EP0082466A1 - Method and apparatus for coating with foam - Google Patents

Abstract

Different liquors are each foamed separately from one another and these foams are brought together in a continuously or discontinuously controlled manner. This mixture or mixture consisting of differently colored or chemically different foams and / or differently composed foams is fed to a foam application device in which the different foam mixtures or foam mixtures are applied as corresponding colors or color effects to a preferably continuously running fabric web. An application mixture or an order mixture is achieved in a merging area of the individual foams, with another merging or quantity area in which a finer batch or mixture is produced can be connected downstream of this merging area. The intimate mixing of the different liquors can be desired or prevented, for example by using different thickeners or different chemicals.

Description

The invention relates to a method and a device for applying foamed liquor through a sieve or a stencil.

Such devices are known per se. For example, a method and a device for forming foam and for applying foam are known from DE-OS 25 23 062. With this device, only a single foamed liquor can be applied directly to a product, namely as foam. The disadvantage of this device is that there is only a single foam generator, which consequently can foam only a single liquor, apart from the fact that the foam is applied directly to the goods and it is extremely difficult to destroy this foam evenly on the goods .

Furthermore, the application of liquor through a sieve or through a stencil is known from DE-PS 20 26 492.

Furthermore, a device is already known in which a dye liquor is produced in a foam generator and is applied to the goods through a sieve or a stencil.

Furthermore, it is known from DE-AS 22 14 377 to achieve multicolor effects directly on the goods by applying miscible and immiscible foams.

With all these devices, however, it is not possible to achieve precisely reproducible color applications on a web, and indeed with a single application station, the choice of color, the pattern, its repeat accuracy or its repeat freedom being freely selectable.

There are already known application devices with which patterns can be achieved, in that e.g. different colors are sprayed onto the goods as fleets from nozzles, these nozzles staining the goods according to the pattern. However, clear patterns cannot be achieved if the nozzle is brought so close to the goods. When the paint is sprayed out of the nozzles, this happens in an uncontrolled manner. In addition, there is a relatively strong impregnation of the material web by the dyes, since both the central area that is hit by the nozzle and the edge area of the application cone of a nozzle must be sufficiently colored.

Most printing or application methods and devices have the disadvantage that precisely delimited areas appear in the end product, which are constantly repeated in a very exact repeat, so that, for example, when printing on carpeting or carpets, the collation of individual pieces is difficult for the end user. You have to pay close attention to the pattern, so that cut positions on the carpet are not clearly visible. This problem has also been seen several times and tried to solve.

On the other hand, it is always difficult to recreate a specific color. The individual layers often differ in color and quality.

The present invention is therefore based on the object of providing a method and a device with which, by the application of foamed fleets, it is possible to achieve color applications which can be determined in advance and which are reproducible at any time, and patterns, namely multi-color patterns, can already be produced by a single application station, which are reproducible, but not necessarily linked to a repeat.

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

With the invention it is now possible, for example, to initially produce foams in the three basic colors, to combine them in a measured manner and to either mix or mix them in precisely predetermined quantities in order to either obtain a very specific basic tone or to obtain a mixture which enables multi-color application.

The advantage of the rate measurement after foaming of the liquor is in the greater accuracy of the measurement and thus to be achieved in the color mixture, or in the color to be achieved ^g emenge.

• Bei einem Mischungsverhältnis von 1 : 300 beim Aufschäumen der Flotte mittels Druckluft und damit einer Vergrösserung des Volumens um das 300-fache verringert sich die Fehlerquelle um 1/300 bei der Messung des Schaumes im Verhältnis zur Mengenmessung bei der nicht verschäumten Flotte. Dies ist ein erheblicher Vorteil gegenüber vorbekannten Flottenmischungen zur Herstellung von flüssigen Auftragsflotten, die nicht verschäumt werden.

This should be illustrated using an example:

• With a mixing ratio of 1: 300 when foaming the liquor using compressed air and thus increasing the volume by 300 times, the source of error is reduced by 1/300 when measuring the foam in relation to the quantity measurement in the non-foamed liquor. This is a significant advantage over vorbe knew fleet mixtures for the production of liquid order fleets that are not foamed.

