MXPA99004813A - Method and device for continuous dyeing of warp ends - Google Patents

Abstract

The invention relates to a method for the continuous dyeing of warp ends, in particular cotton warp ends, with indigo or other dyestuff groups which, after impregnating and squeezing out, require oxidation or thermal treatment for fixing. The method eliminates the disadvantages of traditional methods for the continuous dyeing of warp ends. In particular, the required bath amount is considerably reduced by this method. By using a new dyeing reactor (1), the residence time of the warp ends in the dyeing installation can be varied without having to increase the bath volume. The option of heating or cooling the dyeing bath enables a fixing temperature between below room temperature and over 100°C to be chosen. Optimal conditions can thus be created for all dyeing methods which are habitual for warp ends. In this way, the number of immersion-oxidation processes in the indigo dyehouse can be reduced and the growing demand for indigo blue jeans material with different wash resistances and shades can thus be catered for with increased flexibility. And the same can be done for black and coloured denim.

Description

PROCEDURE FOR CONTINUOUS DYEING OF URDIMBER THREADS, AND DEVICE FOR CARRYING OUT THE PROCEDURE The invention relates to a process for the continuous dyeing of warp yarns, in particular cotton warp yarns with indigo or another group of dyes, which require oxidation or a heat treatment after impregnation and squeezing, to develop the color and fix it.

Machines are known for dyeing warp yarns for indigo dyeing for Denim blue, which are composed of colorant containers placed one after another, with a squeezing device, or color feeders with relatively large bath volumes. These colorant containers or feeders are also used for dyeing with sulfur dyes or vat dyes for black or colored denim. To solve problems of color runoff and to achieve a better performance of the dye, it is known that an additional machine unit is integrated for warp yarn dyeing, which is composed of a color spout with reducing gutter, followed by a vaporizer , this unit can not be applied in the main production of indigo dyeing.

The known dye containers with squeezing device, or the color feeders are composed of simple roller sliders, by means of which the warp to be dyed is impregnated, driven, deflected and then squeezed through one or more cylinders or odillos and / or deflection rollers. The trajectory of the warp through the bath, and thereby the residence time in the dyebath is determined by the amount of the cylinders in the bath and the deflection rollers and the distance from one to the other.

Since the warp speed in indigo dyeing is predetermined and practically unchanged, the immersion time and the bath volume are constant, and thus only depend on the construction of the dye container.

Due to the growing demand for jeans fabrics in indigo blue with different wash fastness and different nuances, it is required, for indica dyeing from light blue to strong blue, as well as "for the marked portions of the black denim and color, great flexibility.

For example, different shades require for light shades in conventional indigo dyeing facilities, the use of fewer colorant containers. For darker shades, more colorant containers placed one after the other are required. For a dark shade, in most cases six colorant containers are used, with respectively up to 2 500 1 of dye bath. This means that "conventional indigo dyeing facilities must be adapted for the production of different shades.According to the desired shade, colorant containers must be removed or added, and at the same time pumping or extracting dye baths. dye that is not used at the moment, which can be several thousand liters, must be temporarily purged or stored.

In the known cyclic dye installation (Loopdye), only a dye bath is needed, through which the warp yarn mall is conducted several consecutive times, in the case of dark indigo shades four or five times.

Other shades, such as indigo blue, are stained with another group of dyes, mostly sulfur dyes or vat dyes. These groups of dyes, and also the common groups of dyes "for cotton, such as reactive and direct dyes, have different affinities to cotton, in most cases affinity higher than indigo." Affinities are greatly influenced Because of the temperature of the dye, which can be very different between different groups of dyes, in this way, for example, the affinity and the yield of the indigo increases when the temperature decreases, while it also increases with other groups of dyes, when the temperature.

With the cooling of indigo dye baths a high affinity and dye yield could be achieved in the current machines, but due to the large number of dye containers and the large amount of the dye bath, this is not economical.

An additional problem, which occurs in the current dyeing machines, is that by affinity, dye is extracted from the bath.

This leads to the beginning of the game being dyed darker than the end of the warp thread mesh, and that the so-called head-tail cycle also develops. This developed feature, which can be displayed over several thousand meters of the warp to be dyed, is related, especially for large installations, with large bath volumes, which lead to large dye runoff.

