recess or opening in an end section and the at least one backwater device in the outlet region of Airturns also provided with a recess, recess or opening in an end-side section. In particular, the recess, recess or opening on the Aufführdrachen or the material web in particular when performing leading device adapted depth, in particular a depth of 10-20 mm, in particular of 15 mm. As Aufführdrachen an auxiliary device is referred to, by means of which a material web can be passed through the machine when performing after a machine downtime or after a material web break. Such a Aufführdrachen consists in particular of a plastic rail and, for example, a 20 m long belt, similar to a roller shutter belt. The material web is fastened to the guide rail on a width of, for example, 600 mm on the plastic rail and then guided by means of a belt at a speed of 20 m / min through the machine. In order not to obstruct the application of such a performance kite, the recess, recess or opening are provided in an end-side portion of the backflow devices. Also with regard to the other dimensions, the recess, recess or opening is advantageously adapted to the dimensions of the feeding kite or a corresponding device for guiding the material web. As a result, the operation of a performance kite or a similar device is not disturbed in advantageous calming the air flow surrounding the material web by the backflow devices according to the invention.
The at least one backflow device preferably encloses an air storage space at the outlet of the material web from the air stream with the material web and the outlet end of the air stream. Particularly preferably, a gap is provided between the end of the at least one backflow device facing the material web and the surface of the material web, in particular a gap of 10-30 mm, in particular of 15-20 mm. The air storage space at the outlet of the material web from the Airturn is generally larger sized than the Air storage at the inlet into the Airturn. However, the gap between a front surface or edge of the backwater device and the material web is preferably dimensioned similar to the inlet, so as not to jeopardize the desired immobilization of the air flow through the resulting air space by an excessive gap and on the other hand, an unintentional striking the material web to the Backflow device to avoid due to a too small gap. The at least one backflow device is preferably arranged with its end facing the material web to a roller, in particular a spreader roller, facing away from its surface deflecting the material web. As a result, the material web undergoes a soothing intervention anyway in the deflection over the roller, which is reinforced by the provision of the backwater device in this area.
Preferably, the at least one backflow device in cross section is substantially S-shaped, in particular formed by connecting two in cross-section L-shaped elements. Alternatively, in principle, a C-shape can be formed. By the S or C shape, it is advantageously possible to form a space for backflow of air, which is dimensioned sufficiently large to ensure a real calming of the material web or the air flowing around this material web. As well as by the funnel-shaped guide in the region of the exit of the web from the housing above and below the web a uniform air inflow is possible, especially at critical low web speeds between 150 and 250 m / min or even at higher web speeds between about 300 and 1,100 m / min, can by the relatively large backwater between the backwater at the outlet of Airturns and the backwater at the inlet of Airturns a complete stabilization of the web and the air flow in the web from the inlet to the Airturn to the outlet of this and also back to the contract room and thus carried out a vibration-free and flutter-free movement of the web.
A guide device for use in such a web conveying device for stabilizing the run of a material web from a housing is advantageously configured in a funnel shape and provided with at least one device for fastening to a wall of the housing. This type of guiding or stabilizing device is, as already mentioned above, used in the region of the housing wall, where the material web emerges from the housing. For the region of the inlet of the material web in the Airturn for substantially contactless deflection of the material web, a backflow device is advantageously rail or strip-like and provided with at least one means for attachment to an outer wall of the Airturns at the inlet of the material web in the Airturn. For use in the region of the outlet of the material web from the Airturn for substantially contactless deflection of the material web is a backwater advantageously L-shaped, S-shaped or C-shaped and with at least one means for attaching to an outer wall of the Airturns at the outlet of the web provided the Airturn. When using an L-shaped element, it is preferably connectable or connected to a further L-shaped element for forming an S-shaped or C-shaped profile in order to form a large air storage space.
Particularly preferably, the funnel-shaped guide device has a substantially round, oval, polygonal or polygonal cross-section, in particular comprises guide elements set against each other. However, it can also have an arbitrarily shaped cross-section. Usually, the cross-sectional shape of the guide also results from the shape of the outlet opening in the housing, from which the material web emerges from the interior of the housing to the outside. In general, this outlet opening will be formed regularly and the guide device have a rectangular cross-section.
For a more detailed explanation of the invention will be described in more detail in the following embodiments with reference to the drawings. These show in:
1 1 is a schematic diagram of a section of a web-conveying device designed according to the invention in the region of a housing and an air-line surrounding an application space;
2 a detail view as a side sectional view through the region of the exit of the material web from the housing according to 1 .
3 a detailed view of the area of the inlet of the material web in the Airturn according to 1 .
