US3263458A

US3263458A - Apparatus for dyeing tubular knit material

Info

Publication number: US3263458A
Application number: US302094A
Authority: US
Inventors: Cohn Samuel; Cohn Eugene; Catallo Frank
Original assignee: Samcoe Holding Corp
Current assignee: Samcoe Holding Corp
Priority date: 1960-09-13
Filing date: 1963-08-14
Publication date: 1966-08-02
Anticipated expiration: 1983-08-02

Description

Aug. 2, 1966 s. COHN ET AL 3,263,458

APPARATUS FOR DYEING TUBULAR KNIT MATERIAL Original Filed Sept. 13. 1960 5 Sheets-Sheet l INVENTORS SAMUEL COHN EUGENE COHN BY FRANK CATALLO ww/wmpzw gab ATTORNEY Aug. 2, 1966 s. COHN ET AL APPARATUS FOR DYEING TUBULAR KNIT MATERIAL 5 Sheets-Sheet 2 )riginal Filed Sept. 13 1960 o w N SHNU. .ZJQ m wm a TCCA JN N C R U wa am mum K T MGM A AU R SEF L W Y B w m u i NN ll United States Patent 3,263,458 APPARATUS FQR DYEING TUBULAR KNIT MATERIAL Samuel Cohn, New York, Eugene (john, Great Neck, and Frank Catallo, Elmont, N.Y., assignors to Samcoe Holding Corporation, Woodside, N.Y., a corporation of New York Continuation of application Ser. No. 55,672, Sept. 13, 1960. This application Aug. 14, 1963. Ser. No. 302,094 5 Claims. (Cl. 6822) This application is a continuation of our copending application Serial No. 55,672, filed September 13, 1960, now abandoned.

The present invention relates to the treatment of tubular knitted fabrics, and more particularly to novel and improved method and means for continuously dyeing tubular knit material in a manner to provide a dyed tubular fabric free of edge marks.

The dyeing of fabrics is desirably carried out on a continuous basis, by directing a web of bleached or scoured material through a bath of dye liquor and uniformly impregnating the material with the dye. Such continuous dyeing has been carried out successfully with woven materials, for example, in which the material to be treated is in open-width form (i.e., in the form of a single-layered web). However, notwithstanding its many potential advantages, continuous dyeing has not been applied successfully, heretofore, to the treatment of tubular knit fabrics, although the industry has attempted for many years to develop commercially practicable methods to do so.

In large part, at least, tubular material has been incapable of being successfully continuously dyed, theretofore, by reason of an inability to obtain uniformity of dyeing, and hence of color, throughout the entire extent of the tubular material. Specifically, tubular material is normally treated in flattened, two-layered form, which gives rise to substantial problems in connection with uniform penetration of the dye, particularly at the edges of the material. Thus, continuously dyed tubular material has been characterized, heretofore, by edge marks, or areas at the edges of the tube where the coloring is either lighter or darker than over the remaining area. Such edge marks render the material unsuitable for commercial use, as they result in unwanted continuous lines or streaks in a lengthwise direction along the edges of the fabric tube. And while these streaks are initially at the edge, which in itself is very undesirable, further processing of the tubular fabric causes the streaks to appear at any point in the finished fabric, because of fabric reorientation, which creates new edges, and this is wholly intolerable. Moreover, with tubular fabric, both sides or surfaces must be absolutely uniform as regards color shading since, as mentioned, the two principal sides of the fabric may and usually will be reoriented during further processing.

In accordance with the present invention, novel arrangements are provided for delivering, in a continuous, controlled process, a commercially acceptable dyed tubular knitted fabric, free of so-called edge marks, color variations on opposite sides, and other common defects. To this end, the invention provides an improved apparatus for treating tubular knitted fabric, whereby the material is penetrated uniformly and thoroughly by the dye liquor on both principal layers of the fabric tube and at the doubled-over edges, whereby edge mark-s, color variations on opposite surfaces, and other defects, at the edges or folds of the material or elsewhere, are effectively eliminated.

Generally stated, the method of the invention involves the first important step of laterally distending the tubular ice knitted fabric and setting it to predetermined width. The uniformly set fabric is then submerged in a bath of dye liquor and there subjected to a succession of squeezings under concentrated pressure. During the squeezings, the fabric is maintained continuously and wholly submerged in the dye bath, and the opposite sides of the fabric are alternately exposed to the dye liquor. At the same time, the generally elastic and dimensionally unstable fabric is maintained under constant dimensional control to provide uniform fiber and stitch conditions, which promotes uniform penetration and acceptance of the dye. The succession of submerged squeezings is such in number and character as to reliably assure complete and uniform dye penetration, even at the doubledover edge portions of the fabric tube. The thus uniformly and thoroughly impregnated fabric is immediately thereafter, and while being maintained under complete dimensional control, passed through a resilient nip to reduce the dye liquor content to a predetermined uniform level.

As one of the more specific but significant aspects of the invention, the tubular knitted fabric is directed into a dye bath and passed through a series of concentrated pressure nips for successively squeezing and releasing the fabric a plurality of times while the fabric remains wholly submerged in the dye bath and under continuous dimensional control. Immediately thereafter the fabric is passed through a lower pressure nip, which controllably limits the amount of uniformly penetrated dye liquor to be retained in the fabric. Throughout the treating sequence, advantageously from the first to the final pressure nip, the normally elastic and easily distortable fabric is maintained continuously in control contact with dimensionally stable surfaces, so that the internal structure and geometry of the fabric is kept uniform, as is the ability of the fabric to receive and retain dye uniformly. Further, during the successive, submerged squeezin-gs of the fabric in submerged pressure nips, opposite sides of the tubular fabric are alternately exposed to the dye bath (one side always being in contact with a surface) so that desired uniformity of dye penetration from either side is obtained.

As a further specific feature of the invention, the submerged nips advantageously are comprised of cooperating pairs of non-resilient rollers capable of applying concentrated nip pressures to the submerged tubular knitted fabric. The sets of rollers are so arranged, according to the invention, that alternate (intermediate) rollers are urged uniformly into concentrated pressure contact with two adjacent rollers in a way that assures substantial uniformity of the successive concentrated nip pressures.