If the foamed and precisely predetermined liquors are not mixed with one another, but only mixed according to a preferred exemplary embodiment according to claim 5 of the invention, it is possible to first divide different liquors or liquids into supply quanta or to supply them in small quantities to a merging device, a whole in this merging area certain mixture arises. This batch has absolutely precisely defined fleet components from different foam generators. The mixture is then not mixed intimately, but practically consists of a coarse mixture and the foams are only combined. You then reach the order area and are applied to the goods via the sieve or stencil, where they are returned to the liquor state as they pass through the sieve or stencil. Multicolor effect is created on the goods due to the fleet quantities or when using the same color with differently composed foams there are color nuances.

The application can be carried out with all possible application devices, for example by knife-coating the foam, with the aid of suction devices and the like. A sieve or a template is interposed.

The device for performing the method is specified in the features of claim 14.

It is essential that the individual foams are foamed separately from one another and either are mixed together, for example, from three basic colors to form any reproducible mixed color, or remain partially separate from one another, so that when applied to the goods through the stencil or the sieve, the surface the goods are soaked with different fleets. If a patterned template is interposed, only partial areas are soaked accordingly, which in turn can also have different color spots.

The different foams, which are supplied to the application device can be in different colors and / or different compositions ^g estellte foams that provide eg only shades.

Known foam generators can be used as foam generators, for example a foam generator according to DE-OS 25 23 062, which is considered a static foam generator. Dynamic foam generators are also known, for example from US Pat. No. 4,193,762. In general, a fleet containing surfactants is pressed through a pipeline into a mixing chamber by applying a constant superatmospheric air pressure which can be regulated, for example of about 2 bar . Both the amount of liquor supplied and the amount of air supplied can be set and regulated. There are different versions of mixing chambers.

A simple container can be present as the merging device, into which the supplied foams from a selected or existing number of foam generators can be introduced and stored, whereby they can easily pass through this merging device. But you can also in this Zusammenführun ^g multiplexing frame generating apparatus roughly mixed or even mixed. It is essential that the foams are fed partially separated from each other and, if necessary, mixed and then carried on or remain partially separated from one another if a mixed-color application is not desired, but a multi-color application.

Annealing can take place by means of known blending devices if the merging alone is not sufficient. In order to ensure that the supplied foams are cut up before and / or in the merging area, there is the possibility of arranging adjustable, controllable valves in the conveyor device for the foams, preferably the lines. These valves can be program-controlled, which is not shown in more detail.

Another idea of the invention is that a merging head is connected downstream of the merging area, it being possible to achieve a remixing of the merged foams in this ming head, possibly also remixing, but preferably, if a multi-color application is desired, a slow-speed coarse agitator .

Another idea is that a foam store is arranged between the foam generators and the merging device, into each of which the foam generator conveys. It is extremely difficult to switch off foam generators in the meantime, since they each take a few minutes to produce stable foam. In the case of a downstream foam accumulator, the foam generators can continuously fill the foam accumulator and the downstream, likewise program-controlled valves open and close, the foam accumulated in the respective foam accumulator relaxing during the opening hours and flowing to the merging device. The inflow to the merging device is thus divided, that is, fractionated, so that there is a mixed foam in the application device, that is to say the customer, if uni is to be colored with a certain color or a mixed foam is present, but with which, since none intimate mixing was carried out, a multi-color application or the achievement of color effects is possible.

Further characteristics and features result from the exemplary embodiments described below.

• Fig. 1 eine Vorrichtung zur Aufbringung einer Uni-Farbe,
• Fig. 2 eine Vorrichtung zur Herstellung von Farbeffekten.

Two embodiments of the invention are explained with reference to FIGS. 1 and 2. Both figures show schematic representations of devices, namely

• 1 shows a device for applying a solid color,
• Fig. 2 shows a device for producing color effects.

As seen from Fig. 1, are preferably three arbitrarily designed, provided in a known foam generator 1, which may also be referred as a foam enerator ^g. This foam generator 1 have a separate feed fleet 2, and a separate, also regular and controllable _D ruck air feed 3. The control devices 20 and 30 for supplying the liquor and for the supply of compressed air are shown only symbolically. They are drawn as manual valves, but should be controllable from a computer. The fleet storage container is also only shown symbolically.