4 a plan view of the inlet area at Airturn with inventively pronounced guide with recess for a performance kite,
5 a detailed view of the outlet of the material web from the Airturn with inventive backwater device according to 1 , and
6 a plan view of the backwater device according to 5 ,
1 shows a side view of a section of an inventive equipped Rail conveyor 1 with an order space 2 for applying a functional or finishing layer to a material web 4 and this order space 2 surrounding housing 3 , Through the web conveyor 1 becomes a material web 4 promoted. The order space 2 is in particular air conditioned and of the housing 3 completely surrounded, with the housing 3 an entrance opening 31 and an exit opening 32 for the material web 4 having. The through the entrance opening 31 in the order space 2 occurred material web 4 will be within the order space 2 coated. For this purpose, it is first via a guide roller 5 in the area of a Luftgrenzschichtabstreifers 6 diverted. The air boundary layer scraper 6 leads to a calming of the material web 4 surrounding air flow and strips it from the application of a medium, in particular a color or other coating. The material web 4 may be, for example, a paper or board web.
From a curtain applicator 7 with an application nozzle, a curtain will follow 8th delivered on the web 4 impinges and is thus applied in their further movement as a layer. Hereby, the functional layers or finishing layers can be applied to the material web 4 be applied. With a so-called "curtain coater", a precisely defined liquid film is applied directly to the surface of the material web without contact and without excess 4 applied. For example, web speeds of the material web 4 within the web conveyor 1 For example, provided for inkjet paper grades of about 300 m / min at a basis weight between 80 and 200 g / m 2 or for carbonless paper of about 1100 m / min at a basis weight of 50 g / m 2 . Here, the lower basis weight quality groups are particularly susceptible to web flutter, which is understandable as these grades indicate a thinner paper which, of course, tends to flutter in the airflow rather than thicker paper.
After the application of a medium, the coated material web 4a through the outlet 32 out of the case 3 out, behind the curtain applicator 7 another deflection roller 9 for deflecting the material web 4a is provided. In the outlet 32 is a funnel-shaped designed according to the invention guide 10 arranged further down the closer 2 is described.
Outside the case 3 becomes the material web 4a via a spiral roller 20 before entering an airturn 21 diverted. The Airturn 21 is formed in the shape of a circle segment. The Airturn 21 serves for contactless web deflection, especially for paper and board material webs. On the Airturn 21 a Tragluftpolster is built. In the area of the inlet into the Airturn 21 is a backwater device 40 arranged. This gets closer to the 3 and 4 described.
At the outlet of the material web 4a from the Airturn 21a is another backwater device 50 arranged closer to the 5 and 6 is described. In the area of the second backwater device 50 is a spreader roll 22 on the underside of the material web 4a arranged. Below is the material web 4a still through a breast roll 23 deflected and further downstream or down to a dryer, the in 1 is no longer shown, directed.
In the following, the funnel-shaped guide device designed according to the present invention will be described first 10 with reference to 2 be described in more detail. So far, it was common in the area of the outlet 32 the material web 4a from the housing on both sides of the housing wall 33 Apply baffles, which over the outlet opening to the web 4a to endure indicative. As a result, however, before the baffles, behind this and in particular between these particularly strong turbulence, which creates uncontrolled air currents and fluttering of the web 4a is caused. According to the invention is now, as in 2 in detail can be seen particularly well, the funnel-shaped guide 10 in the exit opening 32 arranged. The outlet opening 32 does not need to be formed funnel-shaped for this purpose, as the funnel-shaped guide 10 with fasteners 11 is provided in the form of plates with openings 12 are formed. Through these openings screws or the like fasteners 13 for fastening to the housing wall 33 be put through, in 2 are only indicated.
The fasteners 11 are firmly on the body of the funnel-shaped guide 10 attached, in particular welded or soldered there. The funnel-shaped guide 10 can be made of metal or even, for example, plastic and optionally in one piece with the funnel-shaped guide, for example in the casting process, be formed.
The funnel-shaped guide 10 protrudes both on the inside 34 as well as on the outside 35 of the housing 3 over the housing wall 33 out. The funnel-shaped guide 10 extends z. B. over a projected length l of about 200 mm. Depending on the web speed, it can also be chosen longer or shorter. Their diameter D at the air inlet in the area of the wide end 14 the funnel-shaped guide 10 is For example, 200 mm, whereas the diameter d in the region of the narrowed end 15 the guide 10 for example, between 30 and 40 mm can be. Again, any other dimensions can be chosen, depending on how the other dimensions of the material web 4 and / or how high the web speeds of the material web 4 are.
In the area of the narrowed end 15 cantilevers the funnel-shaped guide 10 a little outward. Through this cantilevered section 16 no turbulence caused, but for the air flow an undisturbed transition from the funnel-shaped guide 10 provided for outside. Alternatively, a straight conclusion, ie the formation of an edge, can also be provided here. However, this is preferably not rugged, but rounded to avoid turbulence in this area as possible.
