US3443878A - Method of continuously dyeing textile webs and the like - Google Patents

Description

y 1969 F. WEBER ETAL 3,443,878

METHOD OF CONTINUOUSLY DYEING TEXTILE WEBS AND THE LIKE Filed Feb. 8, 1965 Sheet of 5 76.! L, Y /0 .L /H 4: /4 2- l 3 m FR/EOR/CH WEBL'R AIELIIUT FUCHS KARL-JOACHIM KUNMER INVENTORS Aiiorney May 13, 1969 F. WEBER ETAL 3,443,378

METHOD OF CONTINUQUSLY DYEING TEXTILE WEBS AND THE LIKE Filed Feb. 8, 1965 Sheet 2 of 5 FIG. 3

mam/cu w'easn mnur rams mm-Jmcu/u A'UHHER INVENTOR Attorn Y May 13, 1969 F. WEBER ETAL METHOD OF CONTINUOUSLY DYEING TEXTILE WEBS AND THE LIKE Filed Feb. 8, 1965 FIG. 7

Sheet of5 F p AIR FRIEDRICH WEBER HELNUT FUCHS MRL 'JOACHIM KUMMER INVENTORS A! tomey May 13, 1969 F. WEBER ETAL METHOD OF CONTINUOUSLY DYEING TEXTILE WEBS AND THE LIKE Sheet J 015 Filed Feb. 8, 1965 FIG. 8

FRIEDRICH WEBER HELHUT FUCHS KARL 'JOACHIH KUHMER INVENTORS 3,443,878 METHOD OF CONTINUOUSLY DYEING TEXTILE WEBS AND THE LIKE Friedrich Weber, Zittau, Helmut Fuchs and Karl- Joachirn Kummer, Gross-Schonau, Germany, assignors to VEB Halbmond-Teppiche, Oelsnitz, Vogtland, Germany Filed Feb. 8, 1965, Ser. No. 431,129 Int. Cl. D06p /00 US Cl. 8-14 6 Claims ABSTRACT OF THE DISCLOSURE Method of and apparatus for the pattern dyeing of a substantially continuous fabric web in which a continuous stream of a liquid dyestuif is circulated along a closed path proximal to the web at a treating station and, at selected locations transversely of the web, portions of the dyestutf are deflected against the web under the control of a pattern programmer while the balance of the dyestuif continues uninterrupted along the closed path. Programmed pneumatic jets may be used to control the deflection of the circulated portions of the dyestuff stream.

Our present invention relates to the continuous production of patterned sheet material and, more particularly, to the patterned dyeing of continuous webs of textile fabrics, synthetic-fiber sheets and the like.

The continuous dyeing of fabrics and other sheet material in the form of continuous webs has been carried out heretofore in such manner as to produce a uniform coloring of the web or various color patterns. In the production of constant-color fabric bands and other continuous sheets, the web is either passed into a bath of the coloring material or sprayed continuously with the dyestutf from one or more nozzles as the web is displaced along a predetermined transport path. Color patterns can be produced continuously, according to earlier proposals in this field, by regulating (i.e. turning on and off the dye stream emanating from one or more of these nozzles in a programmed manner. Thus some areas of the fabric web pass the dyeing station without being sprayed whereas other areas are subjected to treatment with the fine particles of the dyestuif. The flow through the spray nozzles is conventionally regulated by the usual programming devices including electrical, mechanical or pneumatic mechanisms designed to control the valve and other elements regulating the rate of flow through the nozzle apertures.

While at first glance the intricacies of coloration and sharp delineation between colored and uncolored areas might be though to be a function only of the number of nozzles, the sizes of their apertures and the flow-rate of the dyestuff, more careful consideration will show that the conventional system described above are suitable only for the relatively coarse coloration and patterning of flexible and dye-retentive webs. This coarseness is due at least in part to the fact that the cut-off of flow through the nozzles by closing the valves supplying same is capable of only a limi ed sharpness in defining the amount of spray contacting the web. Valves for this purpose are, moreover, provided with relatively massive valve members whose movement necessitates the overcoming of considerable inertia and, therefore, the use of relatively large, powerful and somewhat sluggish control devices (e.g. solenoids, pneumatic pistons, and mechanical lever arrangements). In summary, therefore, it must be observed that the difliculties involved in the use of conventional systems for the pattern dyeing of textile fabrics and other continuous webs, wherein a plurality of nozzles are sup- 3,443,878 Patented May 13, 1969 "ice plied through on-off valves from a reservoir for the dyestuff, are primarily a consequence of the inability of valves of this type and their control systems to respond rapidly to changes in the desired pattern as determined by the programming unit; these problems are multiplied when the dyeing must be carried out upon rapidly movin g webs in order to be economical. Thus, the conventional systems, in order to produce a precise delineation or demarcation between dyed and undyed regions and, therefore, fine definition of color, require that the speed of the fabric band be relatively slow.

