EP0226687B1 - Method for printing sheet-like material - Google Patents

Description

The present invention relates to a process for embellishing by dyeing fabrics such as fabrics, knits, nonwovens or similar articles in the form of a breathable sheet; it also relates to a device allowing the implementation of this process.

To date, in addition to the actual dyeing processes, numerous techniques are used to embellish a fabric by coloring.

The oldest, still used today, is to decorate the fabrics by hand. This technique makes it possible to carry out any decor but is of immense complexity and proves unsuitable for reproduction in large series.

In order to reproduce the unique work in all its subtlety and to allow its reproduction as quickly as possible, various printing techniques have been proposed.

• - l'impression dite "à la Lyonnaise", qui nécessite pour sa mise en oeuvre une matière colorante visqueuse, un écran (toile de fin tissage) servant de pochoir, un racle permettant de faire passer la matière colorante au travers du pochoir pour la déposer sur l'étoffe à décorer;
• - l'impression dite "par transfert", technique selon laquelle la matière colorante est préalablement appliquée sur un papier support et est ensuite transférée sur l'étoffe par l'intermédiaire de la chaleur.

Among these techniques, we can cite:

• - the printing known as "à la Lyonnaise", which requires for its implementation a viscous coloring matter, a screen (fine weaving canvas) serving as a stencil, a doctor blade allowing the coloring matter to pass through the stencil for the place on the fabric to be decorated;
• - so-called "transfer" printing, a technique according to which the coloring matter is previously applied to a backing paper and is then transferred to the fabric by means of heat.

For the implementation of these techniques, it is necessary to take into account two factors obviously having little compatibility, namely, on the one hand, the capillarity which results from the very nature of the product to be printed and, on the other hand, the fluidity of the coloring matter which must be controlled so that it can be applied properly on the fabric to be embellished.

To date, to obtain control of the dye, the most commonly used solution consists of using a thickener.

FR-A-2 319 433 has also been proposed (as well as to a certain extent in FR-A-2 420 432) embellishment methods by coloring fabrics or similar products which consist in laying flat the article to be embellished, subjected to a suction and to project the dye against the surface by means of nozzles. In these techniques, the dye is delivered in the form of liquid jets or in the form of spraying. These two processes have the particularity of wetting the fabric and at the same time requiring drying. In the case of the jet, the nozzle is as close as possible to the fabric and the printing dispenses with stencil. In the case of spraying, a stencil is used which allows only finely drawn drawings on thick supports (carpet), this because of the propensity that a liquid has to fuse.

DE-A-2 932 124 describes a device using a dye dispensing head by means of nozzles, but such a device does not make it possible to obtain colored patterns having extreme finesse, possibly by superimposing several different dyes.

All these techniques require for their implementation specific materials, expensive and delicate to implement and generally making it possible to obtain only a specific type of articles. In addition, very often, the problem arises of drying after deposition of the dye as well as that of cleaning the support on which the articles are kept during printing. Furthermore, in the case where the dye is deposited by means of nozzles, as in FR-A-2 319 433, not only is the fabric wet, and must therefore be dried, but also, it is not it is not possible to obtain large colored surfaces given the proximity of the nozzles to the surface of the fabric.

Now we have found, and this is what is the subject of the present invention, a process of embellishment by dyeing fabrics or similar products which solves these problems and makes it possible to obtain in a simple and economical manner a very large variety of effects, requiring only one and the same installation for its implementation.

• - à mettre à plat l'article à embellir sur une table présentant une zone perméable à l'air, cette zone étant soumise à l'action d'un système d'aspiration;
• - à projeter la matière colorante contre la surface de l'article au moyen d'une ou des buse(s) permettant de projeter le colorant, à l'état liquide, sous forme d'un brouillard de colorant vaporisé ou atomisé, l'aspiration produite sur l'étoffe étant telle qu'elle permet de faire pénétrer à coeur le colorant dans l'étoffe et d'en évacuer l'excédent, ainsi que de le véhiculer dans son parcours à l'air libre entre la sortie de la buse et l'étoffe.

