DE3034802A1 - Foamed medium application - uses suction to draw foam through screen onto the fabric - Google Patents

Abstract

The foamed medium is contained in a zone above the screen, and is drawn into the fabric by suction, without pressure on the medium. After the suction point, there can be a mechanical pressure or scraper action on the foamed surface. The screen or intermediate screen carrier (4) on the fabric (1) is a perforated plate, a grid, netting, woven wire material, a screen drum or stencil, moving either with the fabric or travelling independently. The tubular medium feed (2) is located above the screen (4), for the foam to be held (50) without pressure. A pressure cloth (3) is placed under the fabric (1) but above the suction unit (6) to act as a permeable fabric carrier. The applicator roller or scraper lies after the suction unit in the direction of fabric travel. The medium feed (2) is controlled to deliver foam according to the rate of foam consumption, using an adjustable level indicator (7) connected to a supply pump. A variable vacuum pump (60) gives an adjustable rate of suction (6) to draw the foam through the fabric, according to the volume of foam in the holding zone (50). The screen (4) is a continuous web. The various process parameters are monitored for use by a computer with digital display for process control. The process gives a constant and controlled application of foamed dyestuff, as the bubbles break up on the screen instead of on the fabric surface, and fluid inconsistencies are eliminated.

Description

Method and apparatus for uniform application

from liquid treatment liquors to textile fabrics The invention relates to a method and a device for the uniform application of liquids Treatment liquors on textile fabrics, the supply of the liquor to Device in foamed form of the same takes place with a device for foaming the liquor under pressure from a mixing chamber designed as a foam generator with separate feeds for compressed air and that fed from a storage tank Liquor are composed, being in the two feeds to the mixing chamber in each case devices for quantity measurement for the medium in question as well as related Control valves are provided and the foam generated by means of a pipeline to the application device is transported and devices are available for the transport of the web.

Such a device is described in DE-OS 25 23 076 and also the associated working procedure.

The advantages of foaming order liquors are in this DE-OS clearly expressed. In the previously known method, however, the foam placed directly on the goods after it is produced and after it has been as well as application chamber with a rectangular open base area that has a has special training. Placing the foamed liquor directly on the However, goods have significant disadvantages, depending on the physical surface properties and surface differences as well as surface chemical condition and uniformity The foam bubbles differ depending on the chemical application or the content of the goods break quickly and easily and therefore differ per unit area Liquid quantities are available.

The goods or the material web are thus foamed when directly applied Liquor colored unevenly or treated unevenly by the foamed liquor.

The foam provided with colored particles or other additives should Only transport liquid in minimal quantities and this liquid completely release evenly to the material. Since textile materials are never even, direct deposition of foam on such materials always has the disadvantage connected that by different foam destruction over the surface of the textile Different amounts of liquid act on these surfaces across the material.

In the textile finishing, fleet orders may not exceed 1 to 5% deviate from the amount of liquor to be applied per unit of area. This result cannot be achieved by placing foam directly on the material.

The present invention is therefore based on the object of a To achieve equalization of the order of the fleet in foamed form and to precisely determine the amount of liquor to be applied.

The inventive method thus consists in that the foam through a sieve or a sieve-like intermediate carrier onto the textile fabric is applied.

When applied through the sieve or through the sieve-like intermediate carrier then a liquid or liquor accumulation occurs due to the bursting of the foam bubbles, which is completely even over the entire surface. The fleet order can thus in the desired tolerance limit of 1 to 5% of the desired to be applied The amount of liquor per unit area remains. This result is with direct hang-up of foam on the material cannot be achieved and is a major advantage of the Subject of the invention.

Furthermore, there is a further development of the method according to the invention characterized by, a) that a sieve or sieve-like intermediate carrier on the web is placed on which the foam in a sieve or sieve-like intermediate carrier open space is deposited and, b) that the foam is sucked into the goods.

The advantage lies in the application of the foam through suction by means of a vacuum in that the liquid or liquor accumulation is then complete is evenly sucked into the goods over the entire surface.

The liquor application remains within the desired tolerance range.

There is also the option of changing the strength of the Vacuum both the liquid and liquor accumulation above the sieve area to control, as well as the suction depth. Also the amount of consumption of the fleet can be controlled by the adjustable vacuum.

The foam is destroyed when applied over the sieve and on the goods then only the minimum amount of liquid is available, evenly over the entire surface and thus also reaches the goods evenly.

The term evenly "is not to be understood in a restrictive way, rather than a template for a sieve with uniform passage cross-sections can be taken, which can have closed and open surfaces according to the pattern. Here, too, an even application is guaranteed, evenly but according to the sample.

Another advantage of using vacuum is that the penetration of pure liquid into the goods is easier and more even, as if additional mechanical resistance on the surface of the goods was overcome Need to become.

