EP0117427A1 - Coating device for applying a foam - Google Patents

Abstract

The device comprises a spreader pipe 10 which is sealable, preferably in a controlled fashion, from one end and which is fillable from the end face and has been provided at its end face with an inflow connection 11 for the medium to be applied. The spreader pipe has been provided with a spreader slot 15 or with variously shaped holes which are directed towards the plane where the foamed liquor is to be applied. At the end face of the spreader pipe opposite the inflow connection it is possible to arrange an outflow connection with a flow control valve and a pressure meter. The outflow connection can end within or above a tank 4. On the inside of the spreader pipe there is disposed at least one displacement body 6 which reduces the foam flow cross-section and whose distance from the inner surface of the spreader pipe is substantially constant. Owing to the resistance offered by the displacement body, it is necessary to make the inflow connection larger in cross-section than the outflow connection, which is sealable in a controlled manner. An essential requirement is that a constant, continuous stream of the foamed medium is transported from one side of the device to the other, the volume on the inside of the spreader pipe being reduced by the displacement body, if it is present, in order to prevent any aging of the foam. The displacement body is predominantly used in the case of operating widths between 3 and 5 m. <IMAGE>

Description

The invention relates to an application device for applying foamed liquor according to the preamble of claim 1.

Application devices for applying foamed liquor to flat goods or webs containing fiber material are known per se. Such an application device is known from DE-05 25 23 062, consisting of an order box which is provided with stumbling stages, the foamed liquor being applied flatly to the goods. The disadvantage of this device is that corners and angles are present in the device, in which foam can remain during the work of the device, age, liquor is released and this old foam flows into the newly supplied foam, which also liquefies, so that considerable There are differences in the consistency of the foam to be applied, which lead to irregularities in the application. No uniform foam application is guaranteed with this device.

Furthermore, from DE-OS 30 34 804 an application device is known which consists of an application box designed as a slot doctor blade, the foam being supplied to this printing order box under pressure. This device has the advantage over the device described at the outset that there are no stumbling stages in the device and that the application does not take place over a wide area but through an application slot. However, this device does not ensure that no old foam remains in any side areas and that there is a relatively uniform inflow to the application slot.

If foam is supplied in different strands, boundary layers form between the individual strands, for example in the case of a cascade feed, and these boundary layers practically form a slide rail, the presence of which makes it possible for one strand to run faster than the other. Even with the training according to DE-OS 30 34 804, it can happen that foam remains in the corner areas and the newly supplied foam is led to the application slot at a different speed than the foam coming from the corner area. This is a disadvantage in addition to the problems described at the outset, namely that the foam lying in the side regions gradually releases liquor by destroying the bubbles and consequently has a different consistency than the foam flowing in the middle.

The present invention is therefore based on the object to provide an application device for a large working width, in which it is ensured that the foam is supplied to the application device absolutely uniformly, carried on within the application device and passed through the application slot onto the goods, and also with different acceptance quantities of the substrate, a uniform inflow of the foam to the application level is ensured without the foam corners and angles causing aging of the foam being present and without boundary layers between differently guided foam strands or foam flows being present.

This object is achieved by the features listed in the characterizing part of claim 1.

With this device, it is possible for the foam supplied to the end of the tube to move uniformly forward inside the application device to the opposite side, without boundary layers being formed between different foam strands, the foam flowing in a radial direction through the application slot and being applied to the goods .

The device is essentially intended to apply a liquor, preferably provided with dye or chemicals, to a flat, preferably fibrous material-containing flat product, preferably through a screen or a stencil, in order to print, dye or wet a product. Simple water can also be applied in a foamed form if a simple wetting process is desired.

The application can be done using the screen printing process or simply through a screen. The screens or stencils can be patterned or unpowered driven or non-driven. In the case of screen printing machines or machines similar to screen printing, it is particularly important that the foamed medium is fed evenly so that the goods are printed and colored evenly.

In addition to paint or dye or chemicals, liquors, latex foam can also be applied as a layer, and the goods can also be treated or coated.

In particular, webs with a fibrous structure, such as textiles of all kinds, including carpets, pile goods, velvet, also nonwovens, but also felts can be considered as the substrate. The transition from non-woven to paper is possible, possibly also solids, e.g. Plastics to be coated.

The main area of application is printing and dyeing.

Appropriate developments of the subject matter according to claim 1 are described in the subclaims.

