Method and apparatus for thermal patterning of textile subtrates

Description

[0001] This invention relates to a method and apparatus for pressurized heated fluid stream treatment of relatively moving substrate materials. In a particular embodiment, this invention relates to a method and apparatus for selectively applying streams of heated air to a thermally modifiable substrate to impart a visual change in the substrate surface, especially a pattern effect having a relatively high apparent resolution.

[0002] Methods and devices of the prior art disclose techniques for imparting a pattern on fabric by means of directing one or more streams of heated air onto relatively moving, thermally modifiable substrates such as textile fabrics comprising thermoplastic fibers. Some contributors have relied upon stencils and masks placed between a source of heated air and the substrate surface to generate the requisite pattern-wise impingement of air streams on the substrate. Generally speaking, a major problem with stencil and mask systems, such as that disclosed in Belgian Patent BE-A-766,310, to Kratz, et al., has been the limitation imposed upon the process by the necessity of having a mechanical stencil or mask, interposed between the heated air source and substrate, which must map exactly every detail of the pattern, regardless of how delicate or complex or extensive the pattern may be. Having to generate, maintain, and position accurately a stencil having a highly intricate pattern is extremely difficult in a commercial, production environment. An additional problem with such systems, moreover, is a general inability to generate patterns in which untreated areas are completely surrounded by treated areas, e.g., a closed, treated boundary both surrounding and surrounded by untreated areas.

[0003] Other contributors to this art have relied upon various nozzles or pre-formed jets to form and direct the streams of heated air which strike the substrate surface.

[0004] Systems using pre-formed jets, such as those disclosed in US―A―3 613 186 (Mazzone et al.), US―A―3256581 (Thal et al.), and US-A-3 774 272 (Rubaschek et al.), are generally limited to patterning a substrate with an array of grooves a.. mged in relatively simple patterns - usually merely continuous grooves extending generally along the direction of substrate movement.

[0005] GB-A-2 065 035 discloses a system wherein pressurized heated fluid, for example, air, may be distributed along a slot which extends the length of an elongate reservoir or manifold. The air is formed into a thin, elongate stream within the manifold, before the air exits as a curtain from a continuous slot extending along the length of the manifold. Streams of blocking fluid, e.g., relatively cool air, are then used to block selectively the flow of selected segments of the elongate stream by selectively directing, from within the manifold, such streams of blocking fluid across the gap formed by the elongate manifold slot at selected locations along the length of the manifold, thereby diverting portions of the thin blade of heated air generated by the elongate manifold before the curtain of air exits from the manifold slot.

[0006] By using an array of aligned, transverse bfock- ing streams or jets of relatively cool air to generate, within the manifold, a plurality of selectively positioned heated air streams from a single elongate heated air stream without the use of a shim plate, extreme versatility, speed, and reproducibility are achieved, and patterns incorporating untreated areas having closed, treated boundary lines, as well as extended line segments which are substantially perpendicular to the direction of substrate travel, are possible. However, it has been found that where extreme detail and pattern resolution are desired, the transverse blocking air jet system discussed above is not totally satisfactory. Efforts to develop a system in which the transverse air streams within the manifold slot are aligned and spaced along the length of the manifold as closely as, for example, 20 per linear inch (25.4 mm), allowing for the selective blocking of the curtain of heated air at any of 20 pre-determined locations along any one inch (25.4 mm) working segment of the manifold slot, have not been entirely satisfactory. When such density is attempted, it is believed fluid mechanical effects within the slot, perhaps as a result of mutual interference between adjacent blocking jets, cause the blocking effect to spread or diffuse, so that the blocking effect extends over a larger segment of the slot length than is desired, and the appearance of the resulting pattern is degraded. This disadvantageous effect is particularly dramatic where, for example, among a group of three adjacent blocking jets, the pattern requires the first and third blocking jets to block portions of the heated air stream, and requires the second blocking jet to remain off, thereby permitting a single thin stream of heated air, having a width approximately equal to the region which would be blocked by the second jet acting alone, to squarely strike the substrate. Under this circumstance, the blocking effect of the activated first and third jets tends to encroach into the heated air stream segment controlled by the second jet, causing a kind of pinching effect which tends to attenuate or block the heated air stream segment in the region of the second jet when no such attenuation or blocking is desired.

[0007] It has now been discovered that, if blocking jets are to be arranged in a relatively high density, aligned configuration, for example, at least about six to eight jets per linear centimetre, the disadvantages discussed above can be substantially eliminated if segments of the pressurized heated air stream are not blocked within the elongate manifold, but rather diverted and diluted after, preferably immediately after, an intact elongate heated air curtain exits the slot in the elongate manifold. The method of this invention is accordingly characterised in that the heated fluid is projected from the said slot directly and uniformly in a continuous curtain extending along the length of the reservoir, and that at least one precisely defined segment of the continuous curtain is diverted in a direction away from the substrate surface after the fluid has left the slot.

[0008] The apparatus of this invention is characterised in that the fluid diverting means are located outside the discharge slot of the manifold where they act upon a continuous curtain of heated fluid projected from the slot to divert at least one segment of the fluid curtain after it has left the slot.

[0009] In a preferred embodiment of the invention, an array of air jets is positioned immediately outside of the slot in the manifold so as to dilute and divert from the substrate surface precisely defined segments of selectable length from the substantially continuous elongate stream or curtain of pressurized heated air which exits from the manifold slot, while not disturbing the paths of other precisely defined segments of the elongate heated air stream or curtain which are directed at precisely pre-determined areas on the relatively moving substrate surface.

[0010] Details of this invention, together with the accompanying drawings, are discussed in the following detailed description, in which:

Figure 1 is a schematic side elevation view of apparatus for pressurized heated fluid stream treatment of a moving substrate material to impart a surface pattern or change in the surface appearance thereof, and incorporating novel features of the present invention;

Figure 2 is an enlarged partial sectional elevation view of the fluid distributing manifold assembly of the apparatus of Figure 1, taken along a section line of the manifold assembly indicated by the line 11-11 in Figure 7;

Figure 3 is an enlarged sectional view of the elongate manifold assembly, taken generally along line III-III of Figure 2 and looking in the direction of the arrows;

Figure 4 is an enlarged side elevation view of end portions of the elongate baffle member of the manifold assembly, looking in the direction of arrows IV-IV of Figure 2;

Figure 5 is an enlarged broken away sectional view of the fluid stream distributing manifold housing portion of the manifold assembly as illustrated in Figure 2;

Figure 6 is an enlarged, schematicized plan view of end portions of the fluid stream distributing manifold housing looking in the direction of the arrows VI-VI of Figure 2; and

Figure 7 is an enlarged plan view of end portions of the manifold assembly, taken generaiiy along fine Vii-Vii of Figure 2 and looking in the direction of the arrows;

Figure 8 is an enlarged plan view of end portions of the manifold assembly, taken generally along line VIII-VIII of Figure 5 and looking in the direction of the arrows;

Figure 9 is a diagram of shrinkage vs. temperature (experimentally determined) for several thermally modifiable substrate constituent fibers.