It is, consequently, the principal object of the present invention to provide an improved method of and apparatus for the pattern dyeing of textile fabrics and other continuous webs at relatively high speed but with good definition between the colored and uncolored regions.

A more specific object of this invention is to provide an apparatus of the character described enabling highspeed and low-inertia control of the elements regulating the dye jets.

A further object of this invention is to provide a method of pattern dyeing textile fabrics and other webs which permits fine patterns to be repeatedly and reproducibly generated, and which results in a saving in dyestuff while precluding blotching and running of the dye on the web.

These objects and others which will become apparent hereinafter are attained, in accordance with the present invention, by a method for the pattern dyeing of a continuously moving dye-retentive web along a transport or processing path, which includes the steps of circulating a dyestufi along a closed path at least a portion of which lies proximal to the web, and selectively diverting a portion of the dyestuff and projecting this portion in finely divided form out of the transport path against the web while the remainder of the dyestuff continues on its circulation path.

According to a more specific feature of this invention, the method involves the use of either of two different principles for effecting transfer of the dyestuff from its closed circulating flow to the fabric. In the first of these techniques, the dyestuff is directed generally transversely to the fabric web during the course of circulation and by the circulating means, but is selectively interceptable by deflecting means capable of redirecting the project stream along the circulating path. In the second technique, the dyestuif is conveyed along a path which can extend generally parallel to the web or, in more precise terms, along the web for a portion of its travel or generally in the direction of travel, while the deflecting means selectively diverts a portion of the dyestuff out of its circulating path and projects it in finely divided form against the web. In both cases, however, it will be understood that the dyestutf is continuously circulated while only a portion thereof is projected against the web and is retained thereby. An important advantage of the present invention is that the continuous circulation of the dyestuff imparts to the sprayed material a velocity enabling it to come into contact with the fabric while the control means is only required to selectively deflect either the return stream out of the projected stream or the projected stream out of the return flow to effect pattern dyeing. In the usual manner the control means can be provided with programming means coupled with the web-displacement means for establishing the pattern to be applied to the web.

A more specific feature of this invention resides in the provision of pneumatic means for deflecting the continuously circulating dyestuff in the manner discussed above. The pneumatic means can include a multiplicity of pneumatic jets directed at respective spray streams of the dyestutf projecting transversely and in the direction of the web so as to deflect the projected streams along a return path. Alternatively, the pneumatic jets can be directed against the web and can serve to project finely divided particles of the dyestutf from a freely-falling curtain thereof out of the circulating path and into contact with the dyestuif. In either case, a desired patterned effect is produced by the intermittent training of these jets upon laterally juxtaposed portions of a substantially cohesive curtain of liquid dyestuff, occupying a section of its closed-circulation path, in a zone proximal tothe web but separated therefrom by an air space, the pressure or absence of these jets causing the liquid dyestutf of the corresponding film portions to be selectively deviated from that path onto the moving web.

In another suitable arrangement, according to this improvement, the deflecting means comprises an intercepting element selectively positionable in front of an outlet through which the dyestutf is discharged for alternatively diverting it along a transport path and permitting it to stream into contact with the web. Even when pneumatic jets are provided as the deflecting means, fixed interceptors positioned adjacent an outlet opening toward the web preferably cooperate therewith to divert the deflected stream of dyestuff along its transport path. The pneumatic jets themselves may be controlled by valve members for the selective blocking and unblocking of the apertures of the jets or, according to a highly desirable arrangement, by the selective diversion of a. high-velocity stream of air into and out of alignment with such aperture. In all cases, however, the valve means do not directly block or unblock the passage from which the flow of dyestuif emanates. The intercepting means can, moreover, be part of a movable shield (e.g. formed as a continuous belt) whereby the sprayed particles can pass through the gaps in the shield formed by the interceptor means. The shield can, consequently, form the template according to which the pattern is produced.