In the embodiment of the device according to claim 4, there is the possibility that liquor, namely foamed liquor, possibly continuously under pressure, is introduced into the interior of the tube, the relationship between consumption and amount of the liquor supplied being established by the fact that, if necessary, more is supplied as can be consumed, the excess being discharged via the outlet channel, which can be provided with a quantity regulating valve. This prevents air bubbles from remaining in the application tube because the inflow from one end face to the outlet on the opposite end face is uniform and the radial discharge corresponds to the inflow, especially if the quantity regulating valve is set correctly. The discharged, embarrassed liquor can be collected in a receptacle and reused.

When designing the device according to claim 7, the pressure can be kept at the same value, which is particularly important in order to keep the liquor or the foam uniform to apply to the goods, since it can be assumed that, if the quantity taken off is increased, the pressure drops and, conversely, the pressure increases with a reduced decrease. In addition, the optimum pressure can be reproduced again at a later point in time.

If the device is designed according to claim 8, it is achieved that the foam volume inside the application device is reduced, whereby the time between the introduction of the foam and the foam exiting onto the substrate is shortened considerably, aging of the foam is prevented and fresh foam in the application area is available in order, after passing through the stencil and the sieve, to preferably reach the substrate in liquefied form. This applies in particular to application devices with a relatively large working width of e.g. 3 to 5m.

• Fig. 1 ein erstes Ausführungsbeispiel der erfindungsgemäßen Vorrichtung im schenatischen Längsschnitt,
• Fig. 2 die Vorrichtung nach Fig. 1 in schematischem Querschnitt innerhalb einer an sich bekannten rotierenden Siebschablone oder eines Siebes,
• Fig. 3+4 Vorrichtungen im Schaubild im Querschnitt,
• Fig. 5+6 weitere Ausführungsbeispiele einer Vorrichtung im schematischen Querschnitt,
• Fig. 7 eine mit einem Verdrängungskörper versehene Auftragsvorrichtung in Seitenansicht in Schnittdarstellung,
• Fig. 8 ein weiteres Ausführungsbeispiel einer Auftragsvorrichtung in Seitenansicht in Schnittdarstellung,
• Fig. 9 eine Einzelheit des Ausführungsbeispiels nach der Fig. 8,
• Fig. 10 einen Schnitt längs der Linie X - X in der Fig. 7,
• Fig. 11 ein weiteres Ausführungsbeispiel in Seitenansicht in Schnittdarstellung.

In order to achieve a particularly good flow of the foamed medium, the device is designed according to claim 9. This ensures that the foam strand coming from the inflow nozzle can spread out in the end region, to a cylindrical shape or the like. and consequently in the entire intermediate area between the end faces has its full size, which fills the interior of the application device, which is of essential importance for the passage of the foam through the application slot or the application openings in that, seen over the total working width, uniformly throughout the actual tube area Conditions prevail. Several embodiments of the invention are explained with reference to FIGS. 1 to 11. Show it:

• 1 shows a first embodiment of the device according to the invention in schematic longitudinal section,
• 2 shows the device according to FIG. 1 in a schematic cross section within a rotating screen template or a screen known per se,
• 3 + 4 devices in the diagram in cross section,
• 5 + 6 further embodiments of a device in schematic cross section,
• 7 shows an application device provided with a displacement body in a side view in a sectional view,
• 8 shows a further embodiment of an application device in a side view in a sectional view,
• 9 is a detail of the embodiment of FIG. 8,
• 10 shows a section along the line X - X in FIG. 7,
• Fig. 11 shows another embodiment in side view in a sectional view.

The application device 1 according to the invention for applying foamed liquor consists of an application tube 10 closed at the end, which is preferably designed as a round tube, but can also be polygonal. This application tube is designed to be fillable on one side and has an inflow nozzle 11 on one of its end faces, through which the foamed medium is supplied coming from a foam generator 2 in the direction of arrow A indicated. Any foam generator can be used, namely a static foam generator or a dynamic foam generator. Such foam generators are known per se.

On the opposite side to the inlet connection 11, an outlet connection 12 with a closure 13 is provided on the application device 1, this outlet connection can be seen as a closure 13 with a quantity regulating valve. This quantity regulating valve or the closure 13 enables pressure to be built up in the interior 14 of the application tube 10, through which a uniform outflow of the foamed medium takes place through the passage slot or the passage openings 15. Since this results in a uniform pressure in the entire interior 14, the foam is also applied to the goods 3, the depth of penetration of the application medium into the goods 3 being adjustable by controlling the pressure.

The outlet port 12 leads via the closure 13 or the quantity regulating valve 13 to a tank 4 through a pipe 12 '. This tank 4 catches the excess fleet. This can be used again. The outlet nozzle is located centrally in the front of the application device. The application medium can possibly already be supplied to the application device under pressure.

