US2086298A - Dyeing of elastic fabrics - Google Patents

Description

July 6, 1937. A. lsAAc' DYEING oF ELASTIG FABRICS Filed June 5, 1955 3 Sheets-Sheet 1 IIIIIIGI llllllll Il JIZ July 6, 1937. A. lsAAc "DYEEING oF ELASTIG FABRICS 3 Sheets-Sheet 2 Filed June 5, 1935 July e, .1937. A. ISAAC 2,086,298

DYEING oF ELASTIC FABRICS i Filed June 5, 1955 3 Sheets-Sheet 5 Patented July 6, i937 acetate I nannies oir nnas'rrc nannies Augustin lisaac, lLyon, France, assigner to Dognin, Societe Anonyme, Villeurbanne, France, a company of France Application .lune 5, 1935, Serial No. 25,144

. lin France `lune l2, 193e .It is known that elastic fabrics made with made, as well in the longitudinal asin the transthreads of rubber or a similar material which is verse direction, by comparing the number of specifically elastic are very difcult to dye in an meshes when the fabric is not elongated and even manner. This dimculty is due to the inwhen itis elongated.

timate contact existing between the rubber Another feature of the invention consists in Y threads and the weft threads, which contact coupling together, through any suitable trans-v prevents the dye from fully impregnating the mission such as a chain or a pinion transmission, textiles, especially at the places where the the two cylinders of the transverse stretcher threads cross one another. Y bars in order to avoid the phenomena. of periodical 'I'he chief object of the present invention is increase and decrease of the tension during the 10 to obviate this drawback. For this purpose I dyeing operation. have provided .a process characterized in that, Another feature of the invention consists in during the dyeing operation, the fabric is not providing means, adapted to act in the course of only stretched in the direction of its width, in the dyeing process, for evening the intensity of the usual fashion, but also subjected to a subdyeing across the width of the piece of fabric, 15 stantial elongation, either in the longitudinal or l in such manner that the shade should not be in the transverse direction, or eventually in both deeper along the edges than in the central part of these directions. In this manner, the volurne of the piece. For this purpose I may provide of the rubberthreads, when they are elongated,` means f01` Performing a supplementary Sprindecreases so that these threads cease to be in klingof the central partv of the piece of fabric 20 intimate contact with the other threads of the that is to say of the part o f said piece extending fabric. Therefore said fabric can be fully imfrom the median line thereof to a certain dispregnated by the dye in which it is immersed. tance from the edges. I may also, according to' Other features of the invention relate to the the invention, provide the rollers on which the application of the process above mentioned by fabric is wound up with suitable cheeks or side 25 means of dyeing apparatus of the Well known plates Which Prevent direct lateral Contact bejigger type. The elongation of -the fabric is tween the mass of fabric wound up on the roller obtained by exerting on the roll of fabric that'is and the surrounding space. I'lnay e180, Still ee'- being unwound a strong braking action sumcording to the invention, provide means for excient in order that, through elastic deformaertingacomplementary compression on the mar- 30 tion, the portion of the fabric that passes ginal edge 0f the fabric, these Ineens including, through the dyeing vat may be elongated to an for instance, two smalllateral compressing memamount ranging between 15% and 100% and bers, mounted on the transverse stretcher bars even more. or on the outlet end transverse stretcher bar,

Furthermore, the rollers on which the fabric these members being arranged to compress the 35 is wound up and from which it is unwound are marginal DOlliOnS 0f the T011 0f fabricprovided with brake drums having free wheel de- Still another feature of the present invention vices acting in opposite directions, so that each consists in controlling the winding up of the of the rollers, which acts alternately for windfabric on the corresponding roller in such moning up the fabric and for unwinding it, can be ner that its Width may remain uniform. For 40 braked when it is acting -for unwinding the this purpose, the action of the transverse fabric, while the other roller is not brakes and stretcher bars is regulated in a suitablemarmer, is imperatively caused to rotate, this result beby varying, for instance manually, the angular ing obtained without removing the braking position of the transverse stretcher bar or of a weights. portion of said bar. 45

