US1652649A - Dyeing process - Google Patents

Description

Dec. 13, 1927. 1,652,649 M. E. TICE 'DYEING PROCESS Filed Feb 28 1925 /Q IJ INVENTOR.

A TTORNE YS of the dye liquor thereto.

Patented Dc. 13, 1927.

UNITED STATES PATENT oFl-ucE.

MERLIN E. TICE, OF WAPPINGERS FAIS, NEW YORK, ASSIGNOR TO DUTCHESS BLEACH- -ERY, INC., OF NEW YORK, N. Y.,

A CORPORATION OF NEW YORK.

DYEING raoeass Application med February as, 192s. serieu no. 12,31s.

This invention relates to dyeing processes and particularly to dyeing with vat dyes, such as the indanthrenes and anthraqulnones and others. f

The principal object of the invention 1s to provide an economical, continuousl dyeing process of the kind described, securln better penetration and absorption of the ye 1n reduced form than attained by heretofore known processes while avoiding spottlng of the material by oxidized dye, produclng thereby an evenly dyed material 1n deep, light or intermediate tones.

The invention accordingly comprises a process for applying dyes to material which includes absorbing a reduced dye by the material, while avoiding oxidation of the dye on the material prior to absorption, and passing the material so treated into a second reduced dye bath.

In carrying out the invention in its pre-- ferred form, use is preferably made of the apparatus shown in the accompanying drawing, in which Fig. 1 is a longitudinal sectional elevatlon take-n on the line 1-1 of Fig. 2;

Fig. 2 is an end elevation looking from the left in Fig. 1, and

Fig. 3 represents a fragmentary enlarged detail view showing the first pair of nip rollers with the screen of dye liquor expressed thereby flowing down the face of the cloth.

Referring now to this drawing, 1 designates a length of piece goods of cotton, wool, silk or other material. In the preferred embodiment of the process the material'is of cotton, the various conditions for dyeing described in the preferred embodiment being particularly adapted for cotton. 2 and 3 represent nip rollers, suitably mounted at the entrance end of the apparatus. The lower roller 3 adapted to bc, supplied with reduced dye liquor from a tank 5 through a pipe 6 terminating in the bath 4 and provided with a valve 7 adapted to control the rate of flow The tank 5 is supported by piers 8 projecing from the frame 9. A valved inlet pipe 10 admits dye liquor` into the tank and a valved pipe 11 located dips -into a shallow bath 44 at the bottom of the tank may be used for drainage. A valved pipe 12 extending from the bottom of the shallow bath 4 is also provlded for drainage of this bath. The bath 4 1s substantially semi-cylindrical in form extending the length of the roller 3 and concentric therewith. A rod 13 supports a fin 14 running the length of the roller 3 and substantially parallel to its axis, risin from the bath of dye liquor on the side of t e bath at which the cloth enters. The function of the iin 14 will be later explained.

An idler roll 15 ositioned to receive cloth passing between t e nip rollers 2 and 3 is supported by the frame`9 to deliver cloth into .one end of a tank having two compartments 16 and 17 separated by a diaphragm. Compartment 16 is adapted to be supplied with a diluted reduced dye solution through a pipe 18 and is provided with a drainage pipe 19 at the bottom thereof for cleaning. Rolls 20 are positioned in the compartment 16 so that cloth traveling thereover may zigzag back and yforth in substantially horizontal paths, being preferably submerged during the entire zigzag motion. Mounted upon the diaphragm is a second set of ni rollers 21 and 22, through which the clotli emerging from the bath in compartment 16Y passes into the end of the compartment 17 adjacent the diaphragm. This compartment is provided with rollers 23 preferably so arranged that the cloth passes up and down in substantiallyV vertical lines while passing through the compartment. The rolls are so 'arranged that the cloth emerges from time to time from the liquid contained in compartment 17. The compartment is provided with an inlet pipe 24 for water preferably cold, though it may be heated, and an outlet pi e 25. Mounted uponthe opposite end of tile compartment 17 is a third set of nip rollers 26 and 27 which deliver cloth from the compartment on to a roll 28 which may be driven by means of a belt 29 operated by a pulley 30 mounted on the shaft of roller 26, driven by an outside source of power and driving roll 28 by means of a pulley 31 mounted thereon.