The 3 and 4 show the backwater device at the inlet of Airturns 21 together with the spiral roller 20 and the Airturn 21 itself. The spiral roll 20 is just before the inlet of the material web 4a in the airturn 21 arranged. In this embodiment, the Airturn 21 a rounded wall 210 , a straight wall 211 at the inlet, a straight wall 212 at the outlet (s. 5 ) and a back wall 213 on, which is also just trained. On the straight wall 211 at the inlet of Airturns 21 is the first backwater device 40 arranged. This backwater device 40 is designed in the manner of a baffle. This means that it is designed as a long narrow plate-shaped element, which via fastening means 41 For example, screws, rivets, etc. (in 3 only indicated) on the straight wall 211 of Airturn 21 is attached. This can be particularly well the top view of the first backwater device 40 according to 4 be removed. It can also be seen here that the baffle or the backwater device 40 at its left in the direction of web travel 43 a recess 44 whereas the right end 42 is formed without such a recess. The recess 44 is used to perform a performance kite, as already described above, or a corresponding device for feeding a material web 4 after machine downtime or other malfunction. In principle, the guide plate can also be formed without such a recess, if a performance kite or a similar device are not provided. The recess may for example have a depth t of 15 mm.
To pull in the web 4a in the airturn 21 and for carrying air with the material web 4a a sufficient gap 46 between the material web 4a and a front edge 45 the first backwater device 40 or the baffle, is the backwater device 40 so far over the surface 214 the rounded wall 210 in addition, that between the material web surface 24 the material web 4a and the front edge 45 the backwater device 40 A gap 46 from Z. B. 15-20 mm remains. Due to the special arrangement of the spiral roller 20 this also corresponds to the gap between the spiral roller 20 and the front edge 45 the baffle or the backwater device 40 , as 4 can be seen.
In web direction of travel, the entrained air accumulates during the further running of the material web 4a behind the baffle or the first backwater device 40 , What 3 can be removed. This can immobilize the web 4a be generated because a more or less static air cushion (in 3 indicated by dots) between the web 4a and the surface of the airturn 21 forms. Also an exit of the air cushion from the Airturn 21 contrary to the web running direction can be avoided.
This air cushion continues to spread in web direction of travel and subsequently fills at the outlet of the Airturns 21 an air storage space 51 passing through the second backwater device 50 in connection with the material web 4a is formed (see 5 and 6 ). The backwater device 50 has an L-shaped element 52 and another L-shaped element 53 on. These two elements are about fasteners 54 interconnected, namely by welding, as in 5 indicated. Instead of two L-shaped elements 52 . 53 An S-shaped element can also be used. In principle, the use of a C-shaped element is possible, in which case the air storage space 51 with otherwise the same training and dimensions of Airturns 21 and the backwater device 50 is formed larger, since the attachment is not, as in 5 shown pointing away from the airspace at the straight wall 212 at the outlet of Airturns 21 takes place, but pointing to the airspace.
Also the L-shaped element 52 is with a recess 55 provided at its one end. The recess 55 can z. B. have a depth t of 15 mm. In the present case this is the left end 57 whereas the right end 56 without such a recess 55 is provided. Also this recess 55 in turn serves to insert a Aufführdrachens for listing the paper web in this area.
Between a front edge 58 of the L-shaped element 52 and the surface 24 the material web 4a In turn, a gap is provided to the material web 4a between the spreader roll 22 and the front edge 58 the second backwater device 50 to carry out without problems and without damage. This gap 59 is for example 15-20 mm. Due to the generation of the air storage space 51 gets through the gap 59 only a small amount of air with the material web 4a carried. There is thus no air turbulence in this area and in the air storage space a complete calming of the air, so that a flutter of the web 4a can be prevented here as well.
The guide and backflow devices described in the foregoing and shown in the figures 10 . 40 . 50 are particularly suitable for use in coating paper webs. However, they are also good for the coating of other material webs 4 , In addition to the embodiments of guide devices described in the foregoing and shown in the figures 10 and backwater facilities 40 . 50 Many more can be formed, each behind a room, through which a material web 4 is moved through, in the region of the exit of the material web 4a are provided from the room and possibly when entering the room to prevent a web flutter and an unwanted deflection of a Auftragmediumvorhangs or at the inlet and / or outlet of the web 4a into or out of an Airturn 21 ,
LIST OF REFERENCE NUMBERS
- Rail conveyor
- order room
- coated material web
- Curtain applicator
- funnel-shaped guide
- Wide end
- Narrowed end
- Projecting section
- Spreader roll
- breast roll
- Surface material web
- inlet opening
- outlet opening
- Inside of the housing
- Outside of the housing
- first backwater device
- Right end
- Left end
- Front edge
- second backwater device
- Air storage
- L-shaped element
- L-shaped element
- Right end
- Left end
- Front edge
- rounded wall
- straight wall at the inlet
- straight wall at the outlet
- rear wall
- projected length
- Diameter at 14
- Diameter at 15
- Depth of 44