It is essential with this design that the same continuous strand of the application medium leads from one side of the application device to the other.

In order not to have any corners and edges in which old foam can remain, and on the other hand also to ensure that the inflow side of this inflowing foam has the same cross-section right at the beginning of the application tube 10, the end faces of the inflow or the Outlet conical to the interior of the application tube opening extensions of the inlet or outlet nozzle. The largest diameter of the conical extensions corresponds to the inner diameter of the application tube. The end faces 16 and 17 are thus relatively wide disc-shaped parts which carry these extensions 116 and 117.

The formation of the application tube 10 can be different. It is preferably a relatively thin-walled round tube, as shown in FIG. 2. Fig. 2 also shows that there is the possibility to work on a screen or a template 5. This screen or the template can be driven, it can be a stencil belt, a screen cylinder or the like. In this case, the order for the goods 3 is then carried out through the template. Such a template can be used for dyeing, patterning, soaking, moistening or otherwise treating the goods.

As can be seen from FIGS. 3 and 4, there is the possibility of different design of the through openings 15. FIG. 3 shows row arrangements of through openings. Fig. 4 shows an order slot.

5 and 6 show that the application tube 10 does not necessarily have to be round. It can have an oval shape or the shape of a rhombus with rounded corners. Both the oval and the rhombus are preferably upright. The flow to the through-openings, which are outlet cross-sections, is essential, and it is also important that there are no corners and edges in the design which enable old foam to remain.

The idea of the invention is not limited to the exemplary embodiments shown.

In the embodiments shown in FIGS. 7, 8, 10 and 11, a squeegee shoe 110, which has an application slot 110 ′ in the center, belongs to the application device 1. Through the passage openings 15, the foam flows through the goods 3 (FIG. 10), the depth of penetration of the application medium into the goods 3 being adjustable by controlling the pressure. The goods can lie on a printing table in a manner known per se or can be transported through a printing blanket 7.

The supply of the foam is advantageously greater than the outflow, even if it is completely open. The conditions could be such that the diameter is 25mm in the inflow, while the outflow is 12mm or the inflow nozzle 11 is 100mm in diameter, while the outflow nozzle is 60mm in diameter.

The ratio should ideally be 2: 1 or larger, whereby the double size can still be increased and the smaller factor can still be reduced. It is essential in the exemplary embodiments shown in FIGS. 7 to 11, which are particularly suitable for a relatively large working width, that a displacement body 6 is arranged in the interior of the device, this displacement body 6 itself being able to be formed in one part or in several parts. It can consist of solid material, but can also be a tube, whereby it preferably adapts to the inner shape of the interior 14 inside the application device 1. Therefore, the ends 60 and 61 of the displacer 6 are designed conically in accordance with the extensions of the end configurations of the end closings 16 and 17, so that there is preferably a uniform wall distance everywhere between the inner surface of the application tube 10 and the outer surface of the displacer 6 or the outer surface of the tapered ends 60 and 61 and inner surface of extensions 116 and 117.

In the exemplary embodiment in FIG. 7, the inlet connection 11 is kept only slightly larger than the outlet connection 12.

In the exemplary embodiment in FIG. 8, the inlet connection 11 is kept considerably larger than the outlet connection 12, specifically beyond the 2: 1 ratio.

The displacement body 6 can be held in the interior of the application device by means of spacer pins or bolts 8, preferably in a three-point bearing, the pins or bolts going obliquely outwards in the exemplary embodiment in FIG. 7 and being supported on the inner cone 116 and 117. If oval or angular shapes are used here that are not so advantageous, the parts must adapt in relation to each other.

In the embodiment of FIG. 8, spacers 80 are provided, which can be pushed or threaded onto the tubular middle piece 62. These spacers leave the lower space in the area of the supply of the application agent free and can still have passage cross sections 81. Through these spacers with their passage cross-sections, which can also be selected in different sizes, for example to ensure pressure equalization up to the rear end of the device, are simply threaded onto the displacement body 6 and held on its outer surface.

FIG. 10 shows the section X - X of FIG. 7, but the device is inserted into a sieve or a template 5. A cylinder template is shown, but this is only hinted at. The device lies with the template on the goods 3 and a printing blanket 7, as already described.

11 shows an embodiment in which the displacement body 6 consists of different parts, namely a front part 60 and a rear part 61 and a central part 62. All three parts can be screwed together.