Advantageously, means are provided whereby the tubular fabric is directed downwardly into the dye bath and is passed through a first submerged, concentrated pressure roller nip, while still moving in a downward direction. The roller nip completely closes the tube and prevents the entrapment of air inside the fabric tube. The sponge-like action, realized as the fibers are squeezed and subsequently released in the submerged, concentrated pressure nips, assures thorough elimination of air from the fibers and thorough and uniform penetration of the fibers by the dye liquor.

Another specific feature of the invention resides in the provision, in combination with novel facilities mentioned for imparting a uniformly penetrated excess of dye, of im- I proved, resilient roller means forming a lower, controlled pressure nip at the exit end of the dye station. As the material emerges from the dye bat-h, it is passed directly and while still under dimensional control through the nip formed by the resilient rollers, whereby excess dye is removed from the material in a uniform and desirable manner. In this respect, it has been found that the non-resilient rollers.

nature of the surfaces forming the resilient nip may be an important factor, since edge marks may result if the roller surfaces are too soft or too hard.

A further important feature of the invention resides in the provision, in means generally as above described for continuously dyeing fabrics, of improved arrangements for uniformly preconditioning the fabric prior to its passage through a dye station, to the end that the fabric entering the dye station is uniformly conditioned as to temperature and water content, so that all portions of the fabric may be acted upon uniformly by the dye. In the treatment of wet goods, for example, the material entering and continuously passing through the dye bath has a relatively short period in which to be acted upon by the dye, and various non-unitormities in the goods will show up as color imperfections in the dyed material. Accordingly, the present invention provides for the continuous treatment of the goods, prior to dyeing, to render uniform the water content thereof. Advantageously, this is accomplished in a manner and by an apparatus similar to that used in the actual dyeing of the goods. Thus, the material is passed in a downward direction into a water bath, through a series of submerged concentrated pressure n-ips advantageously formed by contacting, friction-driven, Immediately thereafter the fabric is passed through a pair of extracting rollers. While passing through the submerged nips, the fabric is subjected to a series of high pressure squeezing and releasing actions, whereby the fabric takes up a uniform excess of Water. The excess water is thereupon removed by the extracting roller, whereby the emerging material contains a uniformly distributed, predetermined quantity of Water and is conditioned to accept the dye liquor uniformly.

The invention also provides for the preconditioning of wet material by causing it to absorb, prior to dyeing, a uniform quantity of water at a temperature which approximates or exceeds that of the dye liquor itself. Accordingly, the material entering the dye bath is as close as practicable to the controlled temperature of the dye liquor. This is an important factor in the achieving of high quality, uniform dyeing of wet goods on a continuous basis, since dye penetration is affected by temperature and non-uniformities may be expected where constant conditions do not prevail.

In the treatment of wet goods, as in the treatment of substantially dry goods, the fabric is caused to have uniform dimensions and conditions during the preconditioning water treatment, to assure uniformity of water penetration and absorption. To this end, the material is laterally distended or spread to a predetermined width and uniform condition, prior to entry into the treating bath, and this condition is carefully maintained during passage of the material through the treating bath by reason of constant contact of the material with surface portions of the non-resilient friction-driven rollers. The preconditioned material emerging from the water bath is again set to predetermined width or, where advantageous or expedient, the material may be directed immediately into the dye bath while maintaining the uniform conditions of width and tension, etc.

The teachings of the invention are also applicable to advantage in connection with the treatment of materials in successive stages, where the first stage, or perhaps an intermediate stage, is not a water treatment but is a treatment with active solution. Thus, in conjunction with a dyeing treatment, it may be desirable to precondition the material uniformly with a penetrant or other pretreatment solution. 'Further, it may be desirable and advantageous to carry out the dyeing operation in two or more distinct stages, either with or without a step involving water or other preconditioning solution.

In connection with the treatment of dry materials, the invention provides for preconditioning of the material by steaming the material while distending it to uniform width,

prior to entry of the material into the dye bath or into a preconditioning water bath. By thus steaming the material, while distendin-g it to predetermined, uniform width, the material is not only rendered highly uniform in structure and therefore capable of uniformly accepting the dye or preconditioning bath, but is uniformly conditioned from the standpoint of heat and moisture content, which aids importantly in bringing about uniformity of dye penetration. The material may also be spread to an extra wide width to enable the rate of dye penetration to be increased.

For a better understanding of the invention, and for a further discussion of the above and other novel and advantageous features thereof, reference should be made to the following detailed description and to the accompanying drawings, in which:

FIG. 1 is an elevational view of an apparatus incorporating the invention and for use in carrying out the method of the invention; I

FIG. 2 is a top plan view of the apparatus of FIG. 1;

FIG. 3 is an enlarged, fragmentary, cross-sectional view taken generally on line 33 of FIG. 2; and

FIG. 4 is a simplified schematic representation of a processing line, incorporating apparatus as illustrated in IFIG. 3, for treating wet goods.

Referring now to the drawings, the reference numeral 10 designates, generally, a representative form of combination spreader and propelling device, which may be of the type described in the S. C-ohn et a1. United States Patent No. 2,385,402, for example. The spreader 10 is positioned to receive tubular material from a prior processing station, as part of a continuous process, and uniformly conditions the material and distends it laterally to a predetermined width. The spreader also advances the material toward a dyeing station, designated by the reference numeral 11. The material received by the spreader 10 may be bleached or secured, and may be in either wet or dry form. If the material is in dry form, it is advantageous to provide steamers 12 in association with the spreader 10, so that the material is steamed in connection with the operation of distending it to a predetermined width. The steaming not only sets the fabric in its distended form and enables the material to be rendered structurally uniform, but also heats it uniformly and imparts uniform moisture thereto, all of which importantly alfect the uniformity of dyeing. It is uniformly necessary, of course, for the fabric to be presented to the dye bath in fiat form and in a uniform, geometric condition.