[0011] Referring more specifically to the drawings, Figure 1 shows, diagrammatically, an overall side elevation view of apparatus for pressurized heated fluid stream treatment of a moving substrate material to impart a high resolution pattern or visual change thereto. As seen, the apparatus includes a main support frame including end frame support members, one of which, 10, is illustrated in Figure 1. Suitable rotatably mounted on the end support members of the frame are a plurality of substrate guide rolls which direct an indefinite length substrate material, such as a textile fabric 12, from a fabric supply roll 14, past a pressurized heated fluid treating unit, generally indicated at 16. After treatment, the fabric may be collected in a continuous manner on a take-up roll 18. As shown, fabric 12 from a supply roll 14 passes over an idler roll 20 and is fed by a pair of driven rolls 22, 24 to a main drive fabric support roll 26, whereby the surface of the fabric is passed closely adjacent the heated fluid discharge outlet of an elongate fluid distributing manifold assembly 30 of treating unit 16. The treated fabric 12 thereafter passes over a series of driven guide rolls 32, 34 and an idler roll 36 to take up roll 18 for collection. For purposes of discussion, the following discussion will assume air is the preferred fluid. It should be understood, however, that other fluids may be used.

[0012] As illustrated in Figure 1, fluid treating unit 16 includes a source of compressed fluid, such as an air compressor 38, which supplies pressurized air to an elongate air header pipe 40. Header pipe 40 communicates by a series of air lines 42 spaced uniformly along its length with a bank of individual electrical heaters indicated generally at 44. The heaters 44 are arranged in parallel along the length of manifold assembly 30 and supply heated pressurized air thereto through short, individual air supply lines, indicated at 46, which communicate with assembly 30 uniformly along its full length. Air supply to the fluid distributing manifold assembly is controlled by a master control valve 48, pressure regulator valve 49, and individual precision control valves, such as needle valves 50, located in each heater air supply line 42. The heaters are controlled in suitable manner, as by temperature sensing means located in the outlet lines 46 of each heater, with regulation of air flow and electrical power to each of the heaters to maintain the heated air at a uniform temperature and pressure as it passes into the manifold assembly along its full length. Typically, for patterning textile fabrics such as pile fabrics containing thermoplastic pile yarns, the heaters are employed to heat air exiting the heaters and entering the manifold assembly to a uniform temperature of about 700°F-800°F (371-427°C) or more.

[0013] The heated fluid distributing manifold assembly 30 is disposed across the full width of the path of movement of the fabric and closely adjacent the surface thereof to be treated. Typical surface spacing is 0.010 to 0.020 inch (0.25-0.5 mm). Although the length of the manifold assembly may vary, typically in the treatment of textile fabric materials the length of the manifold assembly may be 76 inches (1.93 m) or more to accommodate fabrics of up to about 72 inches (1.83 m) in width.

[0014] As illustrated in Figure 1 and in Figure 7, the elongate manifold assembly 30 and the bank of heaters 44 are supported at their ends on the end frame support members 10 of the main support frame by support arms 52 which are pivotally attached to end members 10 to permit movement of the assembly 30 and heaters 44 away from the surface of the fabric 12 and fabric supporting roller 26 during periods when the movement of the fabric through the treating apparatus may be stopped.

[0015] Details of the heated fluid distributing manifold assembly may be best described by reference to Figures 2-7 of the drawings. As seen in Figure 2, which is a partial sectional elevation view through the assembly, taken along line II-II of Figure 7, the manifold assembly 30 comprises a first large elongate manifold housing 54 and a second smaller elongate manifold housing 56 secured in fluid tight relationship therewith by a plurality of spaced clamping means. The manifold housings 54, 56 extend across the full width of the fabric 12 adjacent its path of movement. A plurality of manually-operated clamps 60 are spaced along the length of the housings. Each clamp includes a portion 62 fixedly attached, as by spaced bolts 58 and brackets 124, to side wall 74 of the first manifold housing 54, as well as an adjustable threaded screw assembly 68 with elongate presser bars 70 which apply pressure to manifold housing 56. Screws 59 may be used to secure presser bars 70 to the top surface of upper wall member 140 of housing 56.

[0016] As best seen in Figure 2, first elongate manifold housing 54 is of generally rectangular cross- sectional shape, and includes a pair of spaced plates forming side walls 74, 76 which extend across the full width of the path of fabric movement, and elongate top and bottom wall plates 78, 80 which define a first elongate fluid receiving compartment 81, the ends of which are sealed by end wall plates 82 suitably bolted thereto. Communicating with bottom wall plate 80 through fluid inlet openings 83 (Fig. 4) spaced uniformly therealong are the heated air supply lines 46 from each of the electrical heaters 44. The side walls 74, 76 of the housing are connected to top wall plate 78 in suitable manner, as by welding, and the bottom wall plate 80 is removably attached to side walls 74, 76 by bolts 84 to permit access to the first fluid receiving compartment 81. The plates and walls of the housing 54 may be formed of suitable high strength material, such as stainless steel or the like.

[0017] The manifold housings 54, 56 are constructed and arranged so that the flow path of fluid through the first housing 54 is generally at a right angle to the discharge axes of the fluid stream outlets of the second manifold housing 56. In addition, the mass comprising side walls 74, 76 and top and bottom wall plates 78, 80 of first manifold housing 54 is substantially symmetrically arranged on opposing sides of a plane bisecting the first fluid receiving compartment 81 in a direction parallel to the elongate length of manifold housing 54 and parallel to the predominant direction of fluid flow, i.e., from inlet openings 83 to passageways 86, through the housing compartment 81. Because the mass of the first housing 54 is arranged in a generally symmetrical fashion with respect to the path of the heated fluid through the housing compartment 81, thermal gradients and the resulting thermally-induced distortions in the first housing 54 also tend to be similarly symmetrical. As a consequence, any distortion of the manifold assembly caused by expansion and contraction due to temperature differentials tends to be resolved in a plane generally parallel to the surface of the textile fabric 12 being contacted by the heated fluid streams. This resolution of movement of the manifold assembly minimizes any displacement of the manifold discharge outlet channels 115 (Fig. 5) toward or away from the fabric 12 as a result of non-uniform thermal expansion of the manifold assembly. Any remaining unresolved thermally-induced displacement of the manifold housing 54 may be corrected by use of jacking members or other means to supply corrective forces directly to the manifold housing.

[0018] As best seen in Figures 2, 3, and 7, upper wall plate 78 of manifold housing 54 is of relatively thick construction and is provided with a plurality of fluid flow passageways 88 which are disposed in uniformly spaced relation along the plate in two rows to communicate the first fluid receiving compartment 81 with a central elongate channel 88 in the outer face of plate 78 which extends between the passageways along the length of plate 78. As seen in Figures 3 and 7, the passageways in one row are located in staggered, spaced relation to the passageways in the other row to provide for uniform distribution of pressurized air into the central channel 88 while minimizing strength loss of the elongate plate 78 in the overall manifold assembly.