In general, the invention therefore relates to a process of embellishment by coloring of an article formed of fabrics or similar products permeable to air, which consists in a similar manner to that of the document DE -A-2 932 124:

• to lay the article to be embellished flat on a table having an air permeable zone, this zone being subjected to the action of a suction system;
• - spraying the coloring matter against the surface of the article by means of one or more nozzles making it possible to spray the dye, in the liquid state, in the form of a mist of vaporized or atomized dye, the aspiration produced on the fabric being such that it allows the dye to penetrate to the heart and evacuate the excess, as well as to transport it in its course in the open air between the outlet of the nozzle and fabric.

• - on interpose entre l'article et la source de colorant un ou plusieurs écrans ou pochoirs ;
• - le brouillard vaporisé ou atomisé de colorant est réalisé de telle sorte que l'on obtient une fragmentation extrêmement ténue, voire moléculaire dudit colorant, évitant ainsi à ce dernier de mouiller l'étoffe, les particules étant suffisamment petites pour être séchées instantanément lors de leur contact avec l'étoffe ;
• - l'aspiration produite sous l'étoffe est telle qu'elle permet :
  • . de maintenir l'étoffe sur la table lors des différentes phases de son impression et de plaquer le pochoir contre la surface de ladite étoffe ;
  • . de sécher instantanément le colorant lors de son contact avec l'étoffe.

The invention is characterized in that:

• - one or more screens or stencils are interposed between the article and the colorant source;
• - the sprayed or atomized fog of dye is produced in such a way that an extremely fine, even molecular, fragmentation of said dye is obtained, thereby preventing the latter from wetting the fabric, the particles being small enough to be dried instantly during their contact with the fabric;
• - the suction produced under the fabric is such that it allows:
  • . to maintain the fabric on the table during the various stages of its printing and to press the stencil against the surface of said fabric;
  • . to instantly dry the dye when it comes into contact with the fabric.

In other words, in accordance with the method according to the invention, instead of introducing a thickener into the dye, and using it in the liquid state, optionally in the form of a jet obtained by means of a nozzle. , it is vaporized (or atomized) in the form of a mist, that is to say in a state of extremely fine fragmentation, even molecular dyes, which makes it possible to apply it to the fabric, also thanks to the suction produced below the latter, without it diffusing on the surface while penetrating to the core and this, without wetting it significantly, the current of air produced by the suction which also allows said dye mist to be transported and controlled.

Thanks to such a process which does not require the use of a thickener or a deposit in liquid form as is the case when the coloring matter is sprayed, it is therefore possible to remove all the stresses involved the prior techniques, namely inter alia not having to remove the thickener afterwards and waiting for the drying of this product.

Indeed, in the case of the invention, the atomization drying practically instantaneously, it is therefore possible to immediately superimpose the prints while retaining their extreme fineness, while the wet prints lose a large part of the finesse possibilities. The absence of thickener allows absolutely perfect dye overlays; in fact, the thickener of the first impression always more or less screens the next one and thereby prevents transparent repairs. In addition, this instant drying allows the immediate winding of the printed fabric. The stencil makes it possible to obtain complex gradations, to dye solid or gradient fabrics, to obtain stripes and this, in a great complexity of coloring which is impossible to date. Finally, the method according to the invention can be implemented with materials which are difficult to print such as for example knitted fabrics, the treated fabrics being able to be dense or on the contrary very light, for example being in the form of muslin .

When the dye is deposited, the fabric can be kept either fixed or, on the contrary, be moved at a constant speed or not.

Finally, the power of the suction exerted under the fabric during the dye deposition phase will depend on the material to be treated and more particularly on the porosity that it presents. This suction must be adjusted not only to produce a very large vacuum but also to cause a large flow of air through the article. As an indication, the depression will, depending on the article to be printed, be equivalent to ten to a thousand millimeters of water column and must produce an air flow of between 2000 and 5000 m3 per hour.

• - l'aspiration produite sous l'étoffe est telle qu'elle permet :
  • a) de véhiculer le colorant dès sa sortie de buse à coeur de l'étoffe et au travers du pochoir s'il existe,
  • b) de sécher instantanément le colorant lors de son contact avec l'étoffe,
  • c) de plaquer l'étoffe sur la table d'aspiration et de l'y maintenir lors des différentes phases de son impression,
  • d) de plaquer le pochoir, s'il existe, contre l'étoffe,
  • e) d'évacuer l'excédent des colorants ou autres produits atomisés.