If the fabric is taken directly from a bleaching operation, for example, and is in wet form, a pair of squeegee rolls 13 may be provided to remove as much of the residual treating liquids as possible from the material after it is passed over the spreader 10. Where the material is received in wet form, the steamers 12 usually may be omitted, but they may be utilized to advantage in elevating the temperature of the fabric. By spreading the wet material to a predetermined, uniform width, the various tensions in the material are rendered substantially uniform, enabling dye penetration to be effected with desired uniformity, as will be described.

The illustrated spreader device 10 consists of a pair of belts 14, 15 supported within the fabric tube by a frame 16 and driven by a pair of edge rolls 17, 18. The frame 16 may be adjusted to a predetermined width, to stretch the fabric width-wise to a predetermined extent, and the fabric is propelled forward over the spreader by means of the belts 14, 15 driven by the edge rolls 17, 18. In the illustrated arrangement, the speed of the fabric on opposite sides of the edge rollers 17, 18 is the same.

In the treatment of dry fabric, the fabric is subjected to steaming, by means of the steamers 12, while on the. spreader 10. This lubricates the fibers of the material and enables them to reorient as necessary. Such lubrication is not required, of course, where the spread material is wet from prior treatments, such as bleaching, etc. In addition, the steamers uniformly condition the material with respect to temperature and moisture content.

In the form of the invention shown in FIGS. 1-3, the fabric travels from the spreader to a dye bath maintained in a reservoir 19. If wet fabric is treated, the fabric is passed between the squeegee rollers 13, during its travel between the spreader and the dye bath, so that excess water or other liquid is removed from the material and a desired liquid content in the material is achieved. The fabric thus conditioned is immersed in the dye bath and subjected therein to an action resulting in the thorough and uniform penetration of the dye, in a manner to be described.

Referring now to FIG. 3, the reservoir 19 of the dye ing apparatus is supported on a frame 20 and provided with an overflow pipe 21, which, in combination with appropriate dye inflow means (not shown), maintains the dye bath 22 at a predetermined level. Advantageously, a constant, circulating inflow of dye liquor is provided to assure uniformity of the dye mixture as well as to maintain the dye at a precise, predetermined level in the reservor. Uniformity of the dye level is considered to be a factor of prime significance in the obtaining of uniform dyeing results.

The fabric F travels over the dye bath 22, at the entry or right hand side thereof and passes over a guide roller 23 mounted in a frame 24 at a level such that at least part of the roller is exposed above the level Otf the bath.

Mounted in the frame 24, below the level of the bath, are non-resilient pressure rollers 25, 26, which advantageously are arranged to rotate freely in the frame. Spaced above and to the left of the pressure rollers 26, so as to be only partly immersed in the dye bath 22, is an extracting roller 27 which advantageously is of relatively large diameter and has a surface covering 28 of resilient material, as will be described. The roller 27 is mounted in the frame 24 and is connected to suitable drive means D (FIG. 2).

As illustrated in FIG. 3, the

rollers

25, 26 and 27 are arranged somewhat in a line, and each is spaced a predetermined distance from the adjacent roller or rollers. Mounted below the rollers 25-27 and positioned generally in the spaces between those rollers are non-resilient pressure rollers 29, 30, which advantageously are the same diameter as the pressure rollers 25, 26, which diameter is somewhat larger than the spaces between the

rollers

25, 26 and 26, 27.

In accordance with one specific aspect of the invention, the pressure rollers 29, 30 are suspended at their opposite ends by arms 31, 32, which are pivotally connected to a yoke 33 at points 34, 34'. The yoke 33 is, in turn, connected to control means, such as a lever 35, by a pivot 36 located substantially centrally between the

pivots

34, 34. The lever is pivoted at 37 on the main frame 24 and has mounted at one end a hand lever 38, for example, by means of which the lever 35 may be manipulated. The hand lever 38 cooperates with a bracket 39 having therein a plurality of notches 40 which receive the hand lever 38 and lock it in any of a plurality of positions.

By appropriate manipulation of the hand lever 38, the rollers 29, 3% may be moved toward and away from the pressure rollers 25-27. Thus, to thread the fabric F through the machine the hand lever 38 is moved forward to lower the pressure rollers 29, 30. The fabric F is then threaded first between the rollers 25, 29, next between rollers 29, 26, then between

rollers

26, 30 and, finally, between

rollers

30, 27. The hand lever 38 is then drawn rearwardly and engaged in one of the notches 40. The rollers 29, 30 are thereby drawn tightly against the rollers 25-27, forming therewith a plurality of submerged roller nips through which the fabric passes. By suspending the yoke 33 centrally between the pivot points 34, 34', it is assured that the rollers 29, 30 will engage the rollers 25-27 with uniform pressure, so that each of the several roller nips formed by the roller pairs 25 and 29, 29 and 26, and 26 and 30 is substantially the same as regards nip pressure. Advantageously, the hand lever 38 is formed of steel rod, for example, providing for a certain measure of springiness or yield. Accordingly, once the rollers 29, 30 are brought into engagement with the rollers 25-27, the nip pressure may be regulated by deflecting the hand lever 38 and locking it in a deflected position by means of the notched bracket 39.

In accordance with one of the specific aspects of the invention, the first pressure nip, through which the fabric F is passed substantially immediately after it enters the dye bath 22, is so oriented that the fabric passes through the nip while moving in a generally downward direction. In the illustrated apparatus, the first submerged pressure nip is formed by the non-resilient rollers 25, 29 and the fabric F passes directly to this nip from the guide roller 23. The arrangement of the first nip in this manner is advantageous in that the fabric is squeezed flat under forcible pressure to displace any air which may be trapped within the tube. Generally, a relatively large volume of air is expelled from the material at the first nip and it is important to release the air from above the nip to facilitate escape of the air, as indicated by the series of bubbles at 4 1. Otherwise, the air is apt to become trapped within the fabric tube.

As the fabric passes through the series of submerged nips, including the first nip, the fabric is compressed forcibly and with highly concentrated pressure by the

nonresilient rollers

25, 26, 29, 30, so that air and liquid is thoroughly forced out of the fibers in an effective and uniform manner. As the fabric emerges from each pressure nip, the concentrated nip pressure is suddenly released from the fabric and the dye liquor is drawn into the fibers to replace the air and liquid expelled therefrom during passage through the nip. This results in a spongelike action in the fabric, whereby air and liquid are repeatedly and thoroughly expelled under concentrated nip pressure from the fabric and dye liquid is then drawn back into the fibers to penetrate all portions of the fabric in a highly effective and uniform manner.