[0019] As seen in Figures 2 and 4, located in first fluid receiving compartment 81 and attached to the bottom wall plate 80 of the housing 54 by threaded bolts 90 is an elongate channel-shaped baffle plate 92 which extends along the length of the compartment 81 in overlying relation to wall plate 80 and the spaced, fluid inlet openings 83. Baffle plate 92 serves to define a fluid receiving chamber in the compartment 81 having side openings or slots 94 adjacent wall plate 80 to direct the incoming heated air from the bank of heaters in a generally reversing path of flow through compartment 81. As seen in Figure 2, disposed above channel-shaped baffle plate 92 in compartment 81 between the fluid inlet openings 83 and fluid outlet passageways 86 is an elongate filter member 96 which consists of a perforated, generally J-shaped plate 98 with filter screen 100 disposed thereabout. Filter member 96 extends the length of the first fluid receiving compartment 81 and serves to filter foreign particles from the heated pressurized air during its passage therethrough. Access to the compartment 81 by way of removable bottom wall plate 80 permits periodic cleaning and/or replacement of the filter member, and the filter member 96 is maintained in position in the compartment 81 by frictional-engagement with the side walls 74, 76 to permit its quick removal from and replacement in the compartment 81.

[0020] As best shown in Figures 2 and 5, second smaller manifold housing 56 comprises first and second opposed elongate wall members 140 and 170. When disposed as shown, in spaced, coextensive, parallel relation, members 140 and 170 form a second fluid receiving compartment, shown generally in Figure 5 at 160, which serves to divert the air at a right angle, and further serves to form the air into a long, relatively thin curtain or blade which extends the full width of wall members 140, 170, and which is uniform with respect to temperature, pressure, and velocity.

[0021] In order to selectively interrupt continuously selectable, precisely defined lateral segments of this thin, continuous curtain or blade of pressurized heated air and prevent the pressurized heated air from striking the surface of closely spaced substrate 12 within such segments, and at the same time present substantially no interruption or modification to the heated air in all remaining, complementary segments along the length of this curtain or blade of air, a uniform array of tubes 126 is positioned immediately outside the forward-most portion of wall member 140. Tubes 126 are positioned to divert the path of a precisely defined segment of the continuous curtain of air in a direction such that the diverted segment will not impinge directly upon the substrate surface to any significant degree, but will instead be directed in a plane approximately perpendicular to the plane defined by the path of those segments of the curtain or blade which are undiverted and which are intended to squarely strike the substrate surface. Dilution of these diverted segments also takes place, which lowers the temperature of these segments as well. In this way, the lateral configuration of the blade of air striking the substrate can be controlled, and pattern information may be imparted to the substrate surface, i.e., the curtain of air originating within compartment 160 may be reduced to one or more discrete, narrow streams of air which strike the substrate squarely, while those diverted segments of the curtain strike the substrate either obliquely or not at all, and are in either case relatively cooler than the undiverted segments, due to the diluting effects of the diverting air streams, and therefore have relatively little or no permanent effect on the substrate.

[0022] Figures 5 and 6 disclose the details of second fluid receiving compartment 160, the ends of which are closed by end plates 111 (Fig. 7). Compartment 160 may be thought of as two chambers 162, 166 in serial arrangement, each compartment extending the length of manifold housing 56, and each chamber being followed by a throttling orifice comprising a relatively thin slot 168, 115 of individually uniform but not necessarily equal gap width extending the length of compartment 160. Heated air which has been mixed in first manifold compartment 81 enters second fluid receiving compartment 160 at a pressure of from about 0.1 to about 5 p.s.i.g. or more by way of a plurality of individual fluid inlets 118 which communicate with elongate channel 88 of the first manifold housing 54 along its length. Gallery 163 within chamber 162 serves to mix the air from individual inlets 118, whereupon the air flows into the remaining portion of chamber 162. In this remaining portion of chamber 162, the air is made to flow the width of the chamber, thereby mixing with air already present in the chamber. Support partitions 164 act as load bearing and separating members between wall members 140 and 170. As can be seen in Figure 6, partitions 164 have rounded and portions, straight sides, and are tapered (included angle approximately 14°) to a point having a radius of approximately 0.01 inch. This is done primarily to avoid causing turbulence in the fluid flow path within this portion of chamber 162. It is foreseen that other turbulence-minimizing configurations for support partitions 164 are possible.

[0023] At the forward end of chamber 162, ridge or weir 165 is used to define slot 168, which acts as a throttling orifice between chamber 162 and adjoining chamber 166. By passing through slot 168, which forms a uniform gap extending the length of wall members 140, 170, a reduction in fluid pressure is effected which allows chamber 166 to act as an expansion chamber. By expanding, the fluid in chamber 166 tends to become uniform with respect to temperature, velocity, and pressure. Chamber 166 can be thought of as the immediate reservoir from which air is formed into a blade-like exit stream via discharge slot 115. Wall segments 141, 142 and 171, 172 merely serve to define a transition area between chamber 166 and discharge slot 115 which does not generate substantial entrance effects. Rough edges within chamber 166 or within this transition area should be avoided. It is foreseeable that other configurations for chamber 166, such as forming the walls of chamber 166 in an appropriate curve, would further minimize entrance effects, but such curves are generally expensive to machine, and have been found to be unnecessary in this embodiment in most applications. It is suggested, however, that regardless of the chamber cross- sectional shape, the maximum ratio of chamber height (dimension "A" in Figure 5) to the height or gap of slot 168 should be on the order of 10 or more, and preferably 14 or 16 or more. It is estimated that the overall effect of slot 168, expansion chamber 166, and discharge slot 115 is to introduce a dynamic head loss on the other of 4.0 with respect to air in chamber 162. It has been found that dynamic head losses of at least 3.0 are most suited to generating the uniform flow desired. Dynamic head losses of about 4.0 or more are recommended for most purposes, as this amount of dynamic head loss is usually sufficient to assure a practically uniform fluid stream emerging from discharge outlet 115. Discharge slot 115 is formed from opposing flat surfaces on the forward portion of wall members 140, 170, and is also of some uniform gap height all along the length of members 140,170. Where a discharge slot gap height (i.e., measured parallel to dimension "A") of about 0.018 inch (0.46 mm) is used, a discharge slot depth (i.e., measured in the direction of fluid flow) of about 0.38 inch (9.6 mm) has been found advantageous.