Therefore, it is an object of the invention to eliminate the disadvantages of known methods for continuous dyeing of warp yarns, in particular cotton warp yarns with indigo or other groups of dyes, which need after impregnation and squeezing , to be fixed, an oxidation or a heat treatment. In particular, the necessary quantities of bath should be reduced significantly, and should allow economic requirements for a cooling or heating of the dye bath. This also makes it possible to adjust the residence time of the warp wire mesh in the dyeing installation with simple tools, and the fixing temperature must be able to be chosen from a temperature below room temperature to 100 ° C.

It is the task of the invention to achieve a process for continuous dyeing of warp yarns, especially cotton warp yarns, with indigo or another group of dyes, which makes possible a high variability in the dyeing of warp yarns with different shades , but also with different groups of dyes, as well as a device that tina under the respective optimal conditions when using indigo dye, sulfur dye or vat.

According to the invention, this task is solved because a warp wire mesh is conducted through a closed dyeing reactor sealed in the air, which adapts itself to the optimal technological conditions of the respective group of dyes. For this, the warp yarn mesh is impregnated in a fresh dye bath, after an initial dip, and at the end is squeezed in an intermediate squeezing facility that is in the reactor. The permanent fixation is then carried out by means of conductive or deflecting rollers, under the elimination of oxygen, either without, or if desired, with repeated immersion in a fresh dye bath, whereby the residence time of the The warp yarns in the dyeing reactor can be adjusted variably, according to the desired shade of color and the technological conditions of the respective dye group.

The dyeing reactor according to the invention is a container closed at the top, having in the lower part openings for the entry and exit of the warp wire mesh. Underneath the dyeing reactor, containers are placed for the dye baths into which the lower opening of the reactor is immersed. These containers form at the same time a water regulating chamber with conduction and deflection rollers, which seal the dyeing reactor to the environment, and through which the warp yarn mesh is guided inwards and outwards. In addition, in the entrance gutter can be placed another squeezing facility, which removes the air that still contains the warp threads that will enter. These containers are equipped with a double bottom, by means of which the indigo dye bath is cooled, although other dye baths, for example sulfur dyes, can be heated. In the dyeing reactor, an intermediate squeezing system is placed, whose squeezing pressure can be varied until there is no pressure. In place of the intermediate squeezing facility, or together with it, roller pairs can be placed, which collect the dye bath which runs off when the squeezing device is open, thus avoiding the dripping of the dye bath. The pairs of rollers are adjustable and are positioned in such a way that the warp yarn mesh must express an S curve or an approximately Z curve. By means of the driving and deflection rollers placed in the inner space so that they move vertically, the residence time of the warp yarn mesh can be shortened or lengthened according to the technological requirements.

At the bottom of the dyeing reactor is placed a hydraulic pipe system to feed the reactor with dye baths, this circulation system consists of supply pipes with pumps as well as several valves and serves for the circulation of the bath of dyeing and impregnation, and in special cases, for the dosage of a more concentrated raw material.

In the following description of examples of embodiment based on the annexed drawings, additional modalities, characteristics to details and advantages according to the invention procedure as well as to the device for its realization according to the invention are presented.

They show: Fig. 1 a section dyeing reactor a side view, Fig. 2 shows the reactor according to Fig. 1 with a warp yarn path cut out, Fig. 3 the dyeing reactor of Fig. 1 in the dyeing with the smallest bathing amount, Fig. 4 the dyeing reactor of Fig. 1 in the dyeing with the largest bathing amount.

The dyeing reactor 1 shown in FIG. 1, by way of example, is a container closed at the top. On its lower side it has three dye containers 2a, 2b and 2c, which are filled with colored baths. The containers 2a and 2c are at the same time water regulators, that is to say, the lower part of the side walls of the dyeing reactor 1 are raised until they touch the containers 2a and 2c with coloring solution, so as to prevent the entry of air environment, especially oxygen from the air, to the dyeing reactor 1. In addition, an additional squeezing device 3c can be placed in the inlet tub 2a, which removes the air still contained in the incoming warp wire mesh. In addition, the containers 2a and 2c contain double bottoms 7a and 7b, with which the coloring solutions (in the case of indigo) can be cooled or heated (for example for sulfur dyes).

In the dyeing reactor 1 there is an intermediate squeezing device 3a, which can squeeze the warp yarn in such a way that "dyeing faults" do not occur during the advancement of the warp yarns. With this intermediate squeezing device 3a, the squeezing pressure on the warp yarn mesh can be varied by means of pressure rollers to a zero pressure value.