The suction will be adjusted to allow, not only to press the fabric on the support and possibly the stencil if it exists, but also to channel the mist of atomized dye on its path between the outlet of the nozzle and the surface of the 'fabric.

• - the suction produced under the fabric is such that it allows:
  • a) to convey the dye as soon as it leaves the nozzle at the heart of the fabric and through the stencil if it exists,
  • b) to instantly dry the dye upon contact with the fabric,
  • c) to place the fabric on the suction table and to keep it there during the different stages of its printing,
  • d) press the stencil, if there is one, against the fabric,
  • e) evacuate the excess of dyes or other atomized products.

Advantageously, in practice, the device according to the invention will have the following characteristics.

The suction table will consist of a watertight box fitted with a suction turbine.

The table top consists of a structure, on the one hand offering the least possible resistance to the passage of air while being, on the other hand, sufficiently resistant to the depression caused under the tissue. The dimensions of this table will depend on the dimensions of the fabric to be treated. In order to be able to process fabrics of different formats, a shutter may be used to delimit the suction surface of the table, the surface left free by said shutter being a function of the dimensions of the decoration to be made.

The suction turbine will have a capacity proportional to the surface of the fabric to be treated and must allow, as said previously, not only to create a strong vacuum below the article but also to cause a large air flow through the article. This flow rate will depend on various parameters, namely in particular the texture or density of the fabric as well as the surface left free by the shutter or the stencil used; this flow rate must be sufficient not only to make the dye penetrate inside the fabric but also to channel the mist of vaporized or atomized dye between the outlet of the nozzles and the surface of the fabric.

Maintaining and positioning the fabric on the table top can be achieved in different ways.

• - soit le tissu est lui-même l'objet de la traction,
• - soit la traction (avance par intermittence ou en continu) est effectuée par l'intermédiaire d'un tapis roulant (constitué d'un tissu genre toile à tamis) sur lequel le tissu sera véhiculé.

So, for example, the fabric can be rolled up on one side to unroll on the other side of the printing table. To do this :

• - either the fabric is itself the object of traction,
• - Either the traction (intermittently or continuously advancing) is carried out by means of a conveyor belt (made up of a fabric like a sieve cloth) on which the fabric will be conveyed.

In the first case, synchronization means allowing the fabric to be moved step by step (photocells, tracking cameras, feelers, clamps between physical stops, etc.) are provided.

In the second case, the synchronization system could be much more mechanical since the treadmill is not subject to any distri- bution.

As a system for distributing dyes by vaporization (or atomization), use will be made, for example, of nozzles of the type known as airbrushes which allow the vaporization of liquid dyes under the effect of compressed air; such airbrushes allow, in accordance with the invention, to form a dye mist by fractionating extremely thin or even molecularly said dye.

These airbrushes can produce variable sprays in density and concentration, either by the diameter of the nozzles used, or by modifying the dye / air parameter.

Generally, such airbrushes include a compressed air line, a dye supply line, an opening and closing valve and a flow control system.

These airbrushes will be used in the form of ramps made up of a set of fixed or removable airbrushes positioned on a support. The outputs of the airbrushes will, in accordance with the invention, be placed at a relatively large distance from the surface of the fabric to be decorated, this distance being at least of the order of five centimeters but advantageously being between ten and fifty centimeters.

These airbrushes are supplied by a compressed air duct, each airbrush being moreover supplied by one or more dye ducts (or of various other products), these ducts being able to be alternately closed or opened by means of a system of suitable valves, to allow an instant change of colors or products. The arrival of cleaning products from a purge and air intake system facilitates the various operations necessary for their simultaneity. The various controls for air intake, opening, closing of airbrushes, permutation of dyes or products, opening and closing of solenoid valves, can be carried out either mechanically or by an appropriate electronic system (process computerization).

Furthermore, the adjustment of the flow rate depends on the work to be carried out.

The arrangement of airbrushes can be achieved in different ways.

Thus, the airbrushes can be aligned (dis linear position), a determined number of airbrushes being juxtaposed at variable or fixed distances on the same axis.

According to another embodiment, the airbrushes can be arranged independently or in a group, each having autonomy of movement on a given plane. The two forms can be multiplied and / or combined. The two aforementioned provisions make it possible to fulfill different functions. On the other hand, these two arrangements can also have in addition to their horizontal movements a vertical displacement.