In accordance with one of the significant aspects of the invention, the fabric traveling through the series of submerged, concentrated pressure nips formed by the

nonresilient rollers

25, 26, 29, 30 is at all times maintained in edge-to-edge control contact with at least one of the rollers. Accordingly, the tubular knit fabric, which is inherently elastic in character and easily distorted, is effectively retained in its original dimensions, preventing gathering and wrinkling of the fabric and assuring maintenance of the uniform tension conditions in the yarns of the fabric. In this respect it is a feature of the invention that the tubular knit fabric is maintained constantly under dimensional control from the point of its entry into the first concentrated pressure nip, formed by rollers 25, 29, to the point of emergence of the dyed fabric from the extraction nip, constituting the last instance of working of-the fabric during the dyeing process. Advantageously, this is accomplished by maintaining the fabric in edgeto-edge control contact with roller surfaces throughout. By this means, the unstable, easily distortable fabric is maintained reliably and controllably uniform throughout the working of the fabric in the presence of the dye liquid, so that conditions are proper for uniform acceptance of the dye by the fabric.

In addition, and as another important facet of the invention, the tubular knitted fabric traveling through the series of concentrated pressure working nips has its opposite sides alternately exposed to the dye liquid. In this respect, the opposite surfaces of tubular knitted fabric in process do not represent front and back, as is the case with woven fabrics and other materials handled in open width form, but both the top and bottom surfaces are outside surfaces of the finished fabric. As a result, unless both surfaces are dyed to an identical shade, the finished product is inferior, if not useless. Thus, in the system of the invention, the concentrated pressure working nips, and the non-resilient rollers forming them, are wholly submerged in the dye liquid so that, as the fabric passes through the nips in sequence, with one surface always in contact with a roller, the opposite sides of the fabric are alternately exposed to the dye bath.

In the illustrated form of the invention, the covered roller 27 is driven by the drive means D, and the

rollers

25, 26 and 29, 30 are driven at corresponding peripheral speeds by reason of the frictional contact between the series of rollers and the fabric passing between the roller nip. In this manner, lengthwise tensions on the material, which might otherwise change in passing the material through one or more roller nips, are maintained at a highly uniform level.

In accordance with the invention, the successive high pressure squeezings of the uniformly conditioned material, as it passes through the successive, submerged working nips in the dye bath, are such, in number and effectiveness, as to penetrate the fabric uniformly with an excess of the dye liquor. Moreover, and particularly as a result of working in non-resilient submerged nips, the extreme edge portions of the fabric, where the material curves around from one flat plane to another, are thoroughly penetrated by an excess of dye, and this constitutes an important accomplishment of the invention as it enables the finished product to be free of edge marks characteristic of material attempted to be dyed continuously by known procedures and with known equipment.

After the fabric F has passed through the series of submerged working nips formed by the rollers 2527, 29, 30, the fabric travels upward, around the surface of the partly submerged roller 27, and through an extracting nip 42 formed by the roller 27 and a similar roller 43 located directly above. The

rollers

27, 43 are provided with

coverings

28, 44 of resilient material, advantageously rubber, and, as the fabric passes through the nip 42, pressure is applied by the

rollers

27, 43, to extract excess dye uniformly from the fabric, leaving a uniform, predetermined amount of the dye in the fibers.

In accordance with one aspect of the invention, the operation of extracting the excess dye from the fabric is carried out in a manner calculated to assure uniformity of dye coloring throughout the entire area of the fabric, including its edges. At the extreme edges of the fabric, the material curves around, and narrow strips at the extreme edges of the material may not be acted upon by the extracting rollers in the same manner as the flat surfaces of the fabric. However, we have found that, by imparting to the surfaces of the

rollers

27, 43 the proper degree of resilience, so that the rollers are neither too soft nor too hard, the extracting step may be carried out with substantial uniformity throughout all areas of the material, avoiding edge marks and other defects. Specifically, it has been found that superior results are achieved by providing the

rollers

27, 43 with

surface coverings

28, 44 formed of rubber having a density approximating 72 durometer. It is anticipated that the operative range of rubber density would extend somewhat above and below 72 durometer, but it is presently believed to be important, insofar as the extracting operation is concerned, to utilize rollers having surface characteristics similar to those of rubber whose density is in the range of 72 durometer. Of course, it is necessary to the realization of proper results in the extracting stage that the fabric previously be thoroughly and uniformly impregnated with dye liquid, as by the described series of high pressure working nips, and that the dimensional uniformity and control of the fabric be maintained until completion of the extracting action at the nip 42. Thorough dye penetration in excess quantities, reliably achieved as in accordance with the invention, materially improves the prospect of carrying out the extracting operation in a manner such that the finished product is free of edge marks, etc.

One of the advantageous aspects of utilizing extracting rollers having relatively resilient surfaces is that, due to deformation of the surface material, the nip 42 is relatively broad, in a direction lengthwise of the fabric. This assures thorough extraction of the excess dye, as well as a sustained uniformity of action on the material. In addition, the characteristics of the surface material of the extracting rollers have a substantial effect on the treatment of the material at the extreme edges. Thus, if the extracting rollers have hard surfaces, the material will be subjected to increased pressure at the extreme edges while, if the surface material is too soft, it may deform and close about the edges of the material to an undesirable extent. In either case, undesirable edge marks on the material will result.

The pressure at the extracting nip advantageously is controlled in a relatively precise manner by mounting the upper roll 43 on a lever 45 pivoted on the frame 24 by means of a pin 46. The free end of the lever 45 may have attached thereto a suitable spring device 47, for example, capable of relatively precise adjustment, so that the extracting roll pressure may be adjusted in an accurate manner. A typical adjusting arrangement suitable for this purpose is illustrated in the S. Cohn et al. United States Patent No. 2,729,003, for example.