The vacuum, which is controllable in its strength, removes the air made of the material and thus enables resistance-free, even penetration the liquor into the material.

Another idea of the method according to the invention is that, in addition, a mechanical pressing, pressing or squeegeeing of the foam takes place what is the sucking through or sucking in of the foam in the goods in the direction of movement of the goods is subordinate. This has the advantage that any bubbles that have not burst can burst to bring and the sieve or the sieve-like intermediate carrier of foam residues and To clean up or to free the remnants of the fleet.

The device for carrying out the method according to the invention consists in that a sieve or a sieve-like intermediate carrier on the web as perforated sheet metal, as latticework, network, wire mesh, as a sieve drum, Template or the like. trained and possibly dragged along with the goods and driven separately is arranged.

In particular, it is thought of templates that the fleet according to pattern can apply, preferably rotating stencils. But it can also be a network made of plastic or, for example, synthetic fibers and the like, a wire mesh etc. The sieves or sieve-like intermediate carriers bring the bubbles of the foam to burst, thus enable a liquor accumulation in the area of the sieve and of the sieve-like intermediate carrier or on its surface and thus enable one impeccable order on the goods.

Furthermore, the device according to the invention can be characterized in that a) a pipeline above the sieve or the sieve-like intermediate carrier or the like. is arranged, which pressureless the foam into a sieve or sieve-like Subcarrier stores open space and b) a suction device, which in the area the space in which the foam is stored, below the material web or below the material web and a perforated conveyor belt or a sieve drum, over which the web runs, is arranged.

In particular, a continuous working method is intended, it but there is also the possibility of working discontinuously, for example with a flat screen machine.

In addition, the device according to the invention can be characterized in that an application device, such as squeegee, application roller or the like., The Is downstream suction device. This application device can do that Pressing in, pressing in or squeegeeing in the, for example, provided with dye Foam take place.

The downstream application element, such as a roller or squeegee, carries After sucking through the material, the liquor is applied again, causing frosting Free, gray haze-free color image is created. This means that even the top Fiber particles of the goods or the surface of the material soaked evenly with liquor are. If it is only sucked through, this could be caused by a poor device setting Liquor is sucked from the surface of the goods, causing the outermost ends the surface of the goods can then be fleet-free or fleet-reduced, which leads to considerable Quality degradation leads.

With regard to the composition of the foam, each in the textile Equipment used are foamed, for example a dye liquor, a textile finishing liquor, fixing chemicals can be foamed for example applied evenly to the material web by a printing process should be used to prevent the prints from flowing. Essentially is to the Application of foamed dye liquors intended for textile goods and also foamed ones Printing liquors or pastes, for example to apply patterns using stencils to apply textile pile fabric. In certain cases, e.g.

templates can also be used for solid-color dyeing or for fixing which are then not patterned, but in this case act as a sieve.

When foaming textile finishing liquors can be used as foaming material Chemicals are taken, such as those used in industry, for example, which produce cleaning fluids, cleaning powders and the like. So can everyone Materials that dissolve in liquids, are foamed and on material webs are applied by means of the method according to the invention, so that the most varied Effects are achievable.

In the drawings are exemplary embodiments for the invention Device shown. 1 shows the schematic side view of a Printing station of a screen printing machine, Fig. 2 shows an embodiment with a screen-like Intermediate carrier, Fig. 3 shows an embodiment of a printing unit of a screen printing machine with vacuum arrangement and downstream application device.

FIG. 4 shows a further exemplary embodiment, FIG. 5 shows an example of one Liquor foaming device.

All devices shown are used for uniform application from liquid treatment liquors to textile fabrics, preferably webs 1, the supply of the liquor to the device in foamed form of the same he follows. The feeding device is denoted by 2 in the drawings as feeding device A pipeline can be provided with an outflow nozzle 20 extending across the width the web are arranged evenly distributed.

The device for foaming the liquor under pressure is shown in Fig. 5 and consists essentially of a mixing chamber with separate feeds for compressed air and liquor fed from a storage tank and will be described later.

A printing device as shown schematically in FIGS is shown with its design in DE-PS 2,258,892, for example and described.

This is just one possible example of the realization.

In this exemplary embodiment, the material web 1 can be air-permeable on an air-permeable basis Rest on the printing blanket 3, which can be designed so as to be endless, as in FIG. 2 is shown. It is also possible to use a sieve drum to run the web of material 30 to run as shown in FIG.