In place of the intermediate squeezing facility 3a, or in addition to it, pairs of rollers Al, A2 can be placed, which collect the coloring solution when the squeezing system is open, and thereby prevent dripping of the coloring solutions. The pairs of rollers Al, A2 are adjustable, and are placed in such a way that the warp yarn mesh must make a S curve or a Z curve.

In the dyeing reactor 1, driving and deflection rollers 4a, 4b, 4c are located immediately above the containers 2a and 2c. These are the so-called rollers under the water regulator bath. The conveying of the warp wire mesh through the dyeing reactor 1 takes place by means of additional guide and deflection rollers 5a to 5g. These guide and deflection rollers 5a to 5g are called rib rollers. The ribs 11 of these rollers avoid the eventual crossing of the yarns. The rib rollers remain free of dirt and fibers, thus preventing the thread from breaking. In addition, these guide and deflection rollers 5a, 5b, 5c and 5g are vertically adjustable in the reactor, whereby the length of the warp yarns can be varied. In the example according to fig. 1 The feeding length Kl is 16m. In the example of fig. X shows the cut feed K2, which is 7m.

The cover of the reactor 8 can be heated and placed in transverse fall, thereby avoiding dripping. In addition, the dyeing reactor 1 can be heated by a circular tube 9 with steam.

In case of hot fixation with steam, for example, with sulfur dyes, surplus steam is removed by means of a chimney 10. The chimney 10 has an overpressure regulator, ie it is opened with a vapor pressure determined.

In Fig. 3 and 4, the hydraulic pipe system and the reactor feed are represented with dye solutions.

The dye feed is carried out by means of an inlet lia. The uniformity of the inlet solution, which is of higher concentration of the impregnation solution, is ensured because * this flows on a horizontal dam over the entire width of the reactor in the first container of dye 2a. The volume of the coloring solution in this first container 2a can be for example 150 1.

The flow of the coloring solution can be carried out either by means of an overflow llb or an overflow 11c, depending on which dye containers contain coloring solution. Also here the uniformity of the flow to - through the entire width of the reactor it is secured by means of horizontal dams.

The overrun of the squeeze and the spent dye solution of a main squeezing device 3b which is located on the outside of the dyeing reactor 1 is carried out through a lid outlet.

The circulation of the coloring or impregnation solution which is very important for a uniform dyeing is guaranteed, in case the small bath volume of 150 1 is chosen, by means of a circulation pipe system 12a and 12b with a pump of circulation 14, which has a variable expense between 600 and 6000 1 / h. In case the impregnation is chosen in the two containers 2a and 2b, with a volume of coloring solution of 150 1 in the first container and 80 1 in the second container, the circulation of the solution is carried out by means of a second circulation system 12a and 12c, in the same way by means of the circulation pump 14.

The choice of the small or larger circuit of the coloring solution is controlled by means of the valves 13a, 13b and 13c. The valve 13f in the drain tube prevents the accumulation of solution in the case of choosing an empty container.

The feed of the spent coloring solution from the main squeezing plant 3b to the dyeing reactor 1 is carried out by means of an additional circulation system 12d and can be regulated by means of a valve 13d.

The concentration of the coloring solution required continuously, with the respective amounts of dye and chemicals, which is exhausted by the dyeing of the warp threads that enter, is carried out by dosing a more concentrated feed through an inlet 16 with a dosing pump 17, which can be regulated by means of the valve 13e. This mixture of the additional feed to the two coloring solutions that are in circulation, of the circulation solution and of the spent solution of the main squeezing unit 3b, is carried out by means of a mixing container 15 with a volume of • 30 1 solution, including the pipes.

With this the total volume of coloring solution distributed in the dyeing process will be, in a preferred example, and using only the first colorant container 2a: 150 + 60 + 30 = 240 1 In the case of the feeding of the two colorant containers 2a and 2b, the total volume is: 150 + 80 60 -t- 30 = 320 1 Naturally, other total volumes of coloring solution to be used are also possible. In this way, for example, a decrease can be made using displacement bodies in the colorant containers, and an increase increasing the inflows and outflows and increasing the level of solution.

Next - two preferred dyeing processes will be described by means of exemplary embodiments.