The force field may also be formed by one or more pneumatic jets directed transversely to the dyestuff stream projected toward the web. The term pneumatic is used herein to distinguish the deflecting fluid, which can be any convenient gas, from the liquidcirculated through the treating station in the proximity of the web. Thus pneumatic fluids suitable for use with the present invention can include ambient air, bottled gases or air fractions as desired. The force field referred to above preferably cooperates with intercepting means in the form of a stationary shield disposed adjacent an outlet opening in the direction of the web and designed to intercept the dyestuff spray when the latter is diverted from this outlet.

In general, a multiplicity of parallel force fields will be applied transversely to the projected liquid in at least one row extending perpendicular to the direction of displacement of the web. Thus, a row of pneumatic jets may be provided, this row extending athwart the web and having individually controlled airflow rates programmed in accordance with the desired pattern. The force field's can be applied continuously so as to divert the dyestufl along its closed circulating path with deviation therefrom against the web being accomplished by deenergizing or terminating the force fields.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a diagrammatic elevational view illustrating the principles of the present invention according to one of the primary techniques described above;

FIG. 2 is a view similar to FIG. 1, diagrammatically showing the other of these primary techniques;

FIG. 3 is a fragmentary cross-sectional view through a treating station operating in accordance with the principles of FIG. 2;

FIG. 4 is a cross-sectional view taken along the line 1V-lV of FIG. 3;

FIG. 5 is a vertical cross-sectional view illustrating diagrammatically how a continuous shield-like template can be used in a system operating in accordance with the principles of FIG. 1;

FIG. 6 is a vertical cross-sectional view illustrating the use of multiple variable pneumatic force fields in a system of the general type shown in FIG. 1;

FIG. 7 is a fragmentary cross-sectional view illustrating another practical system for carrying out the method diagrammatically shown in FIG. 2; and

FIG. 8 is a cross-sectional view taken along the line VIIIVIII, of FIG. '7.

Throughout the specific description similarly functioning elements of the fabric-treating system will be described with the use of similar reference numerals distinguished by suflix letters (1, g, h, k) when the elements are structurally distinct. Identical elements, in terms of both function and structure, will have identical reference numerals throughout the description.

In FIG. 1, we show a fabric web 1 which is displaced in the direction of arrow X by suitable transport means diagrammatically represented by a pair of rollers 50, 51. The web 1 can be drawn from a suitable supply roll and, after passing the dyeing or treating station, can enter a drying stage and/or suitable washing, rinsing and dyesetting stages for subsequent fabric treatment before being wound again upon a takeup roll. The drive means 50, 51 are synchronized with the programming means 52 which may be of any conventional type and which controls the deflecting means represented generally at 4. The programming means may, for example, include a perforated band bearing the desired color pattern and through which the feelers of respective switch means can pass to electrically energize respective control elements of the deflecting means 4. The details of the co-operation between the programming mechanism and the elements controlled thereby will become more clear subsequently when specific pattern-dyeing systems are described. It should be noted, however, that the programming means coupled with the web-displacing means may also be constituted by photo-electrically scanned pattern-establishing tapes, cams, timing devices and similar programming controls (e.g. of the Jacquard type).