Finally, the curved guiding, or transverse Other features of the present invention will stretcher, bar may be provided with a miororesult from the following detailed description of metric device for adjusting its angular position in some specific embodiments thereof. Y such manner as to permit of adjusting the Preferred embodiments of the present invention stretching in the transverse direction. Furtherwill be hereinafter described; with reference t0 50 more, bars provided with clips may eventually the accompanying drawings, given merely by way be utilized when the elongation in the transof example, and in which:

verse direction is to be very important, for in- Fig. 1 is a diagrammatic vertical sectional view stance greater than 30%. of a jigger apparatus modified according to the The measurement of the elongation can be presentinvention; 5

Fig. 2 is a diagrammatic plan view corresponding to Fig. 1;

Figs. 3 and 4 are detail views illustrating the arrangement of the free wheel devices mounted on the rollers on which the fabric is wound up and unwound Fig. 5 is a sectional view on the line 5 5 of Fig. 4;

Fig. 6 is a detail view, on an enlarged scale, of aportion of the apparatus of Fig. 1, showing the curved transversestretcher bar;

Fig. '7 is a plan view corresponding to Fig. 6;

Fig. 8 is a diagrammatic detail view showing the shape of the transverse stretcher bar;

Fig. 9 is a vertical sectional view of another embodiment of the apparatus of Fig. 1;

Fig. 10 is a perspective view showing a device for compressing the marginalportion of the roll of fabric;

Fig. 1-1 is a vertical transverse section of the device of Fig, 10;

Fig. 12 is a side elevational View of a device permitting of regulating manually the angular position of the transverse stretcher bar;

Fig. 13 is a plan view corresponding to Fig. 12;

Fig. 14 shows a modification corresponding to the case of a transverse stretcher bar made of two halves adjustable with respect to each other.

In the embodiment shown in Figs. 1 and 2, the jigger apparatus includes a vat a containing the dyeing bath and in which passes the fabric b which is unwound from a roller d and wound upon a roller c. Each of these rollers serves, alternately to the winding up of the fabric and then to the unwinding thereof. T'hese rollers are driven through a transmission shaft m which can be coupled,through a clutch p, with either of two bevel pinions An and o, as shown by Fig. 2.

On the vat or tank is mounted the oscillating frame e at the ends of which the transverse stretcher bars f1 f2 and the guiding rollers g1 g2 are mounted. The rollers c and d which serve alternately to the Winding up and the unwinding of the fabric are keyed on shafts c1, d1, respectively. These shafts are adapted to Ibe braked through drums c2, d2 subjected to the action of braking bands h, i carrying weights k, l, respectively, or in any other suitable manner.

A pawl and ratchet device c3, d3, or any other equivalent device acting as a. free wheel, is interposed between each of the shafts c1, d1 and the corresponding brake drum c2, d2, but the teeth of these respective ratchet devices are disposed in opposite directions, that is to say the free-wheel devices act in opposite directions.

Under these conditions, the two braking devices h k and 1l Z being constantly in action, the free wheel devices produce a strong braking of roller d, from which the fabric is being unwound, while leaving the roller c on which the fabric is being Wound up free to rotate, whereby this last mentioned roller can be driven by transmission shaft m and exerts a pull on fabric b. This pull, acting against the braking action of brake i I, produces an elongation ofthe fabric in the longitudinal direction, by elastically deforming the threads of said fabric. Only when the elongation has reached a certain amount (which depends upon the importance of the braking action) does the fabric b move for winding up upon roller c while unwinding from roller d. V'Iherefore the fabric passes through tank a not only stretched transversely so as to be fiat, as in the case of ordinary fabrics made of non-elastic threadsrbutin a state ci' elongation, this elongation being eventually efforts may be as high as 1000 kilograms andeven more.

When the whole of the fabric is wound up on a roller c, it is unwound froml said roller so that the fabric moves in the opposite direction, the free wheel devices automatically transferring the braking action from one roller to the other one.