After the fabric F leaves the dye bath and passes through the extracting nip 42, subsequent treatments usually are applied, depending on the nature of the dyeing or processing. For example, where direct dyes are used, the fabric usually is directed to a salt bath, to salt in the color, then to a rinse and perhaps to other treating stations including, for example, a softening bath. The material may then be dried and cured or otherwise treated, as may be desired.

The method and apparatus above described are particularly useful in the treatment of dry fabrics (using the steamers 12) and may be used successfully in the treatment of wet fabrics (using the squeegee rollers 13). However, for controllably superior results in the treatment of wet tubular knitted fabrics, the invention, as one of its important aspects, contemplates the provision of arrangements for uniformly and controllably preconditioning the fabric, prior to dyeing, enabling the dyeing operation itself to be carried out with desired, superior uniformity.

In this respect, it has been found that, in continuous dyeing of wet fabric, where the material has a relatively short period of exposure to the dye liquor, precise uniformity of water content of the fabric is important to the achievement of uniformity of dyeing. Thus, whereas the system of FIG. 1 may be adequate for the treatment of wet material whose starting or initial water content is fairly uniformly excessive, such relatively ideal conditions may not be present always and the treatment may have to be carried out with material which is wet, but not containing either a uniform or an excess quantity of water, or with dry material which it is desired to wet prior to immersion in the dye bath.

Referring now to FIG. 4, there is shown a processing line especially arranged, in accordance with the invention, for the treatment of wet tubular knitted fabric in a manner to achieve reliably superior, uniform dyeing of wet material on a continuous basis. The starting material 50 may be in wet form, as received from prior processing operations, such as bleaching and subsequent, related treatments, and the material in this form is, in accordance with the invention, passed over a spreader 51, which may correspond in construction and operation to the spreader 10 of FIG. 1. While passing over the spreader 51, the fabric 50 is distended to a predetermined uniform width, and desired, uniform conditions of tension are imparted to the material.

Advantageously, as the fabric leaves the exit side of the spreader 51 it is passed between squeegee rollers 52, which remove a substantial amount of excess liquid from the material. This usually is desirable, since the liquid contain-ed in the fabric may contain chemicals from prior treatments, whose presence in the material in substantial quantities may undesirably affect the further treatment thereof. If the liquid initially in the fabric is plain water, the squeegee rollers 52 may not be required.

After the material 51 has been spread, and has passed through the squeegee rollers 52, if used, it is directed into an impregnation unit 53 containing water or other pre-treating solution. The unit 53 advantageously is of the same construction as the dyer unit 11, of FIGS. 1-3, the principal difference residing in the fact that the liquid contained in the reservoir is water or other pretreating solution rather than dye liquor. The fabric passes downward into the solution and successively through a series of wholly submerged high pressure working nips formed by contacting, friction-driven, non-resilient rollers, all as clearly indicated in FIG. 3. At each working nip, solution and air are forcibly expelled from the fabric and, as the material emerges from a nip and is released by the roller, solution is drawn back into the material, thoroughly penetrating the fibers of the material. By reason of the successive squeezing and releasing actions under concentrated pressures while the fabric remains submerged in the solution, a uniform excess of the solution penetrates the entire body of a material.

As the fabric traveling through the solution is subjected to a sponge-like action by successive squeezing and releasing operations, it is maintained in continuous contact with rollers so that the fabric does not tend to narrow down from its preset width. Moreover, as before described, the various rollers forming the submerged nips are driven by frictional contact with each other, through the interposed material, so that tensions in the material are not varied during the course of travel through the solution.

Material emerging from the pre-treating solution is uniformly impregnated with an excess quantity of solution, and this material is passed through extractor rollers 54, corresponding to the

rollers

27, 43 of FIG. 3 and forming part of the impregnation unit 53. The action of the rollers 54 is such as to extract from the material the excess quantities of solution, leaving a predetermined, uniform quantity precisely suited for subsequent dyeing of the material.

In accordance with one aspect of the invention, the solution in the unit 53 is maintained at or above the temperature of the dye bath, to the end that the wet material ultimately entering the dye bath is substanially at the temperature of the dye liquor. This is of special importance in the continuous dyeing of wet materials, since non-uniform results would be realized if cold wet fabric were introduced into the dye bath, particularly since there is only a short period of time in which to reach equilibrium temperature conditions while the material mov-es rapidly through the bath. Generally, the pre-treating solution (as the dye bath) is maintained at a predetermined tempenature, and suitable heating means, not specifically shown, are provided for this purpose.

In the system illustrated in FIG. 4, the solution-impregnated material leaving the unit 53 is passed over a second spreader 55, which may be of the type before described. This spreader re-establishes precise geometric control over the fabric. And, if desired, the material may be set at some other width calculated to provide a desired level of uniform tension for dyeing.

In certain cases, where adequate geometric control of the fabric is otherwise maintained, the second spreader may be eliminated altogether, and the solution-impregnated material taken directly into the dye bath from the extractor rollers 54.

The impregnated and otherwise preconditioned material, after spreading if the unit 55 is employed, is directed into a dyer apparatus 56, which, for the purpose of this description, may be similar in all material respects to the dyer unit show-n in FIG. 3. The wet material entering the dye bath maintained in the unit 56 is, among other things, heated substantially to the temperature at which the dye bath is maintained which, in some cases, is near boiling. Suitable heating means, not specifically shown, are of course provided in association with the unit 56, as well as the unit 11 of FIG. 1, to maintain the dye bath at the desired temperature.

Dyeing of the preconditioned, wet material in the unit 56 takes place substantially in the manner before described in connection with the system of FIGS. 1-3. The emerging, dyed material is highly uniform in nature, free of edge marks and otherwise of high quality character.

In a system, such as shown in FIG. 4, the material may be subject to two or more distinct treatment steps. In many instances, at least one of such steps will be a Water pretreatment step, but it may be advantageous to carry out a plurality of separate treatment steps with or with out an additional water pretreatment step. Certain dyes, for example, are typically applied in a two stage process, and the system of the invention may be utilized to carry out such a two stage process as part of a continuous operating line.

In connection with the treatment of dry goods, it is particularly important to precondition the material by spreading it to uniform, predetermined width and steaming it while thus spread to impart stabilized structural uniformity thereto. Spreading of the material is also important in the case of wet material, to set the material to predetermined width and to render it structurally uniform, but steaming of the Wet material normally is not required.