According to the principles of one aspect of the present invention, a liquid dyestuff or other treating material is displaced from a reservoir 5 by a circulating pump 6 in a closed path represented by the arrow Y and the reference numeral 53, at least a portion of the path lying in proximity to the web 1. In this system, this portion of the closed circulating path of the liquid dyestuff is formed by a freely cascading curtain 3 of the dyestuif discharged from one or more apertures 2 and collected by an interceptor 10 on the side of the curtain 3 opposite the outlet 2. In the instant embodiment, the interceptor 10 is constituted as a trough communicating with the reservoir 5. As previously described, this aspect of the present invention requires that the closed circulating path of the liquid dyestufi include a portion or segment wherein the dyestutf is displaced generally parallel to the web 1 while a deflecting means is selectively operable to divert a portion of the dyestuff out of this path and to project it against the web. Thus the deflecting means 4 provided at the side of the liquid curtain 3 remote from the web 1 is adapted to apply a deflecting-force gradient generally transversely to the curtain of liquid and to project at least some of this liquid against the web from the curtain 3 and pattern dye the web 1. The force field or gradient is indicated by the arrow 4 which can represent a row of pneumatic jets individually controlled to intercept the dyestuif curtain at spaced locations athwart the web and carry the dyestufi into contact with the web. Alternatively or additionally, the force field can be constituted by electrostatic or electromagneic means as will be apparent hereinafter. When pneumatic jets are employed, the air flow at the respective gap can be controlled by blocking and unblocking valves at the jet nozzles or apertures, by selectively aligning and disaligning high-velocity air streams with the respective apertures, and by other techniques as will become apparent hereinafter. The principles of the invention as illustrated in FIG. 1 will thus be readily apparent. As the liquid dyestuff is continuously circulated by the pump 6 to and from the curtain 3, a portion of the dyestuif can be selectively diverted by the deflecting means 4 and projected into contact with selected areas of the web 1 as determined by the programming means 52. If the de flecting means is rendered inoperative, the curtain 3 is not deflected and no coloration is imparted to the web.

In the system of FIG. 2, however, the fabric web 1, transported by the rollers 50, 51 as previously described, does not run parallel to a curtain of the liquid dyestuif traveling along its circulating path. At the treating station of the system of FIG. 2, the pump 6a circulates the liquid dyestuff from a reservoir 5a along the path Ya to the nozzle-like discharge apertures 2a which usually direct jets 3a of the liquid dyestufl against the web 1 in a direction perpendicular thereto. In this case, the deflecting means 4a acts transversely to the stream of liquid dyestutf 3a emanating from the outlet 2a in the direction of arrow 4a to divert it into an interceptor a when coloration of the web 1 is not required. The deflecting means 4a is again operated by a programmer 52a in step with the displacement of the web 1. Moreover, the deflecting means 4a acts to insure that the liquid dyestuff will be diverted upon its circulating path unless the deflecting means is so operated as to permit an undeflected stream to impinge upon the web. Again the deflecting means 4a may represent any advantageous system for applying a force field or deflecting-force gradient in the direction of arrow 4a (e.g. individually controlled pneumatic jets, electromagnetic fields or electrostatic fields), or mechanical shield means displaceable generally in the direction of arrow 4a to deflect the projected flow of dyestuff normal to the web 1. A suitable shield means may be formed by one or more fingers disposed above or below the stream 3a of dyestuff directed at the web 1 and individually or jointly displaceable by suitable control means to divert all or part of the dyestutf toward the fixedly positioned interceptor means 10a. Alternatively or additionally, the interceptor means 10a can be wholly or partly movable to constitute the shield by being displaced into the path 3a of the liquid projected normal to the gap 1. These alternatives will also be described in greater detail with reference to specific embodiments. It should also be noted that the reservoir 5, 5a and the pump 6, 6a of each embodiment, while shown to be remote from the nozzles or outlet apertures 2, 2a, need not be so in practice since the pump may :be disposed at or away from the outlet 2 or 2a.