[0024] It should be noted that, due to the design of elongate wall members 140 and 170, machining of said wall members may be relatively simple. The load bearing surfaces of wall members 140, 170 may be smoothly machined in a single operation to ensure a fluid tight seal for chambers 162, 166. The lower surface of wall member 140, forming the upper wall portion of discharge slot 115, the upper wall portion of slot 168, and the upper load bearing surfaces above chamber 162 and to the rear of gallery 163, may be made coplanar. Similarly, those portions of wall portion 170 defining the lower load bearing surfaces to the rear of gallery 163, the load bearing surfaces atop support partitions 164, the upper surface of ridge 165 defining slot 168, and the lower wall portion of discharge slot 115 may all be co-olanar. The lower surface of wall member 140 may be machined by cutting channels corresponding to the upper portion of gallery 163 and wall segments 141, 142 comprising the upper portions of chamber 166, and similar appropriate machining may be used to form the lower portions of gallery 163, chamber 162, and the lower wall members 171, 172 comprising the lower portions of chamber 166.

[0025] In addition to simplifying greatly the fabrication of wall members 140 and 170, this design also allows the gap width of discharge slot 115, as well as the gap width of slot 168, to be set merely by inserting flat, rectangular spacer shims 112, 116 of equal thickness between the mating wall members 140, 170, as shown in Figure 5. This allows for simple, quick adjustment of the gap size of discharge slot 115 in response to requirements imposed by changes in substrate material or visua! =ffect desired. It is foreseen that shim thicknesses ranging from 0.005 inch (0.13 mm) or less to 0.035 inch (0.9 mm) or more may be used. It is believed the exact dimensional relationship which this design imposes is not important to the operation of the manifold compartment 160. Thus, for example, it is foreseen that throttling - - slot 168 need not have the same gap size as discharge slot 115. The depth of discharge slot 115 may require adjustment at extreme gap sizes in order to prevent turbulence within the slot 115.

[0026] Lower wall member 170 of the second manifold housing 56 is provided with a plurality of fluid inlet openings 118 which communicate with the elongate channel 88 of the first manifold housing 54 along its length to receive pressurized heated air from the first manifold housing 54 into the second fluid receiving compartment 160. Wall members 140, 170 of the second manifold housing 56 are maintained in fluid tight relation with spacing shim members 112, 116 and with the elongate channel 88 of the first manifold housing 54 by clamps 60, as well as by bolts 122 which may extend through wall members 140 and into wall member 170, or may extend through wall members 140, 170 and into wall plate 78. Because of the cantilevered design of housing 56, it is advantageous to align presser bar 70 with the forward portion of support partitions 164.

[0027] As shown in Figures 2 and 5, the forward portion of wall member 170 carries vents 174 which allow a small quantity of heated air to be bled from chamber 162, thereby assuring a small but steady flow of air through chamber 162. Such flow not only prevents the build-up of stagnant, heated air within chamber 162, thereby causing uneven temperature distribution within compartment 160, but also assists in preventing excessive heat build-up in the vicinity of the heater elements 44 and premature heater burn-out. An additional advantage is that the passage of the heated bleed air through vents 174 in lower wall member 170 serves to maintain temperature in the forward section wall member 170 which is subject to cooling via impingement of relatively cool air or other fluid from cool air tubes 126 discussed in more detail below, attached to the forward portion of upper wall member 140. Bleed air baffle 182, which extends across the full width of lower wall member 170 and which is attached to side wall 76 at regular intervals by means of screws 188 and spacers 186, prevents air from tubes 126 or slots 115 from being entrained by bleed air from vents 174. Baffle wier 184 creates slight backpressure downstream of vent 174, within cavity 180, which prevents air from tubes 126 or slot 115 from being entrained via small unintended and undesirable gaps between baffle 182 and lower wall member 170. Baffle 182 need extend only sufficiently far from wall member 170 to prevent significant interaction between bleed air from vents 174 and air from tubes 126 or slot 115.

[0028] As seen in Figures 1, 2, 5 and 7 of the drawings, discharge slot 115 of the second manifold housing 56 is provided with a plurality of tubes 126, preferably uniformly spaced along the forward edge of wall member 140, which communicate at roughly a right angle to the axis of discharge slot 115. These tubes 126 direct individual streams of pressurized, relatively cool fluid, for example, air having a pressure of at least about 1 to 10 times the pressure of the air exiting slot 115 and a temperature substantially below that of the heated air in chamber 166, transversely past discharge slot 115 to selectively divert and diffuse or dilute the flow of heated air over selected segments at selected points along the length of slot 115 in accordance with pattern control information. As seen in Figure 1, pressurized unheated air is supplied to each of the tubes 126 from compressor 38 by way of a master control valve 128, pressure requlator valve 129, air line 130, and unheated air header pipe 132 which is connected by a plurality of individual air supply lines 134 to the individual tubes 126. Each of the individual cool air supply lines 134 is provided with an individual control valve located in a valve box 136. These individual control valves are operated to open or close in response to signals from a pattern control device, such as a computer 138, to deflect and dilute selected intervals or segments of the curtain of hot air at selected locations outside and along the length of slot 115 during movement of the fabric and thereby produce a desired pattern in the fabric. Adjacent tube spacing along the length of slot 115 is sufficiently close to avoid any leakage of heated air from between two adjacent positions of tubes 126 when such tubes are fully activated, thereby allowing the width of the individual segment or segments which are diverted or diluted to be a pattern variable. It is foreseeable that, for certain pattern effects, controlled "leakage" of heated gas through or between the cool air streams produced by individual or adjacently positioned tubes 126 may be desirable. This can be achieved by, for example, reducing or modulating the pressure of the air in selected ones of tubes 126 while said selected tubes 126 are supplying diverting air streams. Detailed patterning information for individual patterns may be stored and accessed by means of any known data storage medium suitable for use with electronic computers, such as paper or magnetic tape, EPROMs, etc.