While the fabric is moving in the bath it is not only elongated but also fully stretched in the transverse direction owing to bars .f1 f2. According to the present invention, it is possible to adjust the inclination of each of these bars in such manner as to bring it .out of the way or, on the contrary, to give it -a suitable angular position. The adjustment preferably takes place through a micrometric control, as shown in Figs. 6 and '1, by means of a screw q acting on a wheel r keyed on the spindle f about which bar f1 or f2 is pivoted.

It should be noted that when the bar is in the position shown in Fig. 6 or close to this position,

it produces, because of the tension imparted to the fabric b, a stretching of said fabric in the transverse direction, whereby the dye is allowed to penetrate fully into the -fabric.

The transverse stretching bar can be replaced, once the correct adjustment has been found, by a non-cylindrical roller of analogous profile, as shown in f3 in Fig. 8.

It is desirable, in order to dye the fabric as evenly as possible, to work with an elongation as uniform as possible. But a diiiiculty arises: The

`diameters of the rollers on which the fabric is wound up and from which it is unwound simultaneously increase and decrease, respectively, thus varying the resulting braking action and elongation. This diiliculty was not experienced in the jigger apparatus as used up to this time, because it was only desired to cause the fabric to pass through the bath in a regular manner, without folds. As a matter of fact, for most fabrics, special devices were used for reducing the tension of the fabric to a minimum and apparatus were devised in which this tension was practically eliminated. On the contrary, according to the present invention, it may be desired'to render the braking torque as uniform as possible, automatically if possible, for instance by making use of a band brake which is tensioned not by a free weight but by means of a lever along which said Weight can slide. The automatic displacement of this weight along said lever can be obtained through a roller which bears constantly upon one of the rolls of fabric and the displacements of which control the displacement of the weight along the lever.

In order to reduce to a minimum the necessity of this adjustment, and even to eliminate it in some special cases, another modification to the ordinary jigger apparatus shall consist in increasing the diameters of the rolls of fabric as much as possible, for instance by making them twice or even thrice greater than the usual values. In this way, the relative difference of tension due to the variation in the diameters of the rolls will be considerably reduced, especially when the apparatus is utilized with pieces of fabric of relatively short length.

It should be well understood that, by suitably adjusting the apparatus, it is possible to utilize, according as the need may be, either combined elongation and transverse stretching or only elongation.

By `comparing the dyed fabrics obtained ac- .esv

cording to the ordinary methods and those cbabscess tained in accordance with the present invention by means of a jigger or any other apparatus permitting to subject the fabric to a suitable elongation,A the following is noted:

(a) the dyeing action is uniform owing to the elimination of the differences resulting from the non-uniform tensions of the weft on the warp;

(b) the breaks that occur generally when dyeing heavy fabrics are eliminated;

(c) the dye penetrates in a perfect manner into the fabric;

(d) the fabric is not injured and is not displaced;

(e) the fabric is more regular and even due to the combined action of elongation and transversev stretching of the fabric while passing through the dye bath at high temperature. This result is explained by the reduction of the tensions of the rubber threads under the influence of heat and the resetting in position of the vegetable or animal textile fibers under the influence of elongation and transverse stretching.

This last action makes it possible to obtain fabrics which are perfectly fiat and smooth in spite of irregularities of the raw material, while when no elongation is produced the finished fabric has a very unfavorable corrugated aspect.

The rollers that are utilized in actual practice receive pieces of fabric of considerable length and weight and they mustbe subjected to important braking efforts. Consequently they must be very strong and consist of solid drums having a considerable inertia. When they are charged with pieces of fabric they are capable of storing up an important amount of energy. Taking into account the elasticity of the fabric, it will be easily understood that the following phenomenon can occur: When the driven roller is brought into action, the fabric extending between the two rollers'is tensioned more 'than it would do if the working speed were obtained because the fabric must overcome not only the resistance opposed by the brake but also the inertia of the roller that is being braked. When said roller has reached a certain speed of revolution, the tensionv tends to decrease but it does not take the value v it should have because the roller that is braked,

which has been started under the influence of a high tension of the fabric now feeds fabric at too high a rate. The tension of the' fabric now drops down to an exaggeratedly low value, the speed of revolution of the braked roller decreases and the same phenomena again occur and may become periodical.