Example 1: In a dyeing with indigo in a standard naval blue shade, a coloring solution with a total volume of 320 is used 1. An indigo immersion bath is placed with 3g / l of indigo and the necessary amount of sodium hydroxide and acid sulfite as reducing agents, to reduce the dye.

After filling the colorant containers 2a and 2b and container 2c of the main squeezing facility 3b, the "last" in a 1: 1 dilution, the coloring solution is put into circulation by means of the circulation system 12c, 12a and the_bomb _14._ The position of the valves is as follows: the valves 13a, 13c, 13d and 13e are open, the valve 13b is closed.

The dyeing speed can be up to 50 m / min due to the long length of the threads (16 m).

The impregnation solution is cooled to 15 ° C for the purposes of this example, thereby substantially increasing the affinity of indigo to the cotton yarns. This also prevents temperature changes that affect the environment from inside the reactor.

The feeding of the prepared additional substance of 80 g / 1 of indigo with the necessary chemicals is carried out proportionally to the weight of the warp threads that are going on. The control of the dosage is performed by a PC, which measures the length of the warp yarns, transforms it to weight per unit time (18 kg / min), and then proportionally doses the additional substance. In this example 4.5 l / min of additional substance solution is dosed for a 2% dyeing at an additional substance concentration of 80 g / l.

When the length greater than 16 m is chosen, the dye performance will be the maximum possible, the same for the resistance to. washed.

When a smaller length is chosen, the resistance to washing will not decrease to a great extent, more than what could be required of a STONE washer. Example 2: é In the dyeing with sulfur dye for black or colored denim, the same procedure as described in Example 1 is described, with the exception that in this process only the first dye container 2a is used and thus the volume total is reduced to 150 + 60 +30 = 240 1.

In addition, the coloring solution is heated to at least 90 ° C and the interior of the reactor at 100 102 ° C by means of steam.

The length of the warp yarns will be 16 m for this purpose, since a long residence time guarantees the best dyeing performance.

Claims (21)

1. Procedure for continuous dyeing of warp yarns, especially yarns of. cotton warp, with indigo or with other groups of dye, especially sulfur dyes and vat dyes, in which a mesh of non-woven warp yarns is impregnated which is conducted parallel by means of which it is conducted through a reactor of closed dyeing sealed against air which comprises one or more colored containers filled with a coloring solution through roller or colored branch sliders, as well as through several cylinders or rollers and / or deflection rollers, which are in the dye bath to lengthen the residence time; then "squeezed into a squeezing device, washed, softened and then rolled into a warp folder, characterized in that the warp thread mesh is conducted in such a way that it is impregnated in fresh dye solution after a initial immersion, is then squeezed in an intermediate squeezing facility located in the dyeing reactor and then the permanent fixation is made in the absence of oxygen through driving and deflection rollers without repeated immersion in fresh coloring solution, with the that the residence time of the warp yarns in the dyeing reactor can be varied, according to the desired color tones and the technological requirements of the respective dye groups.

2. Process according to claim 1, characterized in that, the warp thread mesh is immersed after entering the dyeing reactor, in a bath of indigo dye with a solution content of less than 300 1 and with a concentration of 3 g / 1, after the squeezing in the intermediate squeezing plant, the concentration in the warp is reduced by about half, so that in the subsequent residence time of the warp wire mesh in the reactor, the concentration Still high of 3 g / 1 can be transferred to cotton threads.

3. Process according to claim 1, characterized in that, in the dyeing with indigo, the cooling of the coloring solution and the permanence of the warp yarn mesh in the dyeing reactor can be adjusted in such a way that an maximum coloring performance and that the amount of colorant containers, that is, the immersion-oxidation processes to be repeated, are minimized.

4. Process according to claim 1, characterized in that, to save dye, the concentration in the bath of the inlet container is adjusted so small, that after the squeeze is on the warp very little unfixed dye to be washed in the next wash bath.

5. Process according to claim 1, characterized in that an inert gas, for example nitrogen, is introduced to prevent oxidation of the dye in the hermetically sealed dyeing reactor.

6. Process according to claim 1, characterized in that, in order to avoid the oxidation of the dye in the hermetically sealed dyeing reactor, the air found in the mesh of warp threads that enters is extracted under the solution by means of an installation of squeezing placed at the entrance of the dyeing reactor. -7.