[0029] As depicted in Figures 2, 5, and 7, tubes 126 are positioned immediately in front of discharge slot 115, with the mouth of each tube 126 being positioned in alignment along a line parallel to slot 115 and slightly above the forward edge of upper wall member 140 which forms the mouth of discharge slot 115. Cooling means such as a cold water manifold is not required to prevent excessive heating of the air in tubes 126, for several reasons. Tubes 126, being mounted externally to upper wall member 140, are not subject to as much heating from upper wall member 140 as might be experienced where tubes 126 are in more direct contact with member 140. Additionally, because the air from tubes 126 does not contact directly the substrate surface, but rather serves to divert and dilute the heated air from slot 115, rather than block such air, incidental heating of the air in tubes 126 can be more easily accommodated with little or no effect in the resulting patterning. To facilitate secure, proper positioning and alignment of tubes 126, eacti tube -- - may be secured to a block 143 by means of brazing, ceramic adhesive, or other means. Block 143 in turn may be detachably secured to upper wall member 140 by means of screws 144 or other means. The exact position of the mouths of tubes 126 in relation to the stream of air exiting slot 115 may be adjusted by means of, for example, shims inserted between mating surfaces of block 143 and wall member 140. Optimum positioning of the mouths of tubes 126 depends of course upon the dimensions of tubes 126 and slot 115, as well as the respective pressures of the exiting curtain of heated air and the relatively cool diverting air streams, among other things. It has been found, for a slot thickness of 0.015 to 0.025 inch (0.38-0.63 mm), a tube inside diameter of 0.033 inch (0.84 mm), a tube outside diameter of 0.0042 inch (0.107 mm), a tube spacing (from tube centerline to adjacent tube centerline) of 0.05 inch (1.3 mm), a heated air pressure of 0.5 p.s.i.g. (0.035 kg/cm²) and a cool air pressure of 3 p.s.i.g. (0.2 kg/cm²), positioning the mouths of tubes 126 approximately .025 to .100 inch (0.63 to 2.54 mm) above the upper edge of slot 115 (i.e., above the lower edge of wall member 140) is satisfactory, although other configurations and spacings may be advantageous under certain circumstances. It is generally recommended that the rearward portion of the interior walls of tubes 126 be mounted in the same plane as the forward edge of wall member 140, so that the forward edge of wall member 140 serves as an extension of a portion of the interior walls of tubes 126. In this particular case, therefore, the central axis of the tubes 126 may be positioned approximately 0.0175 inches (0.44 mm) (exactly one tube bore radius) from the forwardmost edge of wall member 140. It should be understood, however, that other positions for tubes 126 may be found to be satisfactory, and may be superior, for this or other combinations of air temperatures and pressures, slot thicknesses, etc. It is also foreseen that tubes 126 preferably may be flared rather than having a uniform bore, depending upon conditions.

[0030] In operation, heated air generated by heaters 44 flows through inlet openings 83, and is directed through compartment 81 to passageways 86 and elongate channel 88. Upon entering fluid receiving compartment 160, the heated air is directed through a series of chambers and gaps intended to assure the air exiting compartment 160 is totally uniform with respect to temperature, pressure, and velocity. Upon exiting compartment 160, including chambers 162 and 166, the air exits via slot 115 as a thin blade or curtain of heated air, directed onto a moving substrate positioned opposite and in close proximity to the mouth of slot 115. The exact spacing between the mouth of slot 115 and the substrate surface is dependent upon the visual effect desired on the substrate, the nature of the substrate, and other factors. The spacing is of course limited by the space occupied by the tubes 126 and any mounting means associated with the tubes. Generally speaking, the distance between the mouth of slot 115 and the top-most portion of substrate 12 will be between about 0.040 inch and about 0.25 inch (1.1 and 6.3 mm) under ordinary conditions, although spacings outside this range are possible. Selected intervals or lateral segments of this curtain of heated air may be diverted and diluted by relatively cool, high pressure air, directed substantially perpendicularly to the plane of the heated air curtain from tubes 126. The lateral segments which are not diverted are permitted to strike the substrate surface and induce a visual change in the surface thereby. The selected lateral segments diverted by the relatively cool air streams from tubes 126 either strike the substrate obliquely or not at all; in either case, the segments are diluted or diffused to such an extent that no substantial visual effect is produced. Where the resulting streams of heated air are maintained at a sufficiently high temperature and directed onto a substrate comprised of a thermally modifiable material, for example, thermoplastic materials such as polyester, polyamide, polyolefin, or acrylonitrile fibers or yarns, substantial longitudinal shrinkage of individual fibers or yarns, as well as localized melting or fusing of individual fibers or yarns, or other thermally induced changes in the physical character and visual appearance of the material, can be induced. Such shrinking or melting or fusing can in turn result in the permanent patterning of the substrate by, for example, causing sculpturing or puckering of the substrate, or by creating a visual contrast between treated and untreated areas, either with or without an additional, post-treatment dyeing step. Suggested temperatures on the substrate at which shrinkage of various substrate constituents occurs is given in Figure 8. The following examples describe further details of the invention disclosed herein.

Example I

[0031] A knit polyester plush pile fabric having a weight of thirteen ounces per square yard (433 g/ m²) and a pile height of one tenth of an inch (2.5 mm) was continuously fed through the apparatus illustrated in Figure 1 at a speed of fabric travel of three and one-half yards per minute. The temperature and pressure of the heated air in the manifold compartment 81 was maintained at 620°F (327°C) and 0.37 p.s.i.g., (0.026 kg/cm²) respectively. The height (gap) of slot 115 was 0.018 inch (0.46 mm) and the distance between the mouth of slot 115 and the fabric was set at 0.08 inch (2.1 mm). The deflecting air jet tubes 126 were set 0.050 inch (1.3 mm) above slot 115 and were spaced apart along the upper lip of the manifold 56 with the forward-most portion of member 170 aligned with the inside edge of the tube bore. The tubes were made from 0.027 inch (0.68 mm) inside diameter hypodermic tubes 4 inches long, bored out 0.033 inch (0.8 mm) xO.125 inch (3.18 mm) deep at the discharge end. The bore of the tube just contacted the upper lip of manifold 56. The deflecting air pressure through tubes 126, measured prior to the solenoid valves controlling deflecting air flow, was set at 3 p.s.i.g. (0.2 kg/cm²). The treated fabric possessed a pattern composed of longitudinally shrunken fibers where the hot air had been allowed to contact the fabric.

Example II

[0032] A polyester plain weave fabric having a fabric weight of three and one-half ounces per square yard (117 g/m²), and a 92 warp end by 84 pick end per inch (25.4 mm) fabric construction, was processed through the apparatus of Figure 1 at a fabric speed of four yards (3.64 m) per minute. The temperature and pressure of the heated air in the manifold compartment 81 was maintained at 690°F (366°C) and 0.8 p.s.i.g. (0.06 kg/cm²), respectively. The height (gap) of slot 115 was 0.018 inch (0.46 mm) and the distance between the mouth of slot 115 and the fabric was set at 0.08 inch (2.1 mm). The deflecting air jet tubes 126 were set 0.050 inch (1.3 mm) above slot 115 and were spaced along the upper lip of manifold 56 with the forwardmost portion of member 170 aligned with the inside edge of the tube bore. The tubes were made from 0.027 inch (0.68 mm) inside diameter hypodermic tubes 4 inches long, bored out 0.033 inch (0.8 mm) xO.125 inch (3.18 mm).deep at the discharge end. The bore of the tube just contacted the upper lip of manifold 56. The deflecting, air pressure through tubes 126, measured prior to the solenoid valves controlling deflecting airflow, was set at 4.5 p.s.i.g. (0.3 kg/cm²). The treated fabric possessed a pattern composed of longitudinally shrunken fibers where the hot air had been allowed to contact the fabric.