More particularly, the dyeing station of FIG. 3 comprises a housing 55 formed with a pressure chamber 7] into which the dyestuff is forced by means of a pump 6] from a reservoir 5 communicating with the return compartment 12 of the housing. A plurality of nozzles 8 receive liquid dyestuff under pressure from the chamber 7 f and discharge it through apertures 21 lying in a row (FIG. 4) athwart the web 1 but transversely of its direction of travel X The aperture 2 and their respective nozzles 8 are trained upon an outlet slot 14] in a wall 55 of the housing, the slot 14 being flanked by a pair of lips 15]. Each of the nozzles 7 is provided with a respective port 29 in a housing portion 55f overlying the row of apertures 21, the ports 29 being coplanar with their respective nozzles so as to discharge a pneumatic jet transversely to the stream 3 of the dyestulf directed at the web 1 through the slot 14 The pneumatic jet of air or some other gas establishes a deflecting-force gradient across the stream 3f of dyestuff to produce a force field suflicient to bend the stream into intercepting relationship with a fixed shield 10 which diverts the stream (arrow 3f) to the compartment 12 and thence into the reservoir 5f. Each of the peumatic jets emerging from a respective outlet 29 is controlled by a valve member 32 individual to the jet nozzle and operated by a programming means to provide the desired dye pattern. The individually movable valve members or bodies 32 are mounted upon a common diaphragm or membrane 31 which is biased outwardly by the pneumatic pressure within a compartment 30 defined in the housing 55f. Air is supplied to the chamber 30 by a compressor or blower 30. It will thus be apparent that the pressure of the air serves to urge the several valve member 32 upwardly (arrow M) against the force of respective control tongues 33 anchored remote from the needle valves 32 at a common support 56 Whereas the programming means of the earlier-described device was required to lift the corresponding mechanical elements to effect deflection of the dyestuff streams, in the present case the tongues 33 are designed to restrain the needle valves 32 from movement in the direction of arrow M. For this purpose, staggered rows of solenoids 59 or other control means can be provided for controlling the individual members 33. The armatures 58 can then be coupled to the arms or tongues 33. The programming means can include a motor 52 those cams 52f each operate a respective solenoid 59f via a respective switch 527" functioning as a cam follower. When the switches 52f are closed by the cams 52 the corresponding solenoid 59 is operated to hold the valve 32 closed. Opening of the switches 521" by the timing motor 52 will deenergize the solenoid 59 and cause the respective tongues 33 to permit the valve 32 to open and thereby deflect the dyestulf stream. The programming means is merely representative of one which can be used with any of the herein described systems except that of FIG. 5. It should be noted, however, that it is also satisfactory to connect the tongues 33 to the respective valve members and reverse the action of the solenoids 59] so that they are capable of lifting the tongues or, alternatively, to provide the tongues 33 with an inherent resilience or stiffness suflicient to resist upward displacement of the needle valves 32 unless these tongues are lifted. A similar cam-operated control system may nevertheless be employed with, for example, normally closed switches which are opened by the cams. The solenoids of this embodiment can, moreover, be operated by any of the programming tapes described earlier. It is desirable, however, to couple the Web-transport means 50 with the motor 52 by, for example, a conventional servo-mechanism.

The device of FIG. 5 operates in accordance with the principle described with reference to FIG. 1 whereby the liquid dyestulf flows in a freely falling curtain from a supply source 7g through the outlet or outlets 2g generally parallel to the downwardly displaced web 1g (i.e. in the direction Xg). The curtain or film 3g of liquid dyestuif extends between the outlet apertures 2g and a collector or interceptor 10g forming a trough, in line with and below the apertures 2g, and communicating via a collecting compartment 12g with a reservoir 5g which feeds the pump 6g. The latter returns excess dyestuff to the chamber 7g via a float-valve assembly 62g.

An array of parallel and transversely spaced vertical wires or rods 34- extends from the outlet apertures 2g to the interceptor means 10g to stabilize the liquid curtain 3g. The latter passes in front of a deflecting means generally indicated at 4g and comprising an elongated air chamber 30g supplied with a pneumatic fluid by a pump 30g. The elongated and narrow outlet 29g of the deflecting means 4g is designed to dispense a sheet of highvelocity air capable of deflecting the liquid curtain toward the gap 1g as indicated by the arrow 3g". The region at which such deflection occurs is determined by a flexible endless template band 24g which passes over the deflecting rollers 25g and a shiftable, length-compensating roller 28g. The band 24g includes perforate and imperforate portions which reflect the flow of air normally trained upon the curtain 3g or prevent it from energinig from the outlet 29g in front of which the band passes. Perforated portions of the band thus correspond to regions of the web 1g at which dyestuff is transferred whereas nonperforated portions of the template correspond to areas in which the curtain 3g is undeflected and no color is transferred. The band-transport means 27g can be coupled with the web-transport means 51g as indicated in dot-dash lines.