The new method represents a substantial advance in the art, by providing a method of dyeing tubular knitted fab-ric continuously to produce commercially acceptable dyed tubular knitted fabric free of edge marks. Thus, bleached or scoured fabric, taken in either a wet or dry state, may be passed continuously, in the form of a flat web of doubled material, through the dyeing apparatus and directly to the subsequent processing stations, such as the salt bath and rinse, for example. Heretofore, it has been deemed impossible to dye tubular knitted material on a continuous basis in a competitive manner productive of commercially acceptable finished fabric free of edge marks, notwithstanding that continuous dyeing has been done successfully for many years with woven fabrics. With the method and apparatus of the invention, however, the various difficulties have been overcome in a manner assuring thorough and uniform penetration of the fibers by the dye liquor, followed by uniform extraction of excess dye.

One of the particularly important aspects of the invention resides in the working of the tubular knitted fabric through a contacting series of wholly submerged, nip rollers capable of applying substantial concentrated working pressures to the fabric. The arrangement is such that the tubular knitted fabric is subjected to a succession of high pressure squeezing operations, to displace liquid and air, followed by a quick release of the concentrated squeezing pressure, to cause the fabric to draw the dye liquid thoroughly into all of its fibers. The utilization of non-resilient rollers to form the series of working nips is of particular advantage, in that it enables the working pressure to be highly concentrated at the submerged working nip. This enables the fabric, in passing through a series of such high pressure nips, to absorb a uniform excess of the dye liquida condition which has been heretofore unattainable in a practical continuous operation with tubular knitted fabrics.

In conjunction with the utilization of a succession of high pressure working nips, the rollers forming the working nips are arranged in a contacting series, so that at least one surface of the tubular knitted fabric is at all times in edgc-to-edge control contact with a dimenisonally stable roller surface. Thus, the geometric conditions of the inherently elastic and unstable tubular knitted fabric are, to the greatest practicable extent, maintained uniform and under effective control. This is particularly important to enable the tubular knitted fabric to accept the dye liquid in a uniform manner and is a factor which, prior to our invention, has not been adequately recognized and appreciated. Specifically, it is a feature of this invention that the tubular knitted fabric is maintained under dimensional control from the point of its initial entry into the first submerged working nip to the point of its emergence from the extracting nip, advantageously, by continuous edge-to-edge contact with roller surfaces. Accordingly, all of the working operations performed on the tubular knitted fabric in the presence of the dye liquid are performed while the fabric is maintained geometrically stabilized.

As a further specific aspect of the invention, the tubular knitted fabric, while passing through the series of submerged working nips and while having one surface maintained in control contact with a dimensionally stable roller surface, has its opposite sides alternately exposed to the dye liquid. In this respect, it was recognized that the ability of the fabric to absorb the dye liquid in the region of the surface thereof in contact with a dimensionally stable roller surface may be limited relative to the opposite surface. Accordingly, provisions are made in accordance with the invention to cause first one side and then the other of the fabric to be in control contact with a roller surface, as the fabric progresses through the series of submerged working nips. The alternately noncontacting surfaces of the fabric thus are exposed successively to the dye liquid so that, in the course of the submerged working of the fabric, both sides of the fabric are exposed to the dye liquid.

The various aspects of the present invention particularly recognize and accommodate the fact that all of the exposed surfaces of a tubular knitted fabric constitute outside surfaces of the finished fabric, as distinguished from the typical woven fabric, for example, in which one surface is the outside and one surface is the inside. Thus, in the dyeing of tubular knitted fabric, it is absolutely essential that both the top and the bottom, and also the edge extremities, assume exactly identical dye shades. Any shade differential between sides, or any marks or lines along the edge extremities, will render the fabric practically worthless, since the consumer obviously desires color uniformity in the final garment. This is particularly true in view of the fact that the edges of the fabric during the dyeing operation may not be the edges of the fabric at a later stage in processing, so that a shade differential line or an edge mark may ex tend along a principal fiat surface of the finished fabric tube.

A significant achievement of the present invention is the ability to impart to the tubular knitted fabric, during its continuous passage through a dye bath, a uniform excess of the dye liquid in all of the fibers and yarns of the fabric, including the edge extremities and including the top surface to the same extent as the bottom surface. This greatly reduces the criticality of the subsequent extracting operation, by which the excess dye is removed from the fabric to achieve a high quality, uniform product. A further significant achievement resides in the ability to achieve thorough, uniform penetration in a relatively short course of fabric travel, so that the setto-width and geometrically stabilized fabric tube may be maintained under geometric control throughout.

The most important ultimate advantage of the new method and apparatus results from the fact that the dye station may be incorporated in a continuous tubular knitted fabric processing line, so that the fabric may be subjected to an entire series of processing operations on a high-speed, continuous basis. Heretofore, dyeing of tubular fabric has been carried out on a batch basis, usually by placing lengths or strings of the fabric in a dye vat. This has involved an interruption of the processing sequence and has, in addition, involved additional operating steps in preparing the fabric for the dye vat and subsequently conditioning it for further continuous processing.

It should be understood that the specific method and means herein illustrated and described are intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

We claim:

1. Apparatus for continuously and uniformly impregnating tubular knit fabric with a dye liquid to provide dyed tubular knitted fabric free of edge marks, which comprises (a) a reservoir for maintaining a bath of the liquid at a predetermined level,

(b) means adjacent the entry end of the reservoir for guiding the tubular fabric and presenting it in flat form into the bath,

(c) a plurality of pressure rollers below the surface of the bath and forming a succession of submerged nips arranged successively to receive and apply concentrated pressure to the fabric,

(d) said pressure rollers being wholly submerged in said bath, whereby said fabric remains continuously and wholly submerged in said bath while passing through said succession of submerged nips,

(e) the succession of submerged nips comprising a plurality of non-resilient rollers forming concentrated pressure nips,

(f) certain of the non-resilient rollers being mounted for rotation on normally fixed axes and being spaced from each other,

(g) the remainder of the non-resilient rollers being controllably and forcibly movable into and out of the spaces formed between the fixed rollers,

(h) the movable rollers being suspended at each end by pairs of support arms,

(i) the support arms being pivotally secured to yokes at opposite ends of the rollers,

(j) the yokes being mounted for pivoting movement about axes substantially centrally between the pivot axes of the support arms,

(k) means being provided for controllably moving the pivot axes of the yokes toward and away from the normally fixed rollers, and

(1) an extracting nip mounted adjacent the exit end of the reservoir and above the level of the bath and comprising a pair of extracting rolls having resilient outer surfaces,

(m) said pressure rollers being mounted in a contacting series, whereby the fabric is caused to be in edge-to-edge control contact with a dimensionally stable surface while passing through said submerged nips.