Claims

1. A method of treating a moving substrate to impart a visual pattern thereto, the method comprising:

(a) generating an elongate reservoir of uniformly heated pressurised fluid extending across the path of movement of the substrate;

(b) fixing the relative position of the substrate path in spaced but closely adjacent relation to the reservoir;

(c) forming within the reservoir a thin elongate fluid stream, the said stream extending substantially continuously along the length of the reservoir;

(d) projecting a curtain of fluid in the direction of the substrate surface from a continuous slot extending along the length of the reservoir;

(e) diverting a precisely defined lateral segment of the elongate heated fluid stream at least at one location along the length of the reservoir, thereby preventing areas of the substrate surface opposite the diverted lateral segment of the heated fluid stream from being impinged upon and thermally modified by the said segment while other lateral segments of the stream are projected in the fluid curtain onto areas of the substrate surface and impinge on the surface;

(f) maintaining the temperature of the heated fluid stream at a uniform level along the length of the reservoir, the said level being sufficient to enable the lateral segments of the fluid stream squarely impinging on the surface to modify thermally the surface appearance of the substrate: and

(g) moving the substrate on the said path and into the stream projecting from the reservoir;

characterised in that the heated fluid is projected from the said slot directly and uniformly in a continuous curtain extending along the length of the reservoir, and that at least one precisely defined segment of the continuous curtain is diverted in a direction away from the substrate surface after the fluid has left the slot.

2. A method according to claim 1 characterised in that the diverted lateral segment is diluted while being diverted.

3. A method according to claim 2 characterised in that the lateral segment is diverted by a relatively cool fluid stream directed across the projected heated continuous curtain.

4. A method according to claim 3 characterised in that the pressure of the diverting relatively cool fluid stream is varied in accordance with pattern information.

5. A method according to claim 3 or 4 characterised in that the lateral segment is diverted by a plurality of relatively cool fluid streams aligned along the length of the reservoir, at least two of the relatively cool fluid streams being adjacently spaced to divert and dulute substantially all of the said curtain within the region along that length of the reservoir defined by the adjacent cool fluid streams.

6. A method according to claim 3 or 4 characterised in that the axis of the cool fluid stream is oriented at approximately a 90° angle from the direction in which the heated curtain is projected.

7. A method according to any of claims 1 to 6 characterised in that the diverting of the lateral segment of the curtain is intermittent and for a predetermined duration, the duration being determined by pattern information continuously supplied at the same time as the substrate is moving across the path of the projected curtain.

8. A method according to claim 7 characterised in that selected segments of the heated gas curtain are selectively diverted to impart a surface pattern effect which varies irregularly along the length of fabric movement.

9. A method according to any of claims 1 to 8 characterised in that the substrate contains thermoplastic yarns, and that the temperature and pressure of the heated fluid segments squarely impinging on the substrate are maintained at a sufficient level to longitudinally shrink the thermoplastic yarns contacted thereby.

10. Apparatus for treating a relatively moving substrate by application of pressurised heated fluid to selected surface portions thereof to thermally modify and alter the visual surface appearance of the substrate, the apparatus comprising: a manifold (30); means (38-44) for supplying heated fluid under pressure to the manifold; a narrow, elongate, fluid discharge slot (115) extending along the length of the manifold for projecting a continuous curtain of fluid in the direction of the substrate surface, means (126) for selectively diverting at least one lateral segment of the heated fluid so as to prevent such fluid from impinging on the substrate surface; and means (26) for supporting the substrate (12) and effecting relative movement of the substrate past the slot at a location such that the substrate is impinged upon by that portion of the heated fluid which is undiverted by the diverting means: characterised in that the fluid diverting means are located outside the discharge slot of the manifold where they act upon a continuous curtain of heated fluid projected from the-slot to divert at least one segment of the fluid curtain after it has left the slot.

11. Apparatus according to claim 10 characterised in that the elongate manifold (30) is comprised of first (54) and second (56) elongate manifold housings secured in fluid tight relationship, the first manifold housing defining a fluid flow path into the second manifold housing which is substantially perpendicular to the path of fluid being projected from the second manifold housing in the direction of the substrate.

12. Apparatus according to claim 10 or 11, characterised in that the means for selectively diverting the lateral segment of fluid includes means (126) outside the said manifold (30) for selectively directing a stream of cooler pressurised fluid perpendicular to the slot (115) and across the path of the said curtain at at least one selected location along the length of the slot.

13. Apparatus according to claim 12, characterised in that the means for selectively directing the cooler fluid includes a plurality of individual orifices (126), aligned in parallel with the slot (115), each orifice being associated with individual valve means (136) to permit the initiation of interruption of a flow of pressurised coolerfluid in accordance with pattern information continuously supplied to the valve means.

14. Apparatus according to claim 13 characterised in that the individual valve means (136) is associated with a pattern information source (138) which supplies such pattern information to the individual valve means automatically.

15. Apparatus according to any of claims 12 to 14 characterised in that the means for selectively directing the cooler fluid comprises a plurality of individual tubes (126) having a bore axis which is substantially perpendicular to the discharge axis of the slot (115).

16. Apparatus according to claim 15 wherein the plurality of tubes (126) are uniformly positioned along the length of the slot (115) with sufficiently close spacing between adjacent tubes to prevent any portion of the heated fluid curtain from passing between the streams of diverting fluid associated with the adjacent tubes and squarely impinging on the substrate surface.

Ansprüche

1. Verfahren zum Behandeln eines bewegten Substrates, um diesem ein wahrnehmbares Muster zu erteilen, bei welchem:

a) ein langgestrecktes Reservoir von gleichförmig erwärmtem Druckfluid erzeugt wird, das sich quer über die Bewegungsbahn des Substrates erstreckt;

b) die Relativlage der Substratbahn mit Abstand vom Reservoir, aber diesem eng benachbart festgelegt wird;

c) innerhalb des Reservoirs ein dünner langgestreckter Fluidstrom erzeugt wird, der sich im wesentlichen kontinuierlich über die Länge des Reservoirs erstreckt;

d) ein Fluidvorhang aus einem kontinuierlichen, sich über die Länge des Reservoirs erstreckenden Schlitz auf die Substratoberfläche abgegeben wird;

e) ein genau definiertes Quersegment des langgestreckten erwärmten Fluidstromes zumindest an einer Stelle entlang der Länge des Reservoirs abgelenkt wird, wobei verhindert wird, daß dem abgelenkten Quersegment des erwärmten Fluidstromes gegenüberliegende Zonen der Substratoberfläche beaufschlagt und durch dieses Segment thermisch verändert werden, während andere Quersegmente des Stromes im Fluidvorhang auf Zonen der Substratoberfläche abgegeben werden und auf diese auftreffen;

f) die Temperatur des erwärmten Fluidstromes über die Länge des Reservoirs auf einem gleichmäßigen Niveau gehalten wird, wobei dieses Niveau ausreicht, damit die auf die Oberfläche gerade auftreffenden Quersegmente des Fluidstromes die Oberflächenerscheinung des Substrates thermisch verändern; und

g) das Substrat in der Bewegungsbahn weiter und in den vom Reservoir abgegebenen Strom bewegt wird;

dadurch gekennzeichnet, daß das erwärmte Fluid aus dem Schlitz direkt und gleichförmig in Form eines kontinuierlichen Vorhanges abgegeben wird, der sich über die Länge des Reservoirs erstreckt, und daß zumindest ein genau definiertes Segment des kontinuierlichen Vorhanges in einer Richtung von der Substratoberfläche weg abgelenkt wird, nachdem das Fluid den Schlitz verlassen hat.