In carrying` out the process in its preoccupies then in the tank 5, the valve 7 1s glue.

ferred form, a solution containingthe ol- This solution is preferably made by mixing approximately'330 pounds of water with the caustic soda and adding to this the glue, the solution being brought to a boil. The remaining Water is then added and the whole is cooled to approximately 120 F. The dyestuff, with the soluble oil and pine oil, is boiled with about pounds of Water and strained into the solution of caustic soda and The hydrosulfite is then added to the mixture in powdered form and the whole is stirred until thoroughly mixed which usually about ten minutes. This mixture being opened to fill the shallow bath 4 up to 1ts proper dyeing level (see Fig. l).

The bath is replenished constantly thereafter with dye liquorfrom tank 5 through pipe`6.

One end of a length of piece goods, for example, piece goods in open width designated in the drawing by the numeral 1, 1s

started through ythe apparatus from a box.

`The cloth is then threaded in the usual manner over the enlrance edge of the bath 4, i

under the bar, 13, between the nip rollers 2 and 3, then over the roller 15. It is then zigzagged back and forth over the rolls 20. From the compartment 16 threading proceeds next between nip rollers 21 and 22, then into the compartment 17, and over the rollers 23. Through this compartment runs a stream of cooling Water preferably at about g room temperature, F. Emerging from this tank, the threading passes through nip rollers 26, 27 and then on to the roll 28.

. The compartment 16 is meanwhile filled with a re-reducing solution which is made up of the following ingredients b weight: water 1328 lbs. (approximatelyg, caustic soda 2 lbs., sodium hydrosulite 2 lbs., to which is added 27 pounds of dye liquor from the stock tank 5. Power is applied to roller 26, the cloth passed through the baths and rollers following they path indicated in threading and is dyed.

It will be noted that the liquor in bath 4,

and compartment 16 constitute reduced dye' baths, Indanthrene Blue GCD having in this instance been chosen as the dye, the alkaline hydrosulfite having been, chosen as the reducing agent, and the other materials being employed as assists.

Of course, it

will beunderstood that various other` dyes may be substituted for the dyestul finentioned and that other reducing ag'ts vand assists may likewise be employed. l

It is important to notice that the concentration of the dye bath in the' shallow bath 4 is much greater than in the compartment 16. In 4the present embodiment the con'- centration of the reduced dye fed to the bath 4 is approximately 1.2%, while that inthe com artment 16 has a concentration of .02% o reduced dye, thus the concentrated liquor is about sixty times as strong as themore dilute liquor in compartment 16. 4 llt will be further noted that the quantity ofdye vliquor 'that the bath 4 is capable oi holding at any one time is relatively smali. in ordinary practice about three gallons are contained in the bath whereas the compartment 16 contains about one hundred and sixty gallons. rlhe small capacit of the bath 4 insures rapid renewal of t e liquor therein so that the chance for oxidation of this liquor by air, with consequent spotting of the cloth by the oxidized dyestui is substantially avoided. The capacity of the bath 4 is. determined by a consideration o the variables present in the apparatus. These variables are- 1. The rate of oxidation of the given dye taken at the temperature selected, and

2. The dye absorption constant of the material which, with the rate of travel .of the material through the bath, gives the actual absorption constant or removal constant of the dye by the material.

lt we find, for instance, that at a given rate of travel the cloth"will absorb say three gallons of liquid in half a minute and then if we find upon trial that ob'ectionable oxidation-sufficient to cause iiec vs of oxidized dye to collect in `the bath-occurs in twice that time, then the capacity of the dye tank may be three gallons, since three allons will be removed from the tank by the cloth in halfa minute, which is'a shorter time than is required to oxidize that quantity of liquid. In other words, the capacity is less than that vquantity of the given reduced dye liquor which will just oxidize in the time required for the material to 'absorb the liquor from the bath 4. The How of fresh reduced dye liquor from the tank 5 is controlled by the valve 7, and is maintained at such rate that the bath 4-reniains at ractically a constant level. It will be note that some oxidation of the bath tal-:cs place duc to the liberation of'air from the cloth 1,

and occurs after the cloth meets the dye. Oxidation of the dye is thereby produced and a `foam forms containing fiecks of oxidized dye. On account of this the fin 14 is provided, which acts as a sort of dash board to prevent the foam from being carried downward and these dye lecks coming lll() preciably occur and it is not in contact with the entering cloth. Due to the pressure of rolls 2 and 3 on the cloth, a screen or curtain of expressed excess dye liquor designated as 32 in Fig. 3, continuously descends over the face of the cloth. This stream prevents the foam from touching the cloth on roll 3 while the fin 14 prevents the foam from touching the cloth entering the bath 4. It will be noted that absorption of the dye liquor takes place from the time the material passes into bath 4 and until it has been nipped by the nip rollers, 2 and 3. This absor tion occurs under the screen of liquor 32 w ich insures with the fink 14 that no oxidized dye unabsorbed by the fibre shall remain thereon.