• - statique,
• - unilatéral (longitudinal ou transversal),
• - composé (longitudinal et transversal) rapport dit "XY" permettant toutes les combinaisons et configurations possibles dans une surface de plan. Ces mouvements peuvent être soit mécanisés soit informatisés.

Horizontally, the movement breaks down in three ways, namely:

• - static,
• - unilateral (longitudinal or transverse),
• - compound (longitudinal and transverse) report called "XY" allowing all possible combinations and configurations in a plane surface. These movements can be either mechanized or computerized.

In such an embodiment, the stencil can take different forms which may correspond to different uses.

It can thus, for example, be in the form of a frame used in a manner similar to traditional printing methods (fixed, on rail, etc.). Advantageously, according to this embodiment, the stencil consists of a frame on which is stretched a fabric made up of large stitches (one or two millimeters at most) whose threads are as fine as possible, this fabric having the characteristic offer as little resistance to air as possible. The motif to be reproduced is produced using existing photogravure methods.

Optionally, the stencil can be in the form of loose sheets used in the case of a winding system.

The stencils can also be in the form of rotating cylinders, for example in the case of continuous printing.

Finally, they can also be in the form of more or less long bands, fixed or circular, said bands then being scrolled.

Finally, it can be envisaged to engrave several stencils on the same support; for example, on the same frame, there can be different stencils.

• - la figure 1 est une vue schématique d'un dispositif permettant la mise en oeuvre du procédé selon l'invention par projection directe du colorant à la surface de l'étoffe à embellir ;
• - la figure 2 illustre un dispositif permettant la mise en oeuvre du procédé selon l'invention en utilisant un pochoir pour reproduire un motif décoratif sur l'étoffe ;
• - les figures 3 et 4 sont respectivement des vues transversale et longitudinale d'un dispositif comportant plusieurs pochoirs pour la réalisation d'un motif décoratif sur l'étoffe ;
• - la figure 5 illustre une variante d'un dispositif selon l'invention comportant également plusieurs pochoirs ;
• - la figure 6 illustre une variante dans laquelle les pochoirs se présentent sous la forme d'un cylindre ;
• - la figure 7 illustre une autre forme de réalisation d'un dispositif selon l'invention ;
• - la figure 8 est une vue schématique d'un type de buse (aérographe) utilisable pour réaliser la vaporisation (ou atomisation) du colorant conformément au procédé selon l'invention;
• - la figure 9 est une vue schématique d'une rampe de distribution des colorants par vaporisation, rampe dans laquelle une pluralité d'aérographes sont disposés en ligne ;
• - la figure 10 illustre une rampe de distribution des colorants par vaporisation comportant une pluralité d'aérographes disposés en forme d'épis.

The invention and the advantages which it brings will however be better understood thanks to the exemplary embodiments given below by way of indication but not limitation and which are illustrated by the appended diagrams in which:

• - Figure 1 is a schematic view of a device for implementing the method according to the invention by direct spraying of the dye on the surface of the fabric to be embellished;
• - Figure 2 illustrates a device for implementing the method according to the invention using a stencil to reproduce a decorative pattern on the fabric;
• - Figures 3 and 4 are respectively transverse and longitudinal views of a device comprising several stencils for the production of a decorative pattern on the fabric;
• - Figure 5 illustrates a variant of a device according to the invention also comprising several stencils;
• - Figure 6 illustrates a variant in which the stencils are in the form of a cylinder;
• - Figure 7 illustrates another embodiment of a device according to the invention;
• - Figure 8 is a schematic view of a type of nozzle (airbrush) used to carry out the spraying (or atomization) of the dye according to the method according to the invention;
• - Figure 9 is a schematic view of a spray dye distribution ramp, ramp in which a plurality of airbrushes are arranged in line;
• - Figure 10 illustrates a spray dye distribution ramp comprising a plurality of airbrushes arranged in the form of ears.

If reference is made to the appended figures, the device allowing the implementation of the methods according to the invention essentially consists of a table (1) on the plate (2) of which the fabric (3) is disposed. decorate.

The movement of this fabric (3) comes from a food roller (4) and is wound, after decoration, on a winding roller (5) disposed on the other side of the table (1).