On the textile fabric, preferably the air-permeable one Web 1, according to the invention, is a sieve or a sieve-like intermediate carrier 4. This sieve can be used as a perforated sheet metal, as a grid, as a network, as a wire mesh, as a sieve drum, as a template or the like. be designed, it can optionally be separately are driven, as the template 4 shown in Fig. 1 or with the goods be dragged along, as shown in FIG. This sieve-like intermediate carrier can also circulate continuously. This continuous circulation is the case with tape stencils according to FIGS. 1 and 3, as is the case with round stencils according to FIG. 4.

It is also shown that the foamed liquor or the foam stored without pressure in a space open to the sieve or sieve-like intermediate carrier will. In Fig. 2 it is shown that this space 50 is not limited. Fig. 1 shows a limited space. The limitation can be made by a wall or a box 5.

Below the space open to the sieve or sieve-like intermediate carrier 4 50 according to the invention a suction device 6 is arranged, which is known per se is, for example, by FR-PS 984 151. The suction device can be moved be arranged or stationary.

You will be movably arranged if the sieve or the sieve-like Intermediate carrier 4 is stationary or when it is in the opposite direction to the sieve or sieve-like Intermediate carrier 4 is supposed to work, but it will be adjustable in its placement work stationary or only be moved back and forth slightly if continuously is operated as shown in the preferred embodiments. the Suction device 6 is connected to a vacuum pump 60. The small, in its strength controllable vacuum removes the air from the material, namely from the textile fabric, such as web 1 and thus enables a resistance-free, even penetration of the liquor into the material.

A pile material is shown in each case, because here the special ones Advantages of the method according to the invention are also particularly effective. the Suction device can be an area-spanning box, it can also be with Be provided through-suction slot 61, which extends over the working width.

The sieve or the sieve-like intermediate carrier 4 can with the pattern closed or open areas, as is common in screen printing. 1 shows a band template which is guided over rollers 10, 11 and 12 is what is previously known.

A scanning device 7, also known per se, can Determine the foam height and is electrical with the control device of the machine tied together. The consumption can be regulated as a scanning device known per se 7 is arranged, which is electrically connected to the foaming device of the fleet tied together is or with a computer with digital display, possibly a process computer, etc., which will be described later.

In Fig. 1, the drive of the printing unit is shown schematically, namely a motor 14 and gear 15. The drive for the web, the air-permeable Printing blanket or the like., The screen or the screen-like intermediate carrier 4 can be somewhere in the device are centrally located, separate drives can be provided, depending according to construction.

Fig. 2 shows a device with a sieve-like intermediate carrier 4 works, which is guided concurrently with the web 1 and possibly rolled up separately is on a roll 40. Here an endlessly revolving blanket 3 is shown, the is air-permeable, just like the web 1 and a suction device 6, which is adjustable in relation to the space 50 below the feeding device 2. The drive of the device is again shown schematically with motor 14 and Gearbox 15.

FIG. 3 shows an exemplary embodiment which corresponds to FIG. 1. here an application element is connected downstream of the suction device 6 in the working direction arranged as an application device 62, which in this embodiment is an application roll is trained.

The space 50 is bounded here towards the rear by a wall 51. In this example, a scanning device 7 is also shown. As an order role An application device 62 operating in the manner of a doctor blade can be driven by a motor 63 and transmission 64. Another application device 4 known per se can be used in FIG Suction device 6 are connected downstream.

Fig. 4 shows an embodiment with a round template as a sieve. As in the other exemplary embodiments, this can also be closed according to the pattern or open areas. It is also possible to use this screen printing stencil or to perforate the sieve 4 evenly. Into the inside of this screen printing stencil is again a feed device 2, such as a pipeline, drawn that the stores foamed liquor in pressureless form in an open space 50. Internally a sieve drum 30, which can rotate according to the working direction, and with a drive, for example from motor 31 and gear 32, can be provided the suction device 6, which has already been described.

Between the template and the sieve drum 30, the web runs in the specified manner Direction of arrow. The guide means are indicated by rollers 17 and 18. Here is again an application device 62 connected downstream, namely a squeegee, shown as a squeegee, which is also adjustable. A scanning device 7 can also be arranged here to the foam wedge in front of the doctor blade or the application device 62 to be scanned and limited in height.

In Fig. 5 is a possible embodiment of the device for Foaming of the liquor 8 is shown. The fleet is fed in from one Reservoir 80 and the supply of compressed air, for example from a Compressor 81 off, with devices for quantity measurement in both supply lines 180 and 181 280 and 281 are provided. In addition, related control valves are provided, Of which the control valve 82 is shown only in the compressed air line 181.

A pump 83, driven by the motor 183 via gear 283, is the liquor thus from the storage container 80 via the supply line 180 to a Mixing head 84 guided with mixing chamber 184. The compressed air is in this embodiment brought into an annular space 284 of the mixing head 84 and comes from below through openings into the mixing chamber 184, in which glass balls or granules or the like. are located can. Via a line 85, a pipe, a hose or the like. The produced Foam into the feed device 2. In the compressed air line 181, a main tap 86 may be provided.