Lines 4 lead to foam stores 5, which are advantageous in order to ensure a uniform supply of the foam to the application device.

Flow control devices 6, namely flow meters or sensors, in which preselected amounts of foam are measured and fed to a merging device 7 via the inflow lines 4a are arranged downstream of the foam stores 5. In the embodiment of FIG. 1, it is a mixing device. After an intimate mixing in the arbitrarily designed merging device 7 of the exemplary embodiment in FIG. 1, the foam is fed via one or more feed lines 4b to a foam application device 8, for example a slot doctor blade or a device which places the foam in front of a doctor blade, this application device 8 inside a Siebzy Linders 80 is arranged. A screen can also be provided below the application device, as is known in screen printing machines. The foam liquefies as it passes through the sieve and is applied to a product 9 in a pattern or in uni. The goods 9 can be transported in the direction of arrow A.

It can be any sieve, sieve belt, sieve cylinder or ^g . act, for example also about a screen belt which is guided around rollers according to DE-PS 22 58 892. The application device can also be a doctor roller according to DE-OS 20 35 220.

Any foam generator known in the art can be used as the foam generator 1.

Simple containers can be provided as the foam store, which have a shape that is favorable in terms of flow technology, so that no old foam remains in these containers.

Devices can be provided as a flow meter or transmitter or as a flow control device 6, which are known for measuring the flow rate in fleets. These devices preferably have two functions, namely on the one hand to control the flow rate and practically limit the amount of foam that reaches the mixing device, and on the other hand, if the foam generator delivers too much or too little, the corresponding foam generator is adjusted down or up accordingly, i.e. to influence in its production. The degree of foaming generally ranges between 1: 4 to 1: 300 and in this range the error of the respective color feed into the mixing device or mixing device, which is referred to as the merging device 7, is reduced.

With a degree of foaming of 1: 300, i.e. a mixture ratio of liquor and air in a ratio of 1: 300 and an increase in volume by 300 times, the source of error is thus reduced by 1f300 when measuring the foam in the flow control devices 6, which as Flow meters or transducers are designed.

The setting of the flow meters or transducers takes place from a computer, which is denoted by 60 in the drawing and which can be electrically connected to the flow meters or transducers or the flow control devices 6.

A device is thus created with which a predetermined color mixture for a foam application can be achieved. For example, any percentage of red, any percentage of yellow and any percentage of blue can be released by the flow control devices 6 and reach the merging device 7, in this case a mixing device, where they are thoroughly mixed and applied by the foam applicator.

As already mentioned, the foam application device can be of any design, combined with a suction box and doctor blade, a screen printing device known per se, a device which runs with a uniformly perforated, possibly continuously rotating screen or the like. Depending on which effect is finally achieved is to be, namely, whether the goods are to be dyed, to be printed according to the pattern, etc.., a corresponding foam application device is set ^e-g a.

As goods, any web can be dyed or printed in this way, but also strands, threads, fibers, strands and the like. Even flat individual pieces can be provided with a foam application.

A fiber structure can serve as material, such as textiles, nonwovens, non-woven, but also paper, plastic, foils and the like.

With the device according to the invention according to FIG. 1, it is possible to determine the percentage of the desired color of the foam to be applied, to determine if necessary and to use these values in such a way that they determine the flow rates per unit time for the primary colors. A specific color tone can therefore first be fed into the computer, the values of which are then fixed and then the flow control devices 6, preferably the flow meters, can be set accordingly, which in turn may influence the respectively assigned foam generator 1. This can be repeated any number of times.

The principle of the present device of FIG. 1 is therefore to make color mixtures precisely determinable and reproducible in advance by creating foam from basic color liquors.

In order to ensure the inflow to the foam application device, it is advantageous to set the foam generator 1 in such a way that a higher pressure prevails in the foam stores 5 than in the area of the foam application device. This ensures that the foam flows in evenly.

In Fig. 2, a device is shown with which a color-spot-like application is made possible. If a stencil 80 is selected which applies a pattern, each pattern in the stencil can in turn have different areas of color spots.