The system of FIG. 6 is generally similar in operation to that of FIG. 5 and functions under the principle described previously in connection with FIG. 1. The deflecting means is, however, of the type illustrated in FIGS. 3 and 4. In the system of FIG. 6, the web 112 is displaced by the usual transport means 5111 in the direction of Xh generally parallel to a curtain 3h of liquid dyestuif stabilized by the transversely spaced parallel vertical wires 34 bridging the outlet 212 of the supply chamber 711 and the collecting and intercepting trough /1. The gathering compartment 12k, in which excess dyestuif is collected, supplies the reservoir 5k and the pump 6h which feeds the dyestuff to chamber 7h via the float valve 62h. The deflecting means 4h is here formed with a row of ports 29h extending parallel to the web 1h but perpendicularly to the direction Xh of displacement thereof. Each of the ports 29h (cf. FIG. 3) can be selectively opened and closed by a respective needle-valve body 32/: controlled by the spring fingers or tongues 33h fixed at their opposite extremities to the common support 561:. The valve bodies 3211 are mounted upon a diaphragm 31h forming a compartment 3011 to which air is supplied under pressure from a compressor 30k or some similar gas-supply means. The tongues 33h normally hold the valve bodies 3211 against displacement in the direction Mh by control means represented by the solenoids 59h whose armatures 5812 are adapted to entrain the respective tongues 3311 in the actuating direction Mh. As each of the solenoids 5911 along the row of ports 2911 is energized by the usual programming means, the jet of air trained upon the web 1h intercepts the curtain 312 of liquid dyestuff to deflect the latter onto the web. The programming means can be of any of the previously described types and is here represented as a punch card 5211 which is repeatedly passed between the brushes 52h and their countercontacts 52h (only one of which is shown) in circuit with each solenoid 59h. Punch-card programming of this type can also be used with all of the devices previously described and those to be described subsequently with the exception of the embodiments requiring templates to determine the pattern. The punch-card drive 59h is coupled with the web transport 5111. In the systems of FIGS. 11 and 12, the volume rate of flow of the curtains 3g and 311 can be adjusted by suitable valve means at the discharge apertures 2g and 2h, respectively, to permit adjustment of the angle at which the deflected liquid impinges upon the Web 1g or 1h. Similar adjustment can be effected by varying the speed of the pneumatic jets emanating from the outlets 29g and 29h. The rate of coverage of the web by the dyestuff and thus its penetration into the web can be modified by these latter adjustments and, additionally, by varying the speed of the web in the direction Xg or Xh.

An example of the control means for modifying the volume rate of flow of the curtain is illustrated in FIG. 6 from which it can be seen that a flap 211' at the outlet 21: is swingable to open and close this aperture, manual adjustment by means not illustrated being effective to swing this flap. When it is desired to produce colored strips on the fabric or otherwise impart coloration to only selected longitudinal bands of the web, a plurality of such flaps or valves can be provided; one or more of these valves can, therefore, be closed when no coloration is required in the corresponding regions of the web. Similar results can, of course, be obtained by appropriate setting of the programming means.

The arrangement illustrated in FIGS. 7 and 8 discloses a particularly advantageous system according to the present invention. In this case, the deflecting-force gradient is provided by pneumatic jets not unlike those of the system of FIGS. 3 and 4, although the jets here are not controlled by individual needle valves and relatively powerful relays, Solenoids or the like but by relatively small electrical energies. Thus, the web 1k is displaced in the direction of arrow Xk by the transport means k and passes in front of a plate k of the housing 55k whose pressure chamber 7k supplies the dyestuif to the individual nozzles 8k (FIG. 8). The nozzles 8k are trained upon an elongated slot 14k flanked by the forwardly converging lips 15k which define the undeflected-spray path 3k. Defiected spray, as indicated by arrow 3k, is intercepted by the fixedly positioned shield 10k and diverted into the collecting chamber 12k whence it is recirculated by the usual pump and reservoir arrangement to the chamber 7k. The deflecting means 4k of this embodiment includes an array of vertical, parallel and transversely spaced resiliently defiectable air tubes 43 anchored at one end in a wall 56k defining a manifold chamber 30k to which air under pressure is supplied via a pump 30k. The tubes 43 pass through a slotted partition 44 whose longitudinal knife edges 44" on opposite sides of the slot traversed by the tubes 43 form fulcra for the latter. Each tube 43 can thus be biased in a counterclockwise sense by a respective adjusting screw 44 about the fulcrum defined by the knife edges until the bottom extremities of the tubes come to rest against the abutment '45. The tubes 43 bear lightly against the abutment 45 in their rest positions in which the ends of the tubes register with respective ports 29k in the base of the respective guide channel 46 which permits each tube 43 to be temporarily and resiliently deflected in the direction of arrow Z. The ports 29k are disposed in respective vertical planes of the tubes 43 and the nozzles 8k so that, in a registering position of each tube and the corresponding port 29k, the respective stream of the dyestutf will be diverted as indicated by arrow 3k along the return circulation path.