The passage of the fabric (3) on the table (1) can be done either step by step, or at constant speed, or at progressive speed.

According to the invention, the table top (2) of the table (1) comprises, at least in the zone corresponding to that where the colored pattern is to be produced, a part (6) permeable to air. Optionally, the entire surface of the table can be breathable in which case an additional cover (7) can be used to mask the areas outside the printed pattern. The table (1) is in the form of a sealed box subjected to the action of a suction system making it possible to create a depression on the surface of the plate (2). This suction system can be constituted by a turbine (not shown) whose capacity is proportional to the surface of the fabric to be colored and whose flow rate can be modified as a function of the texture or density of the fabric and the surface of the decoration to be made. , surface possibly delimited by an additional shutter (7).

Above the table, is arranged an assembly, designated by the general reference (8) which will be, in the following description, designated by the expression "dye dispensing head" and which consists essentially of a plurality of nozzles (9) and formed in the present case of airbrushes of known type, making it possible to project said dye in the vaporized (or atomized) state against the surface of the fabric (3).

In the embodiment illustrated in FIG. 1, the dye is sprayed directly against the surface of the fabric (3).

The dye dispensing head (8) comprises a plurality of fixed airbrushes (9), arranged in line (see FIG. 9) transversely to the fabric (3) which itself runs at constant speed. The suction table being in operation, it is possible, in this embodiment, to obtain, by the diffusion of the coloring spray, a base dye of perfect unison. This coloration can vary as a function of the speed of movement of the fabric, the intensity of the spray jet, the height at which the ramp (9) is positioned relative to the surface of the fabric, by feeding the airbrushes themselves. (9) by dye, these airbrushes being able to individually receive one or more dyes with simultaneous change.

FIG. 2 illustrates a variant of a device according to the invention, variant according to which one or more additional stencils (10) will be interposed between the dye dispensing head (8) and the surface of the fabric (3). In this embodiment, the dye distribution head also consists of a ramp of airbrushes (9), removable, arranged in line and covering the entire width of the fabric.

As before, the dye distribution head (8) is adjustable in height. Each airbrush (9) is individually supplied with dyes. Furthermore, in order to obtain drying of the stencil (10) during and after deposition of the dye, a drying blower (11 blowing hot or cold air is also provided on said dispensing head (8).

The implementation of such a device is as follows.

The airbrushes (9) being arranged in a removable manner (that is to say spacable at precise and modifiable intervals) on an appropriate support. required, this ramp being itself arranged transversely to the fabric (3) which travels at constant speed, it is possible to obtain continuous stripes, either by using one or more stencils (10) having scratches in the longitudinal direction or even, possibly, even removing the stencil (10), the airbrushes (9) then being arranged at given intervals and the spray jets can be more or less refined, either by varying their intensity, or by modifying the height of the dispensing head (8). These two systems can be used concomitantly, thus making it possible to obtain continuous stripes of great complexity, both in terms of design and coloring.

Figures 3 and 4 illustrate respectively in transverse and longitudinal view a variant according to the invention in which the dye dispensing head (8) comprises a plurality of airbrushes (9) arranged in spikes as shown in the figure 10.

• - l'avancée du tissu maintenu droit fil ;
• - son arrêt par repérage mécanique, optique, électronique (une prise de robotisation étant prévue),
• - la tension et l'aspiration de turbine le maintenant fixe dans sa position lors des différentes phases d'impression.

In this variant, the device also comprises a suction table (1) and an adjustable shutter (7). Advantageously, according to this embodiment, the device comprises a complex winding system allowing:

• - the advancement of the fabric kept straight;
• - its stopping by mechanical, optical, electronic tracking (a robotization socket being provided),
• - the turbine voltage and suction keep it fixed in its position during the different printing phases.

The stencil (10) can, as shown in Figures 3 and 4, be in the form of frame or, optionally, in the form of free sheet.

When the stencil is in the form of a frame, these will be adapted to a mechanism which systematically and alternately positions them at a predetermined location, this in order to reconstitute the same design broken down into several stencils requiring meticulous location. In the event that continuous sheets are used as stencils, these, adapted on a winding system, scroll above the fabric to position themselves in a predetermined location.