2. Apparatus for continuously and uniformly impregnating tubular knitted fabric with a dye liquid to provide 60 dyed tubular knitted fabric free of edge marks, which comprises (a) means forming a reservoir for the dye liquid,

(b) liquid level control means for maintaining a bath of the dye liquid at a predetermined constant level in said reservoir,

(c) means adjacent the entry end of the reservoir for engaging and guiding the tubular knitted fabric, distending it laterally to fiat two-layer form and to predetermined uniform width, and substantially directly presenting the fabric in flat two-layer form into the bath of dye liquid,

(d) a plurality of pressure rollers forming a succession of submerged squeezing nips arranged successively to receive and apply concentrated squeezing pressure to the tubular knitted fabric,

(e) said pressure rollers being disposed in said reservoir and at a level such that at least alternate ones of the pressure rollers and all of said squeezing nips are below the predetermined constant level of said liquid level control means,

(f) means effective to drive said pressure rollers in a direction to guide and advance said tubular knitted fabric about said pressure rollers and through said squeezing nips while maintaining said tubular knitted fabric continuously and uninterruptedly below the predetermined constant level of said liquid level control means and therefore submerged in said dye liquid,

(g) an extracting nip located adjacent the exit end of said reservoir and above the level of said liquid level control means and comprising a pair of extracting rolls having resilient outer surfaces,

(h) means mounting one of said extracting rolls above the other,

(i) means mounting the lower one of said extracting rolls at a level such that at least part, but less than all, of its surface is below the predetermined constant level of said liquid level control means and therefore submerged in said dye liquid,

(j) said lower extracting roll and the last one of said pressure rollers being so mounted and disposed that transference of said tubular knitted fabric from said last pressure roller into contact with said lower extracting roll is effected below the predetermined constant level of said liquid level control means and while said fabric remains continuously and uninterr-uptedly submerged in said dye liquid,

(k) means supporting said pressure rollers in a contacting series disposed and arranged to guide and direct said tubular knitted fabric sinuously about said rollers to expose the opposite layers of the fabric alternately to the dye bath, and

(1) means comprising said pressure rollers for guiding and directing the tubular knitted fabric continuously and uninterruptedly in edge-to-edge dimension stabilizing contact with dimensionally stable roller surfaces at all times while passing through said submerged squeezing nips, from at least the first to the last such submerged nip.

3. An apparatus according to claim 2, further characterized by (a) the partially submerged lower one of said extracting rolls being mounted in pressure contacting relation with one of said pressure rollers,

(b) external drive means being provided for rotating said partially submerged extracting roll,

(c) the other of said extracting rolls and said pressure rollers being driven from said partially submerged extracting roll and through interposed layers of tubular knitted fabric passing through said squeezing and extracting nips.

4. Apparatus for continuously and uniformly impregnating tubular knitted fabric with a dye liquid to provide dyed tubular knitted fabric free of edge marks, which comprises (a) means forming a reservoir for the dye liquid,

() means immediately adjacent the entry end of the reservoir for laterally distending the tubular knitted fabric and presenting it in flat two-layer form and at a predetermined uniform width to the bath of dye liquid and guiding and directing it downwardly into said dye liquid,

(d) a plurality of pressure rollers forming a sucession of submerged squeezing nips arranged successively to receive and apply concentrated squeezing pressure to the tubular knitted fabric,

(c) said pressure rollers being disposed in said reservoi-r and at a level such that at least alternate ones of the pressure rollers and all of said squeezing nips are below the predetermined constant level of said liquid level control means,

(g) the pressure rollers forming the first of said squeezing nips being mounted and arranged in said reservoir to receive the presented tubular knitted fabric traveling in a downward direction into said bath to accommodate expulsion and upward escape of air from the fabric as the fabric tube is closed and squeezed in said first nip,

(h) an extracting nip located adajacent the exit end of said reservoir and above the level of said liquid level control means and comprising a pair of extracting rolls having resilient outer surfaces,

(i) means mounting one of said extracting rolls at a level such that at least part, but less than all, of its surface is below the predetermined constant level of said liquid level control means and therefore submerged in said dye liquid,

(j) said one extracting roll and the last one of said pressure rollers being so mounted and disposed that transference of said tubular knitted fabric from said last pressure roller into contact with said one extracting roll is effected below the predetermined constant level of said liquid level control means and while said fabric remain-s continuously and uninterruptedly submerged in said dye liquid,

(1) means comprising said pressure rollers for guiding and directing the tubular knitted fabric continuously and uninterruptedly in edge-to-edge dimension stabilizing contact with a dimensionally stable roller surface at all times while passing through said submerged squeezing nips, from at least the first to the last such submerged nip.