Each of the tubes 43 is provided with a magnetically attractable (iron) armature 47 which co-operates with a respective electromagnetic system 48 whose two coils are connected in series. In order to permit the ports 29k and the corresponding air tubes 43 to lie close to one another and produce fine color patterns, the armatures 47 and electromagnetis 48 of adjacent tubes can lie in vertically spaced horizontal planes. Any of the programming means indicated earlier (as diagrammatically represented at 52k) may be used to energize the respective electromagnetic system selectively and in step with the rollers 50k. Selective energization of each electromagnetic device 48 will attract the respective armature 47 in the direction of arrow Z and offset the tube 43 from registry with the corresponding port 29k. The continuing flow of air through the deflected tube 43 is thus no longer effective to divert the corresponding spray stream, which passes through the outlet 14k undeflected and impinges upon the web 1k. When the tube 43 returns to its rest position, it again registers with the respective port 29k so that its high-velocity jet of air from chamber 30k is capable of deflecting the corresponding dyestuff stream. An opening in the housing of the deflecting means 4k permits lowpressure escape of air even when all of the tubes 43 are deflected. Since the tubes 43 can be made extremely long, their deflection can be carried out with a minimum of force, thereby enabling low-energy electrical sources and circuits to be used. In this case, therefore, powerful and massive switch arrangements are not required since the pneumatic energy is employed as the deflecting means and also as an amplifier for the output of the programming system.

It is evident, therefore, that the deflection of the liquid dyestuff streams can be carried out with substantially less mechanical or electrical force than required for conventional nozzle-closure arrangements. It may be stated in general, therefore, that the switch elements and programming devices can be made many times smaller for the purpose of the present invention than has heretofore been possible. In addition, the system of the present invention has a greater degree of reliability by virtue of the circulation of the dyestuff which precludes blockage of the discharge opening and nozzles. Since the kinetic energy of the dyestuff is always relatively high as a result of such circulation, the deflection pulses can be quicker and shorter, thereby enabling a finer patterning of the web.

It will be evident that the apparatus of the present invention as described and illustrated is subject to modification within the skill and ability of workers in the art without departing from the spirit and scope of the invention as claimed. For example, substitution of compatible elements from one embodiment in another system is highly obvious, since the programming devices specifically described in connection with FIGS. 3 and 6 can be used interchangeably and with the systems shown in FIGS. 7 and 8. While it is preferred to use vertical, free-flowing curtains of liquid in the systems of FIGS. 1, and 6, for example, it Will be apparent that these curtains can also be projected generally parallel to the Web if required but at an angle to the vertical. Many other modifications will be evident to those skilled in the art.

We claim:

1. A method of pattern dyeing a continuous web of sheet material, comprising the steps of:

substantially continuously circulating a liquid dyestuff along a closed path;

forming a substantially cohesive curtain of said dyestuff along a section of said path in a zone proximal to said web but separated therefrom by an unobstructed air space;

continuously displacing said Web past said zone; and

intermittently training jets of a pneumatic fluid upon laterally juxtaposed portions of said curtain in said zone for selectively diverting the liquid dyestuff from said path onto said web to produce a patterned effect thereon.

2. A method as defined in claim 1 wherein the curtain passes parallel to said web in said zone.

3. A method as defined in claim 2 wherein the curtain is formed by letting the dyestufr" fall freely through said zone.

4. A method as defined in claim 2 wherein said web is moved in the same direction as the curtain of liquid dyestuff.

5. A method as defined in claim 1 wherein a template is interposed in the path of said jets at said zone.

6. A method as defined in claim 1 wherein said curtain is directed toward said web in said zone and is deflected therefrom by said jets.

References Cited UNITED STATES PATENTS 1,403,126 1/1922 Lyth 8151 2,221,776 11/1940 Carlson 961.4 2,676,100 7/1956 Huebner 118-627 2,876,737 3/1959 Carlson 118637 FOREIGN PATENTS 229,351 7/ 1926 Great Britain. 236,194 9/ 1926 Great Britain.

DONALD LEVY, Primary Examiner.

US. Cl. X.R.

Images