Process according to claim 1, characterized in that, the solutions of indigo dye found in the colorant containers, can be cooled to increase the affinity.

Method according to claim 1, characterized in that the sulfur or vat dyes which are in the colorant containers can be heated, and in which the interior space of the reactor can be heated by means of steam .

9. Process according to claim 1, characterized in that, the squeezing of the warp yarns in the intermediate squeezing device can be adjusted or varied to influence the continuous dyeing and the washing resistance.

10. Procedure according to claim 1, characterized in that, the uniformity of the feeding of the dye solution to the dyeing reactor, which resides in the concentration of the impregnation solution, is guaranteed at the inlet with a dam, while the dye solution outlet can be made by means of one of the two exit dams, according to the choice of one or another dye containers, which contain the impregnation solution, and the overflow of the extruded and the spent dye solution is carried out through the installation of the main squeeze that is outside the dyeing reactor, and of the dam.

11. Process according to claims 1 and 10, characterized in that the circulation of the dye impregnation solution through a circulating system with a circulation pump is carried out by determining the choice of a low or large volume of solution. by means of a valve, and the feed of spent coloring solution of the main squeezing system is made through the pipe system With an adjustable valve.

Method according to claims 1, 10 and 11, characterized in that, the concentration of the coloring solution necessary continuously, with the amounts of colorant and respective chemicals, which is exhausted by the dyeing of the warp threads that enter, it is carried out by dosing a highly concentrated feed through an inlet with a dosing pump, which can be regulated by means of a valve.

13. Device for carrying out the method according to claims 1 and 12, characterized in that, at the lower end of the dyeing reactor, several containers are placed for the coloring solution, which form the bottom of the reactor, whereby the containers that protruding from the side walls form at the same time a water regulating chamber with conduction and deflection rollers, which serve as environmental sealings for the entrance and exit of the warp yarn mesh; and in that in the dyeing reactor are placed an intermediate squeezing system, whose pressure can be adjusted to zero pressure, as well as conduction and deflection rollers, also below the dyeing reactor there is also a hydraulic pipe system to feed the reactor with coloring solution.

14. Device according to claim 13, characterized in that the guide and deflection rollers are placed vertically displaceable in the dyeing reactor to lengthen or shorten the warp yarn mesh.

15. Device according to claim 13, characterized in that the driving and deflection rollers are formed as rib rolls.

16. Device according to claim 13, characterized in that pairs of adjustable rollers, preferably Teflon rods, are placed in the dyeing reactor in order to separate excess coloring solution.

17. Device according to claim 13, characterized in that the bottoms of the containers for the coloring solution are shaped so that they can be heated and cooled.

18. Device according to claim 13, characterized in that, the upper lid of the dyeing reactor is formed in transverse slope, and can be heated; and in which a circular steam tube is placed to heat the interior space of the dyeing reactor.

19. Device according to claim 13, characterized in that, the dyeing reactor is equipped with a chimney with an overpressure regulator.

20. Device according to claim 13, characterized in that the hydraulic pipe system for feeding the reactor and for circulating the coloring and impregnation solution consists of the inlet pipes with a pump placed in them, as well as the valves; and in which, for the dosing of a substance that is mainly concentrated, a dosing pump with a valve is placed in an inlet.

21. Device according to claim 13, characterized in that, to ensure the uniformity of the coloring solution over the entire width of the reactor horizontal dams are placed at the entrance and at the exits. SUMMARY The invention relates to a method for the continuous dyeing of warp yarns, in particular cotton warp yarns with indigo or other groups of dyes, which require, after impregnation and squeezing, an oxidation or heat treatment for the fixation The procedure eliminates the disadvantages of traditional processes for continuous warp yarn dyeing, especially the amount required in bathrooms is reduced. Using a new dyeing reactor (1), the residence time of the warp yarns in the dyeing facility can be varied without having to increase the volume of the bath. The possibility of heating or cooling the dye bath allows to choose a fixing temperature between less than room temperature, up to greater than 100 ° C, and with this optimal conditions are achieved for all the usual warp yarn dyeing processes. By means of this, the number of immersion-oxidation processes in the indigo dyeing tub can be reduced, and with it the increasing demand of indigo blue material for jeans, with different wash resistance and pitch depths can be satisfied with greater flexibility; the same for black and colored denim.