2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das abgelenkte Quersegment verdünnt wird, während es abgelenkt wird.

3. Verfahren nach Anspruch 2, dadurch gekennzeichnet, daß das Quersegment von einem relativ kühleren Fluidstrom abgelenkt wird, der quer über den abgegebenen erwärmten kontinuierlichen Vorhang gerichtet ist.

4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß der Druck des ablenkenden relativ kühlen Fluidstroms entsprechend der Musterinformation geändert wird.

5. Verfahren nach Anspruch 3 oder 4, dadurch gekennzeichnet, daß das Quersegment von einer Vielzahl relativ kühler Fluidströme abgelenkt wird, die über die Länge des Reservoirs ausgerichtet sind, wobei zumindest zwei der relativ kühleren Fluidströme einander benachbart im Abstand angeordnet sind, um im wesentlichen den gesamten Vorhang innerhalb des durch die benachbarten kühlen Fluidströme gebildeten Bereiches entlang der Länge des Reservoirs abzulenken und zu verdünnen.

6. Verfahren nach Anspruch 3 oder 4, dadurch gekennzeichnet, daß die Achse des kühlen Fluidstromes unter einem Winkel von etwa 90° zu jener Richtung orientiert ist, in welcher der erwärmte Vorhang abgegeben wird.

7. Verfahren nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß das Ablenken des Quersegmentes des Vorhanges intermittierend und über eine vorbestimmte Zeitspanne erfolgt, die von der Musterinformation bestimmt wird, welche kontinuierlich zugleich mit der Bewegung des Substrates über die Bahn des abgegebenen Vorhanges zugeführt wird.

8. Verfahren nach Anspruch 7, dadurch gekennzeichnet, daß ausgewählte Segmente des erwärmten Gasvorhanges selektiv abgelenkt werden, um einen Oberflächeneffekt zu bewirken, der unregelmäßig über die Länge der Stoffbewegung variiert.

9. Verfahren nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, daß das Substrat thermoplastische Garne enthält und daß die Temperatur und der Druck der erwärmten Fluidsegmente, welche auf das Substrat gerade auftreffen, auf einem ausreichenden Niveau gehalten werden, damit die von diesen beaufschlagten thermoplastischen Garne in der Längsrichtung schrumpfen.

10. Vorrichtung zum Behandeln eines relativ bewegten Substrates durch Aufbringen eines erwärmten Druckfluids auf ausgewählte Oberflächenteile des Substrates, um die wahrnehmbare Oberflächenerscheinung des Substrates zu modifizieren und zu ändern, wobei die Vorrichtung umfaßt: einen Verteiler (30); eine Einrichtung (38-44) zum Zuführen von erwärmtem Druckfluid zum Verteiler; einen schmalen langgestreckten Fluidabgabeschlitz (115), der sich über die Länge des Verteilers erstreckt, um einen kontinuierlichen Fluidvorhang in Richtung auf die Substratoberfläche abzugeben; eine Einrichtung (126) zum selektiven Ablenken zumindest eines Quersegmentes des erwärmten Fluids, um zu verhindern, daß dieses Fluid auf die Substratoberfläche auftrifft; und eine Einrichtung (26) zum Abstützen des Substrates (12) und zur Relativbewegung des Substrates am Schlitz an einer Stelle vorbei, derart, daß das Substrat von jenem Teil des erwärmten Fluids getroffen wird, der von der Ablenkeinrichtung unabgelenkt bleibt: dadurch gekennzeichnet, daß die Fluidablenkeinrichtung außz-rhalb des Abgabeschlitzes des Verteilers angeordnet ist, wo sie auf einen vom Schlitz abgegebenen kontinuierlichen Vorhang erwärmten Druckfluids einwirkt, um zumindest ein Segment des Fluidvorhanges abzulenken, nachdem dieser den Schlitz verlassen hat.

--11-. Vorrichtung nach Anspruch 10, dadurch gekennzeichnet, daß der langgestreckte Verteiler (30) aus ersten (54) und zweiten (56) langgestreckten Verteilergehäusen besteht, die miteinander fluiddicht verbunden sind, wobei das erste Verteilergehäuse einen Fluidströmungsweg in das zweite Verteilergehäuse definiert, der im wesentlichen senkrecht zur Bahn des vom zweiten Verteilergehäuse in Richtung auf das Substrat abgegebenen Fluids ist.

12. Vorrichtung nach Anspruch 10 oder 11, dadurch gekennzeichnet, daß die Einrichtung zum selektiven Ablenken des Quersegmentes des Fluids eine Einrichtung (126) außerhalb des Verteilers (30) aufweist, um selektiv einen Strom kühleren Druckfluids senkrecht zum Schlitz (115) und quer über die Bahn des Vorhanges an zumindest einer ausgewählten Stelle über die Länge des Schlitzes auszubringen.

13. Vorrichtung nach Anspruch 12, dadurch gekennzeichnet, daß die Einrichtung zum selektiven Ausbringen des kühleren Fluids eine Vielzahl von einzelnen Austrittsöffnungen (126) aufweist, die parallel zum Schlitz (115) ausgerichtet sind, wobei jeder Austrittsöffnung einzelne Ventilmittel (136) zugeordnet sind, um die Unterbrechung eines Stromes kühleren Druckfluids entsprechend der den Ventilmitteln kontinuierlich zugeführten Musterinformation zu veranlassen.

14. Vorrichtung nach Anspruch 13, dadurch gekennzeichnet, daß den einzelnen Ventilmitteln (136) eine Musterinformationsquelle (138) zugeordnet ist, welche den einzelnen Ventilmitteln diese Musterinformation automatisch zuführt.

15. Vorrichtung nach einem der Ansprüche 12 bis 14, dadurch gekennzeichnet, daß die Einrichtung zum selektiven Ausbringen des kühleren Fluids eine Vielzahl von einzelnen Rohren (126) aufweist, deren Bohrungsachse im wesentlichen senkrecht zur Abgabeachse des Schlitzes (115) verläuft.

16. Vorrichtung nach Anspruch 15, bei welcher mehrere Rohre (126) über die Länge des Schlitzes (115) gleichmäßig positioniert sind, mit ausreichend engem Abstand zwischen benachbarten Rohren, um zu verhindern, daß irgendein Teil des erwärmten Fluidvorhanges zwischen den benachbarten Rohren zugeordneten Strömen des Ablenkfluids passiert und auf die Substratoberfläche gerade auftrifft.