The basic structure of the device is the same as that shown in FIG. 1. The same reference numerals indicate the same devices.

The foam is again fed to a merging device 7 via conveying devices of the foam, for example pipes or hoses 4, 4a, this merging device absorbing the supplied amounts of foam. The amounts of foam are clearly separated from each other. One can merge this device 7 ^g ung call Grobvermen. It can be a simple case. However, there is also the possibility of arranging carefully working mixing units in this merging device 7, which merely mix the supplied foam strands together somewhat.

However, there is also the possibility of simply designing the merging device 7 as a container.

A fine quantity head 70 can be arranged downstream of this merging device 7, in which e.g. a slow and careful agitator is arranged.

In the exemplary embodiment shown, foam stores 5 are again provided between foam generator 1 and merging device 7, each of which has flow control devices 6 connected downstream. These can be designed as valves. These valves can be program controlled. This makes it possible for the foam generator 1 to continuously produce and convey foam with an average value, the flow control devices 6 or valves releasing the foam in defined time units or in controlled time units when it is to get into the merging device 7. This is done via lines 4a.

In this very coarsely merged consistency or coarsely mixed or finely mixed form, the foam comes from the merging device 7 or the fine quantity head 70 into a line, a tube or hose 4b, which leads to an order device 8. In this application device 8, the foam is applied to a product 9, for example to a product web running in the direction of arrow A.

As goods, in turn, fiber structures, textiles, non-woven, paper or the like. Find use, in web or piece form.

Each foam generator 1 or the like takes out of its storage container 21. its fleet on and via the compressed air line 3 compressed air is also supplied in precise dimensions and the foaming begins in a manner known per se. Both media that flow to the foam generator 1. are steplessly controllable and repeatable.

For example, 1 foam in the colors yellow, red, green and blue runs out of the foam generator. On the one hand, these foams can be produced from liquids or liquors with different consistencies, and on the other hand, as already mentioned, may also be provided with different colors. In the illustrated embodiment ⁼ example, completely unmixed, absolutely separate color foams or foam consistencies appear in the lines 4, in the foam stores 5 and in the lines 4a. A mixture of foams then results in the merging device, so that all four colors are then present in clear lines in the foam strand in line 4b in the example shown.

If you set the first valve, i.e. the first flow control device 6, with a short switching sequence, the second valve in such a way that it opens in each case over longer periods of time, and the valves of the last two lines open and close in a program-controlled manner, the result is obtained in the merging device 7, i.e. in the quantity range, very specific quanta of colored foam or from below different foam consistencies and then achieves a desired specific pattern on the goods 9 by the application device 8. This pattern is not accurate when the template 80 is designed as a sieve and is not patterned. However, it can be reproduced in a pattern-like manner and, in the case of patterned stencils, the individual color spots in the application areas are patterned, namely reproducibly patterned.

If one of the valves or flow control devices 6 remains open at all times, a uniform color base tone with relatively large proportions of this particular color or this particular foam can be supplied to the application device 8.

In addition, the foaming can be done differently in that more or less compressed air is fed through the lines .3 to the foam generator 1. This enables different bubble sizes to be achieved. Due to different bubble sizes, intimate mixing of the foams in the merging area 7 can in turn be avoided if this is not desired.

Furthermore, it is possible to use different liquids for the production of the foams if they are to be given the same or different colors.

The consistency of these different liquids can be such that they do not mix too easily, especially if they are foamed. The liquors can be different in their consistency, for example in that they are differently viscous or contain different thickeners.

There is also the possibility that the liquors to be foamed can be reacted with different reactants, e.g. Thickeners are set or have an anionic or cationic effect.

There is also the possibility of supplying the foam liquor portions to the merging device 7 with different delivery volumes. For example, nothing can take place in the merging device 7 other than the continuation of the foam parts or particles arriving with different delivery volumes. It is also possible to mix these fractions; the foam fleets still crude to continue to achieve a change in the pattern aufzutra ^g. This can be done through the batch, through obstacles such as shovels, wires, sieves or the like. take place or by slowly rotating agitators of known type.

There is also the possibility of having all valves or flow control devices 6 work in a program-controlled manner. It is possible to temporarily switch off one of the colors or one of the chemicals, switch on another for this and the like.