As shown in Figure 3, the dye dispensing head is made up of a plurality of airbrushes (10 in this case), arranged in spikes as shown in detail in Figure 10. Each airbrush is supplied individually with dyes as well as a cleaning product and has a drain allowing its rapid cleaning. The controls for opening and closing aerographs are controlled remotely, mechanically or electronically. A programming device, memory and multiple orders, given to these airbrushes, is provided, This spray element is inscribed in a structure moving horizontally above the stencil in a longitudinal, transverse movement, and its compounds (report movement (XY) This movement is carried out mechanically, a control, memorization and order programming unit is incorporated. A low / high adjustment can be made depending on the intensity of the vaporization that one wishes to obtain.

The implementation of the device illustrated in Figures 3 and 4 is as follows.

The fabric (3) scrolls intermittently on the plate (2) of the table (1). This fabric (3) being immobilized, the appropriate stencil is positioned. This being done, the suction produced by the turbine is controlled. The operator (or the automation control member) activates the opening control of the airbrush corresponding to the dye to be dispensed and, simultaneously, orders the movement (XY ratio) of the dye distribution ramp to position the spray and color exactly where desired. In the same movement, several airbrushes (9) can be simultaneously or alternately actuated. The function of such a possibility is to allow the use of several dyes for the same stencil and to offer the possibility of degrading the colors between them, or even of composing new colors. The dye is sprayed against the surface of the screen. The suction system not only keeps the fabric (3) perfectly pressed, but, and this is what is its first function, forces the dye to pass through the voids in the stencil, to penetrate the fiber at its heart, while evacuating the surplus. During these operations, although the deposition of dye in accordance with the invention in the form of a vaporized (or atomized) mist, it can however be envisaged, in particular depending on the hygrometric degree of the workshop where the treatment is carried out, add to the installation a turbine pulsating air, hot or cold, directed at the very place where the dye is deposited on the stencil and this, to promote instant drying of the latter. As soon as the printing of a stencil is done, the spraying of dye is stopped and the positioning of the second stencil is accomplished after stopping or reducing the suction action. It should be noted that, in accordance with the invention, there is no drying time.

The staining process is carried out again according to the same process and so on until the stencils to be treated have been used up. Only then will the printed fabric move to repeat the process listed above.

FIG. 5 illustrates another embodiment of a device according to the invention.

Compared to the above examples, this device is characterized by the fact that it comprises a conveyor belt (12) consisting, for example, of a fabric like a sieve cloth, with large mesh allowing the passage of air. This conveyor belt (12) is driven by a mechanism allowing it to advance or stop in a precise and systematic manner. The fabric (3) is conveyed by said conveyor belt (12) and is kept pressed against the latter by the suction produced inside the table (1).

Above the fabric (3) and in its winding direction, are positioned one after the other different stencils (10a, 10b, 10c) necessary for all printing. Optionally, these stencils can be engraved on the same frame.

Above each frame (10a, 10b, 10c), there is a drying system (11a, 11b, 11c) as well as a line of airbrushes (9a, 9b, 9c) covering the width of the frame and driven in a horizontal, longitudinal or transverse movement. Each airbrush is supplied individually with dyes. The dye dispensing head (8) thus produced can also receive a vertical adjustment.

The implementation of the device illustrated in this FIG. 5 is as follows.

With the suction table running, the fabric (3) is secured to the conveyor belt (12) which carries it in a defined, precise and programmable movement. The stencils (10a, 10b, 10c) constitute the whole of the drawing to be printed and are positioned according to a specific locating to reconstitute, once the various phases of printing carried out, the initial drawing. The fabric (3) taken, between the stencils (10a, 10b, 10c) and the conveyor belt (12), advances intermittently at regular intervals and comes, by this movement, to position successively under the different stencils. Consequently, the stencil (10b) will be superimposed on the printing of the stencil (10a), then the stencil (10c) will in turn be superimposed on the printing of the stencils (10a) and (10b).

The printing of these three stencils, although independent, can be simultaneous. This impression is effected by a sweeping movement of the ramps of airbrushes which vaporize the dye. Each ramp covering a stencil, the movement of these ramps in a horizontal plane, can be longitudinal or transverse.

The airbrushes (9) being supplied individually with dyes, each having several dye arrivals, each scan may be composed of one color or as many colors as desired. Each airbrush can, in the same movement, distribute as many colors as its supply allows, the process of course being subject to computerization of the data.