Revendications

1. Procédé de traitement d'un substrat en déplacement pour y créer un dessin visuel, le procédé comportant:

(a) créer un réservoir, de forme allongée de fluide sous pression chauffé uniformément s'étendant de part et d'autre du trajet du substrat;

(b) fixer la position relative du trajet du substrat à une certaine distance, mais très près du réservoir;

(c) former à l'intérieur du réservoir un fin courant de fluide de forme allongée, ledit courant s'étendant sensiblement en continu sur la lon---gueur du réservoir;

(d) projeter un rideau du fluide dans la direction de la surface du substrat à partir d'une fente continue s'étendant sur la longueur du réservoir;

(e) dévier un segment latéral, défini avec précision, du courant de fluide chauffé de forme allongée, au moins en un emplacement sur la longueur du réservoir, empêchant ainsi les zones de la surface substrat situées en face du segment latéral, ainsi dévié, du courant de fluide chauffé d'être heurtées et thermiquement modifiées par ledit segment tandis que d'autres segments latéraux du courant sont projetés dans le rideau de fluide sur des zones de la surface du substrat et heurtent cette surface;

(f) maintenir la température du courant de fluide chauffé à un niveau uniforme sur la longueur du réservoir, ledit niveau étant suffisant pour permettre aux segments latéraux du courant de fluide de heurter perpendiculairement la surface pour modifier thermiquement l'aspect de la surface du substrat; et

(g) déplacer le substrat sur ledit trajet et dans le courant qui se projette depuis le réservoir;

caractérisé en ce que le fluide chauffé est projeté, à partir de ladite fente, directement uniformément, en un rideau continu s'étendant sur la longueur du réservoir; et en ce qu'au moins un segment, défini avec précision, du rideau continu est dévié dans une direction qui l'écarte de la surface du substrat après que le fluide a quitté la fente.

2. Procédé selon la revendication 1, caractérisé en ce que le segment latéral dévié est dilué tout en étant dévié.

3. Procédé selon la revendication 2, caractérisé en ce que le segment latéral est dévié par un jet de fluide relativement froid et dirigé en travers du rideau continu chaud projeté.

4. Procédé selon la revendication 3, caractérisé en ce que l'on fait varier la pression du jet de fluide relativement froid de déviation en fonction du l'information concernant le dessin.

5. Procédé selon la revendication 3 ou 4, caractérisé en ce que le segment latéral est dévié par une pluralité de jets de fluide relativement froid alignés sur la longueur du réservoir, au moins deux des jets de fluide relativement froid étant espacés l'un de l'autre de façon telle qu'ils dévient et diluent sensiblement la totalité dudit rideau à l'intérieur de la région, sur la longueur du réservoir, définie par les jets voisins de fluide froid.

6. Procédé selon la revendication 3 ou 4, caractérisé en ce que l'axe du jet de fluide froid est orienté sous un angle d'environ 90° par rapport à la direction dans laquelle le rideau chaud est projeté.

7. Procédé selon l'une quelconque des revendications 1 à 6, caractérisé en ce que la déviation du segment latéral du rideau est intermittente et pendant une durée prédéterminée, cette durée étant déterminée par une information concernant le dessin fournie en continu en même temps que le substrat se déplace en travers du trajet du rideau projeté.

8. Procédé selon la revendication 7, caractérisé en ce que l'on dévie sélectivement des segments sélectionnés du rideau de gaz chaud pour créer un effet de dessin de surface qui varie de façon irrégulière sur la longueur du déplacement du tissu.

9. Procédé selon l'une quelconque des revendications 1 à 8, caractérisé en ce que le substrat contient des filés thermoplastiques et en ce que l'on maintient la température et la pression des segments de fluide chaud qui heurtent perpendiculairement le substrat à un niveau suffisant pour rétracter longitudinalement les filés thermoplastiques qu'ils contactent.

10. Appareil pour traiter un substrat en déplacement relatif par application d'un fluide chaud sous pression pour sélectionner des portions de surface de ce substrat pour modifier thermiquement et changer l'aspect visuel de surface du substrat, l'appareil comportant: un distributeur (30); des moyens (38―44) pour envoyer sous pression au distributeur un fluide chauffé; une fente étroite et de forme allongée (115) d'émission du fluide s'étendant sur la longueur du distributeur pour projeter un rideau continu de fluide dans la direction de la surface du substrat; des moyens (126) pour dévier sélectivement au moins un segment latéral du fluide chaud de façon à empêcher ce fluide de heurter la surface du substrat; et des moyens (26) pour supporter le substrat (12) et assurer le déplacement relatif du substrat devant la fente en une position telle que le substrat est heurté par la portion du fluide chaud qui n'est pas déviée par les moyens de déviation, caractérisé en ce que les moyens de dévier le fluide sont situés à l'extérieur de la fente d'émission du distributeur où ils agissent sur un rideau continu de fluide chauffé projeté hors de la fente, pour dévier au moins un segment du rideau fluide après qu'il a quitté la fente.

11. Appareil selon la revendication 10, caractérisé en ce que le distributeur de forme allongée (30) est constitué d'un premier carter (54) et d'un second carter (56) de forme allongée du distributeur fixés, de façon étanche au fluide, le premier carter de distributeur définissant, dans le second carter du distributeur, un trajet d'écoulement du fluide sensiblement perpendiculaire au trajet du fluide projeté hors du second carter de distributeur, dans la direction du substrat.

12. Appareil selon la revendication 10 ou 11, caractérisé en ce que les moyens prévus pour dévier sélectivement le segment latéral de fluide incluent des moyens (126) situés à l'extérieur dudit distributeur (30) pour diriger sélectivement un jet de fluide sous pression plus froid perpendiculairement à la fente (115) et en travers du trajet dudit rideau en au moins un emplacement sélectionné sur la longueur de la fente.

13. Appareil selon la revendication 12, caractérisé en ce que les moyens prévus pour envoyer sélectivement le fluide plus froid incluent une pluralité d'orifices individuels (126), alignés en parallèle avec la fente (115), chaque orifice étant associé à un moyen (136) formant robinet individuel pour permettre de démarrer ou d'interrompre un flux de fluide plus froid sous pression conformément à une information concernant un dessin fournie en continu au moyen formant robinet.

14. Appareil selon la revendication 13, caractérisé en ce que le moyen (136) formant robinet individuel est associé à une source d'information (138) concernant le dessin qui envoie. automatiquement cette information concernant le dessin au moyen formant robinet individuel.

15. Appareil selon l'une quelconque des revendications 12 à 14, caractérisé en ce que le moyen prévu pour envoyer sélectivement le fluide plus froid comporte une pluralité de tubes individuels (126) dont l'axe de l'alésage est sensiblement perpendiculaire à l'axe d'émission de la fente (115).

16. Appareil selon la revendication 15, dans lequel la pluralité de tubes (126) sont placés uniformément sur la longueur de la fente (115), avec un espacement suffisamment faible entre les tubes voisins pour empêcher qu'une portion du rideau de fluide chaud ne puisse passer entre les jets du fluide de déviation associé aux tubes voisins et ne puissent tomber perpendiculairement sur la surface du substrat.

Drawing