The present invention includes improvements to the machine above described for obviating the detrimental action of the inertia of the rollers on the uniformity of tension of the fabric and therefore on the quality of the product.

One of these improvements consists in reducing the diameter of the rollers the mass of which is, in fact, concentrated chiey in the vicinity of the rim.

Another improvement, which may be -employed either separately or in combination with the above mentioned one consists in coupling with the roller from which fabric is being unwound a governor of any kind modifying the braking of the roller in accordance with the speed of revolution of said roller so as to render thisspeed as uniform as possible.

Alternately, and eventually in combination with the first of the two above mentioned improvements. the two rollers may be interconnected, since one roller must receive as much fabric as there is fabric unwound from the other one.

bcdiment illustrated by this figure, the pinions or sprocket wheels t1, t2 keyed on the spindles of rollers g1, gz are connected together by means of a chain u.

The angle made by the fabric b when passing around these rollers g1, g2 is relatively small but.

still it is sumcient for giving said rollers, although their surfaces are smooth, an adhesion with the fabric sufficient for reducing the detrimental action of the periodicity above mentioned and'even eliminating this action, whereby the fabric is unwound in a continuous manner at a uniform rate.

A. particularly interesting advantage of the interconnection of the rollers of the transverse stretcher bars by means of a chain or the equivalent is to eliminate the undesirable polishing of the pieces of elastic fabric. As a matter of fact, up t'o this time, the periodic variations in the unwinding of the fabric above referred to produced not only unevenness of the dyeing and, even in some cases, sliding displacements of the weft, but also friction between the successive layers wound up around the cylinder. This friction produces on the surface of the fabric traces similar to snail tracks. Similar traces are also produced when the bad working of the roller produces at a certain'time the stoppage of a transverse stretcher bar roller. These traces result in this case from friction of the fabric on the stopped roller.

These drawbacks are fully obviated when the rollers are interconnected.

A well known drawback of dyeing with the jigger apparatus is the edge effect which consists in the fact that the edges of the fabric are dyed to a deeper shade than the remainder of said fabric.

The special texture of elastic tulle or similar fabrics, which are more permeable to liquidsthan ordinary fabrics, accentuates this drawback. It is therefore necessary, when dyeing elastic fabrics such as tulle or net, to correct this defect as fully as possible.

For this purpose, I may, without trying to eliminate the causes that produce this deeper dyeing along the edges, compensate for this effect by reinforcing the intensity of dyeing of the central part of the fabric. This result is obtained by soaking this central part alone with the dye bath itself, which is pumped up from the bottom of the tank through filtering screens.- The liquid is fed through valves provided in sufficient number to nozzles distributed along the axis of the apparatusand above every roller. A

I may also, according to the present invention, try to eliminate the cause of the phenomenon by fitting to the roller, on either side of the roll of fabric wound therein. adjustable cheeks which transform. the roller into a kind of huge spool and prevent'lateral contact of the roll of fabric with the surrounding'bath and consequently any abnormal circulation of liquid through the fabric by capillarity.

I may also, according to the presentinvention, provide means for exerting on the marginal portion oi' the roll of fabric a compression intended to drive out the liquid that has a tendency to accumulate. in said portion of the roll of fabric. Preferably, these means must be so devised as to produce a compression as uniform as possible of the edge of the roll of fabric and of a marginal portion thereof extending to some centimeters from said edge.

Figs. 10 and 11 show an embodiment in which the compression of the edge and marginal portion of a roll of fabric b1 is obtainedA through a band offrubberized fabric o1 suitably tensioned by means ofl weights q1. v

I may also apply upon this edge and marginal portion of the roll of fabric a wide surface .and cause it to compress the fabric as uniformly as possible for instance by means of' levers loaded` with weights at their end'and working in juxtaposition. In either case it is necessary to obtain an action of the weights the component of which toward the center of the mass is relatively important.