The entire device can be connected to, for example a computer 9 or to a process computer, possibly with a digital display 90, where all values can be fed in and offset against each other, namely from the scanning device 7 with regard to the limitation of the foam application in the open space 50 from the main drive of the machine 100 or instead from the individual Driving devices of the respectively rotating and moving parts for the movement the material web 1, for the air-permeable printing blanket 3 or the screen 4 or the stencil, for the application device if it is designed as a squeegee roller, for example is. Furthermore, the process computer 9 or the like. with the suction pump 60 electrically be connected and with the entire device for foaming 8 in the individual stations, for example motor 183, control valve 82 and the devices for quantity measurement 281 and 280, as well as, for example, with the main tap 86. This means that the amount of Adjustable foam feed. The speed of production can also be adjusted as well as the vacuum in its strength.

The process computer works as an automatic control device, so that when changing one parameter the others, automatically in the same relation be adjusted.

The level of the deposited foam can be kept constant and the level height can be set in the room inside, for example a template, can be changed by a corresponding setting of the scanning device 7. In addition there is the possibility that the produced or the device supplied Foam exactly corresponds to consumption.

In particular, all information and features disclosed in the documents the disclosed spatial configurations, insofar as they are used individually or in combination are new compared to the prior art, claimed as essential to the invention.

Further characteristics and features of the invention emerge from the given as an example, advantageous embodiments described above.

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Claims (14)

Claims 1. A method for the uniform application of liquid Treatment liquors on textile fabrics, the supply of the liquor to Device in foamed form of the same takes place, with a device for foaming the liquor under pressure from a mixing chamber designed as a foam generator with separate feeds for compressed air and that fed from a storage tank Liquor are composed, being in the two feeds to the mixing chamber in each case devices for quantity measurement for the medium in question as well as related Control valves are provided and the foam generated by means of a pipeline to the application device is transported and devices are available for the transport of the material web, d a d u r c h characterized that the foam through a sieve or sieve-like intermediate carrier (4) is applied through to the textile fabric. 2. The method according to claim 1, characterized by, a) that on the Material web a sieve or sieve-like intermediate carrier is placed on which the Foam is deposited in a space open to the sieve or sieve-like intermediate carrier and b) that the foam is sucked into the goods. 3. The method according to claim 2, characterized in that the foam stored without pressure in the open space on the sieve or sieve-like intermediate carrier will. 4. The method according to claim 1 and 2, characterized in that in addition the foam is mechanically pressed in, pressed in or squeegeed, what is subordinate to the through-eye or sucking-in of the foam in the direction of movement of the goods. 5. Apparatus for performing the method according to claim 1, characterized characterized in that on the web (1) a sieve or a sieve-like intermediate carrier (4) as perforated sheet metal, as latticework, network, wire mesh, as a sieve drum, Template or the like. trained and possibly pulled along with the goods or driven separately is arranged. 6. Apparatus according to claim 5, characterized in that a) over the sieve or the sieve-like intermediate carrier (4) a feed device (2), like pipeline or the like. is arranged, which pressureless the foam into a sieve or sieve-like Intermediate carrier (4) stores open space (50) and b) a suction device (6), which in the area of the space (50) in which the foam is deposited below the web (1) or below the web (1) in a perforated conveyor belt, such as printing blanket (3) or a sieve drum over which the material web (1) runs, arranged is. 7. Apparatus according to claim 5 and 6, characterized in that an application device (62), such as a doctor blade, application roller or the like., The suction device is subordinate. 8. Apparatus according to claim 5, characterized in that the foam feed device (2) is connected to a controllable control device, according to which the amount of is actuated in the work process spent foam. 9. Device according to claim 5 and one of the following claims, characterized in that the in the space (50) on the sieve or sieve-like carrier (4) deposited foam held at its level by a scanning device (7) which acts on the feed pump (83,183,283) via control elements. 10. Apparatus according to claim 5 and 9, characterized in that the scanning device (7) or the like. is height adjustable to change the level height of the introduced foam. 11. The device according to claim 6, characterized in that the suction device (6) Connected to a device for adjusting and changing the strength of the vacuum, preferably with an adjustable and controllable vacuum pump (60). 12. The device according to claim 6, characterized in that the suction device (6) is adjustable in relation to the open space (50). 13. Apparatus according to claim 5, characterized in that the sieve or the sieve-like intermediate carrier (4) is continuously circulating. 14. The device according to claim 5 and one of the following claims, characterized in that a process computer or computer with digital display or the like. is provided in the various parameters of the work process can be fed in and from which the various parameters can be influenced, with the process computer or computer is used as an automatic control device.