It is essential that this device prevents the foam in the application element from aging. Otherwise it would excrete liquid and lead to difficulties in the pressure area. The displacement element or the displacement body 6 considerably reduce the volume inside the application device, so that fresh foam is constantly available for the application to the goods. If less volume is available, less liquor excretion from the foam is to be expected, i.e. a smaller amount of aging foam or no old at all foam occurs. The reduction in space by means of one or more, preferably concentrically inserted, displacement bodies has the advantage that the foam feed moves from one side to the other, pressure builds up inside the device: for the foam to escape in the direction of the application surface4.

A relatively large body diameter should be chosen in relation to conventional device diameters in order to achieve sufficient stability of the displacement body and to prevent the displacement body from bending in the middle. In relation to the standard template and with a diameter of the application device of 120 to 200 mm, the displacement body could be designed with a diameter of about 80 mm and above. These are just examples.

As already mentioned, the displacement body can consist of several parts. It is essential that it should be smooth-walled and that the interior of the application device should be smooth-walled, if possible, so that there are no corners and edges where old foam can accumulate. As already mentioned, the application medium can be fed to the application device under pressure, preferably under continuously adjustable pressure. The arrangement in the interior 14 of the application device can be adjusted and regulated by the arrangement of the closable outlet connection or outlet channel and the arrangement of the quantity regulating valve. The flow control valve can be set depending on the throughput speed of the goods. It is also important that the displacer can be completely washed around by the foam, that it lies practically floating in the foam strand and that the side distances to any walls are the same if possible.

The inlet connector 11 and the outlet connector 12 should always be centrally located in the most varied possible shapes of the application device, which can be round, oval or polygon. This central location has the advantage of a uniform flow in the area of the application tube and also a uniform inflow to the displacement body.

As can also be seen from the figures, between the foam outlet opening of the application device 1 and the closure 13 designed as a quantity regulating valve, a manometer 19 serving as a pressure measurement indicator is provided in the outlet connection 12. This makes it possible to keep the pressure constant in a particularly simple manner. It can be assumed that by keeping the pressure constant, an equal amount of foam is applied to the goods 3, since with an increased decrease and even supply the pressure would drop, while with a reduced decrease and equal supply the pressure would increase. This pressure measuring and display device is an essential component for operational safety. Furthermore, it is particularly advantageous that the pressure is reproducible, which is particularly important since, for example, the pressure has to be set depending on the material to be printed.

The idea of the invention is not restricted to the exemplary embodiments shown. It is essential that the application medium can also be fed to the application device under pressure, preferably under continuously adjustable pressure. The arrangement in the interior 14 of the application device can be adjusted and regulated by the arrangement of the closable outlet nozzle or outlet duct and the arrangement of the quantity regulating valve and the pressure measuring device. The flow control valve is adjustable depending on the throughput speed of the goods. The removal of the remaining foamed liquor can also be designed differently. The outlet nozzle or the outlet channel can open into or above the tank 4.

The features disclosed, individually and in combination, are regarded as essential to the invention insofar as they are new compared to the prior art.

Claims (11)

1. Application device for applying foamed liquor, preferably through a sieve, a stencil or the like, in particular for dyeing and printing flat goods or webs, characterized in that the application device (1) is tubular and has an application slot or Passage openings (15) is provided, and the application tube (10), which can preferably be closed at the end, is designed to be fillable on one side and is provided on its opposite end face with an inlet connection (11) for the application medium. 2. Application device according to claim 1, characterized in that the application medium can be fed under pressure of the application device (1). 3. Application device according to claim 1 and 2, characterized in that the application medium can be fed under continuously adjustable pressure of the application device (1). 4. Applicator according to claim 1, characterized in that the applicator is provided on the end opposite the inlet with a preferably closable outlet nozzle (12). 5. Applicator according to claim 1 and 4, characterized in that the outlet nozzle (12) is provided with a quantity regulating valve or a closure (13). 6. Applicator according to claim 5, characterized in that the quantity regulating valve or the closure (13) is adjustable depending on the throughput speed of the goods. 7. Application device according to claim 1, 2 and 6, characterized in that a pressure measuring device (19) is arranged after the outlet, but before the locking and regulating device. 8. Application device according to claim 1, characterized in that in the interior of the application tube (10) at least one displacement body (6) reducing the foam flow cross section is arranged. 9. Applicator according to claim 1, characterized in that the end faces (16, 17) of the inflow and / or the outlet are provided with conical extensions to the interior of the application tube (10) opening the inflow and / or outlet nozzle. 10. Application device according to claim 1, characterized in that the application tube (10) can be flowed through from one end face to the other by the application medium and one or more radial passage openings (15) or the like directed to the application level. having. 11. Applicator according to claim 8, characterized in that the displacement body adapts in its shape to the shape of the interior (14) of the applicator tube or the applicator.

Images