The difference in concentration between the two reduced dye solutions accomplishes a surprising result, namely, that more dye can be caused to penetrate the fibre and hence deeper shades can be obtained, by subjecting the cloth to the highly concentrated bath and then to the dilute re-reducing bath, than is possible with two baths of equal dye strength. Furthermore under the conditions described, exhaustion of bath 16 does not apnecessary to replenish this bath with fresh dye liquor. The two baths are preferably maintained at about 120o F. and the cloth, in passing through` is preferably below the surface of the liquor to prevent oxidation. The cloth then passing into the compartment 1T? is cooled down so that unequal oxidation does not occur when the cloth is on the roll 28,

as might occur owing to varying temperature of 'the inner and outer portions of such a roll produced by unequal heat radiation, if not previously cooled.

To insure absolute uniformity of distribution `of the leuco-dye resulting from reducing the indanthrene or other dye absorbed by the fibre. the material, afterbe-ing wound np on the roll 28, may be run through a jig containing another reducing bath without dyestuff. This bath contains the following ingredients by weight: v

Lbs. Vater 200 Caustic soda 2 Hydrosulfite 2 Soap 2 This solution is maintained at 120o F. After jigging six times the solution is rcplaced by cold water and the cloth is washed twice in this water. The cloth, whether treated iii the bath without dye or not, is next treated with an oxidizing medium, such as an acid sodium bichi'omate solution containing the-following ingredients:

Lbs. Bichroiiiute, of soda 2 Acetic acid 28 Tw. strength 4 l later 300 dyestuff is per ornied, as

'the various agencies,

the reducing bath containing preferably noJ l pointed out above, to insure greater uniformity and. distribution of the leuco-dye throughout the cloth as well as to make the dye fast to a maximuni degree during washing. The subsequent treatment with acid sodium bichromate oxidizes the leuco-dye to develop the lglpeb color produced by Indanthrene Blue As pointed out above', the' invention is not limited to the particular kind of dye-bath employed but may be satisfactorily used where other dyes which are developed on the fibre are employed. For example, I have obtained highly satisfactory results employing various dyes of the Ciba class-Ciba Blue 2B, of the .Cibanone class-Cibanone Bill Blue 8G, Algol Brown R, Helindone Red B-N and Hydron Brown G. In addition, I ina y varyrthe type of reducing agent as well as that of the dye. The amount of dyestuff added to 1 60 gallons (1328 lbs.) of water in tank 5 given in the examples varies, of course, with the tone desired and with the character of the dyestuff. In employing the various dyestuffs mentioned above, I have used from 1 ounce to 3() pounds of color and the other ingredients employed have also been similarly varied. I have found in general that the ratio ofthe dye concentration in the shallow bath to that in the re-reducing bath effects good results when it is maintained within about the proportions given in the example above. Satisfactory results have also been obtained by using other relative concentrations.

he processas described is arapid and economical one. It accomplishes fixation of the dye on the fibre with relatively little oxidation or spotting ofthe cloth and the fixa tion is accomplished, as pointed out, with relatively few passages of the cloth through the dye baths to produce full shades. The cloth produced is a highly satisfactory product in appearance, feel and in fastness to such as light, milling. Soaping, washing and others.

As many apparently widely different einbodiments of this invention may be made without departing from the spirit thereof, I do not intend to limitmyself to the above specific description, except as' indicated in the appended claims.

Having thus described my invention what vlli I claim and desire to secure by Letters Patent is:

1. A rocess for applying Vat dyes to material w ich comprises absorbing a reduced vat dye by the material and assing the material so treated While the ye is in a substantially reduced state into a second reduced dye bath of very materially less concentration than the first bath.

2. A process for appl ing vat dyesto material which comprises c ipping material into a reduced vat dye bath. then under a stream of reduced dye liquor while absorption takes place, then removing excess dye liquor and then passing the material so treated While the dye is in a substantially reduced state into a second bath of reduced dye of less concentration than the first bath.