5. Apparatus for continuously and uniformly impregnating tubular knitted fabric with a dye liquid to provide dyed tubular knitted fabric free of edge marks, which comprises '(a) means forming a reservoir for the dye liquid,

( b) liquid level control means for maintaining a bath of the dye liquid at a predetermined constant level in said reservoir,

(c) means adjacent the entry end of the reservoir for presenting laterally distended tubular knitted fabric in flat two-layer form and at a predetermined uniform width to the bath of dye liquid and guiding and directing it downwardly into said dye liquid,

(d) a plurality of relatively small diameter, substantially non-resilient pressure rollers forming a succession of submerged squeezing nips arranged successively to receive and apply concentrated squeezing pressure to the tubular knitted fabric,

(e) said pressure rollers being disposed in said reservoir and at a level such that at least alternate ones of said pressure rollers and all of said squeezing nips are below the predetermined constant level of said liquid level control means,

(-f) means effective to drive said pressure rollers in a direction to guide and advance said tubular knitted fabric about said pressure rollers and through said squeezing nips while maintaining said tubular knitted 15 fabric continuously and uninterruptedly below the the predetermined constant level of said liquid level control means and therefore submerged in said dye liquid,

(g) an extracting nip located adjacent the exit end of said reservoir and above the level of said liquid level control means and comprising a pair of relatively large diameter extracting rolls having resilient outer surfaces,

(h) means mounting one of said extracting rolls at a level such that at least part, but less than all, of its surface is below the predetermined constant level of said liquid level control means and therefore submerged in said dye liquid,

(i) said one extracting roll and the last one of said pressure rollers being so mounted and disposed that transference of said tubular knitted fabric from said last pressure roller into contact with said one extracting roll is effected below the predetermined constant level of said liquid level control means and while said fabric remains continuously and uninterruptedly submerged in said dye liquid,

(j) means supporting said pressure rollers in a contacting series disposed and arranged to cause said tubular knitted fabric to travel sinuously about said rollers to expose the opposite layers of the fabric alternately to the dye bath,

(k) means comprising said pressure rollers for guiding and directing the tubular knitted fabric continuously and uninterruptedly in edge-to-edge dimension stabilizing contact with a dimensionally stable roller surface at all times while passing through said submerged squeezing nips, from at least the first to the last such submerged nip, and

(1) means supporting one of said extracting rolls in pressure contacting relation with the last pressure roller of the contacting series thereof, whereby to form an additional submerged squeezing nip constituting the last of the series thereof.

References Cited by the Examiner UNITED STATES PATENTS 238,514 3/1881 McAllister 689 786,264 4/1905 Butterworth 6822 1,893,197 1/1933 Cohn 815l 1,979,818 11/1934 Baker 68-9 X 2,045,755 6/1936 Cohn 8-151 2,239,636 4/1941 Weiss 6822 X 2,364,838 12/1944 Williams 6822 2,382,726 8/1945 Korte 6822 2,385,402 9/1945 Cohn et al. 26-55 2,441,308 5/1948 Bond 6843 X 2,445,504 7/1948 Williams 8151 2,724,254 11/1955 Zanger 6822 2,729,003 1/1956 Cohn et al. 38-52 2,849,784 9/1958 Adams 68-43 X 2,904,981 9/1959 Macomson 8-159 X 3,036,359 5/1962 Cocker 6822 X FOREIGN PATENTS 931,182 9/ 1947 France. 591,474 1/ 1934 Germany.

OTHER REFERENCES Matthews: Application of Dyestuffs, New York,

published by John Wiley and Sons, Inc., 1920 T.P. 893 M3; page 191 relied on.

IRVING BUNEVICH, Primary Examiner.

Claims

1. APPARATUS FOR CONTINUOUSLY AND UNFORMLY IMPREGNATING TUBULAR KNIT FABRIC WITH A DYE LIQUID TO PROVIDE DYED TUBULAR KNITTED FABRIC FREE OF EDGE MARKS, WHICH COMPRISES (A) A RESERVOIR FOR MAINTAINING A BATH OF THE LIQUID AT A PREDETERMINED LEVEL, (B) MEANS ADJACENT THE ENTRY END OF THE RESERVOIR FOR GUIDING THE TUBULAR FABRIC AND PRESENTING IT IN FLAT FORM INTO THE BATH, (C) A PLURALITY OF PRESSURE ROLLERS BELOW THE SURFACE OF THE BATH AND FORMING A SUCCESSION OF SUBMERGED NIPS ARRANGED SUCCESSIVELY TO RECEIVE AND APPLY CONCENTRATED PRESSURE TO THE FABRIC, (D) SAID PRESSURE ROLLERS BEING WHOLLY SUBMERGED IN SAID BATH, WHEREBY SAID FABRIC REMAINS CONTINUOUSLY AND WHOLLY SUBMERGED IN SAID BATH WHILE PASSING THROUGH SAID SUCCESSION OF SUBMERGED NIPS, (E) THE SUCCESSION OF SUBMERGED NIPS COMPRISING A PLURALITY OF NON-RESILIENT ROLLERS FORMING CONCENTRATED PRESSURE NIPS, (F) CERTAIN OF THE NON-RESILIENT ROLLERS BEING MOUNTED FOR ROTATION ON NORMALLY FIXED AXES AND BEING SPACED FROM EACH OTHER, (G) THE REMAINDER OF THE NON-RESILIENT ROLLERS BEING CONTROLLABLY AND FORCIBLY MOVABLE INTO AND OUT OF THE SPACES FORMED BETWEEN THE FIXED ROLLERS, (H) THE MOVABLE ROLLERS BEING SUSPENDED AT EACH END BY PAIRS OF SUPPORT ARMS, (I) THE SUPPORT ARMS BEING PIVOTALLY SECURED TO YOKES AT OPPOSITE ENDS OF THE ROLLERS, (J) THE YOKES BEING MOUNTED FOR PIVOTING MOVEMENT ABOUT AXES SUBSTANTIALLY CENTRALLY BETWEEN THE PIVOT AXES OF THE SUPPORT ARMS, (K) MEANS BEING PROVIDED FOR CONTROLLABLY MOVING THE PIVOT AXES OF THE YOKES TOWARD AND AWAY FROM THE NORMALLY FIXED ROLLERS, AND (1) AN EXTRACTING NIP MOUNTED ADJACENT THE EXIT END OF THE RESERVOIR AND ABOVE THE LEVEL OF THE BATH AND COMPRISING A PAIR OF EXTRACTING ROLLS HAVING RESILIENT OUTER SURFACES, (M) SAID PRESSURE ROLLERS BEING MOUNTED IN A CONTACTING SERIES, WHEREBY THE FABRIC IS CAUSED TO BE IN EDGE-TO-EDGE CONTROL CONTACT WITH A DIMENSIONALLY STABLE SURFACE WHILE PASSING THROUGH SAID SUBMERGED NIPS.