I may still adjoin to each transverse stretcher bar roller and on either side thereof a small compressing cylinder, applied thereon through any suitable means. These two lateral cylinders shall compress the marginal portions of the fabric over a distance sufficient for obtaining the desired result.

The edge effect above described is complicated, in the case of fabrics that are extensible in the transverse direction, by the fact that the edges are not evenly dyed. 'I'his defect is due to the fact that, during the winding of the fabric, its width does not remain uniform. 'I'his defect may, in somecases, be still more important than the edge effect proper. In order to obviate this drawback, the action of the transverse stretcher bars f1, f2 is controlled through means permitting tol vary it instantaneously by modifying the angular position of said bars.

For this purpose, as shown in Figs. 12 and 13, the' end of each bar, such as f1, is provided with a lever s1 provided with means s2 for fixing it in any desired angular position about the axis of f1. It will be readily understood that, by displacing this lever the inclination of the bar and therefore the action thereof can be modified at will.

In the embodiment shown by Fig. 14, the bar is made of two halves, such .as f, adapted to turn independently about a central support v. To the end of each portion i of the bar there is xed a lever so arranged in the'same manner as lever s1 so as to permit of varying the inclination of each portion of the bar and of obtaining a perfect adjustment of the action on the respective edges of the fabric. This arrangement also permits of remedying the tendency of the fabric to move as a whole toward the right hand side .or the left hand side.

While I have, in the labove description, disclosed what I deem to be practical and eiiicient embodiments of the present invention, it should of the present invention as comprehended within the scope ofthe appended claims.

What I claim is:

1. A methodof dyeing elastic fabrics which comprises stretching the fabric by an amount at least equal to 15 per cent while passing it through the dye bath.

2. A method of dyeing elastic fabrics, which comprises elongating the fabric in the longitudinal direction while passing it through a dyeing bath, the amount of elongation being at least equal, to 15 r cent. 3. A me od of dyeing elastic fabrics, which comprises elongating the fabric in the transverse direction, while passing it through a dyelngbath, the amount of elongation being at least equal to 15 per cent.

4. A method of dyeing elastic fabrics, which comprises elongating the vfabric both in the longitudinal direction and in the transverse direction, while passing it through a dyeing bath, the amount of elongation in each of said directions being at least equal to 15 per lcent.

5, A method of dyeing elastic fabrics having rubber threads disposed therein, which method comprises elongating said fabric in the direction of said rubber threads by4 an amount at least equal to 15 per cent, while simultaneously passing said fabric in operative contact with dyeing material.-

6. A method of dyeing elastic fabrics includ ing a set of rubber threads disposed in contacting relation with a set of other threads, one of the sets being at least a part ci' the weft while the other set is yat least a part of the warp of said fabric, which method comprises stretching said fabric in the direction of the rubber threads for elongating the latter to such an extent that the cross-section of said rubber threads issubstantially reduced, thus reducing the contact between 'the sets of threads, while simultaneously passing said fabric in operative contact with dyeing material.-

7. A method of dyeing elastic fabrics including a set of rubber threads. and at least one furtherl set of threads which individually form tight loops about said rubber threads so as to be in close contact therewith, which methodcomprises stretching said fabric in the direction of the rubber threads for elongating the latter, to such an extent as to relieve the loops from contact with said rubber threads, while simultaneously passing said fabric in operative contact with dyeing material.

v8. A continuous method of dyeing lengths of elastic fabric having longitudinally disposed rubber threads, which comprises feeding said length into andpast an inlet nip then into and past a remote outlet nip, elongating said length between said inlet nip and said outlet nip by an amount at least equal to 15 per cent, while simultaneously passing said length between the nips in operative contact with dyeing material, and

positively synchronizing the rates of feed through said inlet nip and `outlet nip respectively.

9. The method of claim 8, further comprising spreading said length of fabric in the transverse direction while passing the 'same in operative contact with the dyeing material.

AUGUSTIN ISAAC.

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