3. A process of applying vat dyes to material which comprises dipping a length of cloth into a. reduced Vat dye bath. then sul)- jecting the same to a stream of reduced dye liquor While absorption takes place, then expressing excess dye liquor from the cloth. the excess dye li uor running over a succeeding ortion of t e cloth to form the stream of dlye liquor mentioned. and then passing the cloth so treated while the dye is in a` substantially reduced state into a second bath of reduced dye liquor of less concentration than the lirst bath.

4. A process for applying vat dyes which comprises dipping the material to be dyed into a bath containing a reduced vat dye,

then passing the material so treated While the dye is in a substantially reduced state through a second reduced solution of the same dye while heated and of less concentration, and passing the material from the second bath into a bath at a reduced temperature to check oxidation of the dye.

5. A process for applying yat dyes which comprises passing the material to be dyed through a bath containing a reduced dye, thenpassing the material so treated through a second reduced' dye bath of less concentration, passing the material from the second iso bath into abath having a considerably reduced temperature. and passing the cooled material into a reducing bath containing no dye maintained at an elevated' temperature in order to insure a uniform distribution of y reduced dye upon the material.

6. A process for applying vat dyes whichv comprises absorbing a reduced vat dye by dipping material to be dyed into a hath containing the reduced dye, then while the dye is in a substantially reduced state passing the material so treated through a second re-v duced dye bath, and oxidizing the reduced dye on the material.

.7. A process for applying vat dyes which` comprises passing the material to he dyed through a. bath containing a reduced dye', then passing the material so treated through dye,

a second reduced dye bath of less concentration, passing the material from the second bath into a bath having a considerably reduced temperature, passing the cooled material into a reducing bath. containing no maintained at an elevated temperature in order to insure a uniform distribution of reduced dye upon the material, subjecting the material so treated to an oxidizing bath containing a bicliromate land then washing the material to 'rid it of 4oxidizing and other impurities.

8. A process for applying vat dyes which comprises passing the material to be dyed intoa reduced dye bath containing a dye more easily oxidized than-indigo of such limited dimensions and at such a rate that the dye liquor is removed before it has a chance to oxidize in the bath. the bath being heated to approximately 120 F., and then quickly-I cooling the material so treated by immersion in a medium at a lower temperature.

9. A process for applying vat dyes which comprises passing piece goods to be dyed into a bath, containing a dye more easily oxidized than indigo. reduced by hydrosullite, of such limited dimensions and at such a rate that the dye liquor is removed before it has a chance to oxidize in the bath, and, substantially Without oxidation of the dye on the material prior to absorption` passing the material so treated through a second bath also reduced 'by hydrosulfite and containing the same dyestufl in less concentration, cooling the material so treated, and rereducing the material so treated in a bath free from dyestuti'.

10. A process for applying vat dyes which comprises reducing an indanthrene dye with an alkaline hydrosultite. maintaining the dye bath containing these materials at approximately 120 F., passing the material to be dyed through this solution contained in a shallow bath of such dimensions and at such a rate that oxidation of the reduced indanthrene dye substantially does not occur in the bath, then passing the material so treated through a second bath containing a much smaller proportion of the same indanthrenel dye reduced by alkaline hydrosulfite and maintained at a temperature of approximately 120 F.. and then cooling the material so treated by passing through Water at approximately 70 F.. then passing the cooled material through a reducing bath conwhile absorption of the dye liquor takes place then passing the goods Whlle .the vat dye is in a substantially reduced state into a second bath of the same reduced vat dye4 but of far less concentration than the first bath, and chilling thegoods so treated to oppose oxidation of the goods on standing in the air.

12. A process for applying vat dyes which comprises dipping piece goods into a reduced vat dye\bath containing a dye more easily oxidized than indigo of such limited dimensions and at such a rate that the dye liquor is removed before it has a chance to oxidize in the bath, and' replenishing the liquor in the bath as it is removed by the piece goods.

13. A process for applyin vat dyes which comprises dipping piece goods into a reduced vat dyef bath of such limited dimensions and at such a rate that the dye liquor is re. moved before it has a chance to oxidize in the bath, replenishing the liquor in the bath rate that the dye liquor is removed before it has a chance to oxidizev in the bath, replenishng the liquor in the bath as it is removed by the plece goods, and passing the material under a stream of reduced dye liquor while absorption takes place, then removing excess dye liquor and then passing the material so treated while t e d'ye is in a substantially reduced state of such limited dimen` into a second bath of reduced dye of less 4v concentration that the rst bath.

Signed at Wappingers Falls, N. Y., Feb.

MERLIN. E. TICE. l

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