This also allows a gradual change in the pattern, for example a gradual shift from lighter tones to darker tones and then again a shift back to lighter tones, as desired.

The fraction proportions of the foams supplied can again be set differently. In this way, the foam can reach the merging device 7 in small batches from the first color, in larger batches from the second color and continuously from the third color.

Basically, the achievement of color effects is desired, whereby these can be monochrome color effects by choosing e.g. different thickeners for the same color. However, multi-color effects can also be achieved on the goods.

As already mentioned, the idea of the invention is not limited to the exemplary embodiment shown. Variations are conceivable and possible. The term "color" should not be understood as restrictive. Other chemicals that can be foamed to create a patterning effect can also be applied, e.g. Brightener, etchant and the like

In any case, an intimate mixture of the supplied foams should not be achieved in the merging area 7 and also in the fine mixing head 70 in the exemplary embodiment in FIG. 2, but the foam proportions are only mixed to such an extent that, for example, for a multi-color foam application, each color remains absolutely separate, namely in smaller or larger foam fractions or foam fractions.

The features and combinations disclosed, insofar as they are new compared to the prior art, are regarded as essential to the invention, in particular the advantageous embodiments which are characterized in the subclaims.

Claims (16)

1. A method for applying foamed liquor through a sieve or a stencil, characterized in that the color-different liquors are each foamed separately from one another and the foams are brought together in predetermined, measured or measured quantities and in the achieved state on the goods through the sieve or the template can be applied through. 2. The method according to claim 1, characterized in that the different color fleets, which are foamed separately from one another, are continuously merged and mixed in predetermined and measured quantities and are mixed in a mixed state in the new, uniform color obtained on a product. 3. The method according to claim 1 and 2, characterized in that the percentages of the desired color of the foam to be applied are determined and these values determine the flow rates to the mixing area per unit time for the primary colors. 4. The method according to claim 1, characterized in that the separately produced, differently colored foams are brought together continuously or discontinuously controlled and fed as differently composed foams as a batch to the foam application area in which the different Amounts of foam are applied as corresponding color effects of different colors and / or shades. 5. The method according to claim 4, characterized in that the merging area of the individual foams to achieve the order mix is followed by a further mixing area in which a finer mixture is generated to achieve finer color effects when the foam is applied. 6. The method according to claim 4, characterized in that the supplied foams are cut up before and / or in the merging area. 7. The method according to claim 4 and one of the following claims, characterized in that the liquors to be foamed are different in their consistency, how different viscous or different thickeners are, or are anionic or cationic. 8. The method according to claim 4 and one of the following claims, characterized in that the foam liquor portions are supplied to the merging area with different delivery volume or fractionated. 9. A device for performing the method according to claim 1, characterized in that a number of foam generators (1) with separate liquor feed (2) is arranged upstream of a merging device (7) to which the foam generators (1) lines (4) are guided with flow control devices (6) and the merging device (7) is connected to a foam application device which is provided with a sieve or a template (80). 10. The device according to claim 9, characterized in that the lines (4) with flow meters or transducers as flow control devices (6) are provided. 11. The device according to claim 9, characterized in that the flow control device (6) as a transmitter with the respective foam generator (1) for control, preferably electrically, are connected. 12. Apparatus according to claim 9, characterized in that between the Schaumerzeu he ^g (1) and the flow meter or transmitter or the Durchflußkontrollvorrichtung (6) a foam memory (5) is arranged. 13. The apparatus according to claim 9, characterized in that the flow meter or flow control devices (6) or transducers are electrically connected to a computer (60). 14. The apparatus according to claim 9, characterized in that of the merging device (7), a manifold (4b) or the like. is guided to an application device (8) provided with a sieve or template (80). 15. The apparatus according to claim 9, characterized in that the lines (4a) are arranged as a flow control device (6) adjustable, preferably program-controlled valves in the conveyor. 16. The apparatus according to claim 9, characterized in that the merging device (7) a quantity or Nachmengkopf (70) downstream and / or between the foam generators (1) and the merging device (7) a foam storage (5) is arranged in which a foam generator (1) promotes.

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