FIG. 6 illustrates a variant of a device according to the invention, a variant which can be compared to the example described above and illustrated by FIG. 5, except that the stencils (10a, 10b, 10c) are are in the form of a cylinder or more or less long and circular bands. In this embodiment, the dye dispensing heads (8) are arranged inside the cylinders formed by the stencils (10a, 10b, 10c). The dispensing heads (8) also include, as before, means for drying the stencils.

The implementation of this device is as follows.

As in the example illustrated in Figure 5, the fabric su (3) is conveyed by the conveyor belt (12) and is kept pressed against the latter by the suction table (1). The stencils (10a, 10b, 10c) of cylindrical shape are pressed against the fabric by the same suction phenomenon and are therefore driven in the same movement.

It is possible, thanks to this installation, to obtain a so-called continuous printing.

FIG. 7 illustrates another form of implementation of the method according to the invention, comparable to that which is the subject of FIGS. 3 and 4, but which are essentially differentiated by the way in which the dye dispensing head (8) is produced. ). In this embodiment, the movement XY of the airbrush ramp (9) is replaced by a multitude of airbrushes and groups of fixed airbrushes covering, by their vaporization, the entire surface capable of being printed. Each airbrush is individually supplied with dyes and has an individual starting device. It is therefore possible, by actuating a defined choice of airbrushes, to have complex, precise and immediate coloring, and this on a single stencil.

Of course, the invention is not limited to the embodiments described above but it covers all the variants produced in the same spirit.

Thus, if the airbrushes used can be supplied with dye individually, it could be envisaged, as illustrated in FIG. 8, to supply the airbrush (9) by means of several dyes. In such a case, the airbrush (9) proper comprises an air inlet (20) as well as a system (21) for adjusting the spray rate. This airbrush is associated with a robotization member (22) for actuating the opening or closing. The supply of dye is, in this exemplary embodiment, carried out via a conduit (23) opening into the base of the airbrush (9) and which can be supplied either by means of a determined dye ( 24) either by means of a second dye (25) or by means of a cleaning product (26). Valves (28,29,30) are provided depending on the product to be introduced inside the airbrush. Furthermore, a purge (30) is also provided, this purge duct (30) also comprising a valve (31). It is therefore possible, thus using a single airbrush, to have it deliver different dyes.

Furthermore, any other device making it possible to cause vaporization or atomization of the dye could be used.

Finally, if in the examples given above, the table supporting the material has a flat surface, it could be envisaged to give it a convex shape.

Claims (3)

1. Process for decorating, by colouring, an article formed from fabrics (3) or from similar air-permeable products, which consists:

- in placing the article to be decorated flat on a table (1) having an air-permeable zone, this zone being subjected to the action of a suction system;

- in spraying the colouring substance against the surface of the article by means of a nozzle or nozzles (9) enabling the colouring agent, in the liquid state, to be sprayed in the form of a vaporized or atomized mist of colouring agent, the suction produced on the fabric being such that it enables the colouring agent to penetrate fully into the fabric and the excess to be removed, as well as it to be conveyed, in its journey through the open air, between the outlet of the nozzle (9) and the fabric (3), characterized in that:

- one or more screens or stencils (10) are placed in between the article and the colouring-agent source;

- the vaporized or atomized mist of colouring agent is produced such that an extremely fine or even molecular fragmentation of the said colouring agent is obtained, thus preventing the latter from wetting the fabric (3), the particles being sufficiently small to be dried instantly upon their contact with the fabric (3);

- the suction produced beneath the fabric (3) is such that it enables:

- the fabric (3) to be held against the table (1) during the various stages of its printing and the stencil (10) to be held flat against the surface of the said fabric (3);

- the colouring agent to dry instantly upon its contact with the fabric (3).

2. Process according to Claim 1, characterized in that, during the deposition of colouring agent, the fabric (3) is either held stationary or conversely is displaced at a constant or inconstant speed.

3. Process according to one of Claims 1 and 2, characterized in that an additional drying system (11 a, 11 b) such as a turbine propelling hot or cold air directed at the very point where the colouring agent is deposited on the stencil (10), is provided in order to promote the drying of the latter.

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