EP0576865A1

EP0576865A1 - Method and apparatus for dyeing cellulose fiber-containing materials

Info

Publication number: EP0576865A1
Application number: EP93109044A
Authority: EP
Inventors: Hachiro c/o Technical Center Hoechst Hirooka; Takahiro c/o Technical Center Hoechst Maezono; Yoshiteru Sando; Hiroshi Ishidoshiro
Original assignee: Hoechst Mitsubishi Kasei Co Ltd; Sando Iron Works Co Ltd
Current assignee: Hoechst Mitsubishi Kasei Co Ltd; Sando Iron Works Co Ltd
Priority date: 1992-06-05
Filing date: 1993-06-04
Publication date: 1994-01-05
Also published as: TW268062B; JPH0649780A; JPH073036B2

Abstract

In order to insure that a fixing solution will be imparted to a fibrous material (6) in an optimal amount, an accompanying strip (7) that has been impregnated with the fixing solution is brought into contact with fibrous material (6) that has been dried after printing or impregnation with dyeing paste or dyeing solution while, at the same time, the fibrous material (6) and the strip (7) are pressed together so that the fixing solution is imparted to the fibrous material in an amount of 15 to 60 wt%. Thereafter, the fibrous material is steamed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for dyeing cellulose fiber-containing materials. More particularly, the invention relates to a method and apparatus for performing printing or continuous dyeing of cellulose fiber containing materials with reactive dyes in such a way that neither dye bleeding nor uneven dyeing will occur while achieving a high color yield.
In another aspect, the present invention relates to a method and apparatus for dyeing cellulose, fiber-containing materials without using urea or liquid alkali water glass as a fixing agent.

2. Description of the Related Art

The method commonly practiced to perform printing or continuous dyeing of cellulose fibers or the like with reactive dyes comprises printing the cellulose fibers or the like with a printing paste that contains the reactive dyes or padding the same fibers with a dye solution containing the reactive dyes, drying the fibers and subjecting the dried fibers to either a steaming or baking treatment. In this method, urea is preliminarily added to the printing paste or dye solution so that it will help the dye be fixed efficiently in the fiber to develop a desired color in the subsequent steaming or baking step. However, the urea containing nitrogen atoms is difficult to eliminate from the waste water and if it enters rivers and other water bodies, eutrophication can occur. Under the circumstances, there is a growing social pressure to limit the use of urea for the purpose of preventing harm to the environment.
In another method of implementing the above-described dyeing process, the fiber material (hereinafter sometimes referred to as the "substrate") is printed or impregnated with a printing paste or dye solution that does not contain a dye fixing chemical (which is hereinafter referred to simply as a "fixing agent") and, after drying, the substrate is impregnated with a solution containing fixing agents (hereinafter referred to simply as a "fixing solution") and then steamed.
Three typical methods for impregnating the substrate with the fixing solution are: (1) immersing the substrate in a bath containing the fixing solution and squeezing it between pressure rollers (imparting the fixing solution with a padder); (2) imparting the fixing solution in the form of foam; and (3) imparting the fixing solution in the form of a spray. However, the second and third methods have a problem in that the fixing solution may be imparted unevenly or it is difficult to control the amount in which the solution is imparted. Hence, the first method which relies upon a padder for imparting the fixing solution is commonly adopted.
The rate of moisture content of the substrate [(weight of water absorbed/weight of dry substrate) x 100] will increase in the steaming treatment conducted after the fixing solution is imparted to the substrate. Take, for example, the case where the substrate is a cotton satin fabric; if the rate of moisture content of the satin fabric exceeds 60%, the dye may bleed out or the percent fixation of the dye may decrease during the steaming treatment. Furthermore, the water in the steam may be deposited on the surface of the substrate and this also contributes to a higher water content of the substrate. Under the circumstances, it is desired to reduce the rate of moisture content of the yet to be steamed substrate to the lowest possible level that is not deleterious to the purpose of fixing the dye.
In fact, however, a prior art method of depositing the fixing solution by means of a padder such as the one illustrated in Fig. 6(a) is performed in such a way that a substrate 70 after being immersed within a fixing solution 71 is squeezed between mangles 72a and 72b; with this method, the fixing solution is imparted to the substrate in an amount of 70 to 130%. In other prior art methods of deposition, such as those which are illustrated in Figs. 6(b) and 6(c), the substrate 70 is not immersed directly in the fixing solution 71 and, instead, mangle 72b is submerged in the fixing solution 71 so that the latter is deposited on the surface of the mangle 72b, which is then brought into contact with the substrate. These alternative methods have the problem that the percent efficiency of imparting the fixing solution 71 is highly sensitive to its own viscosity and the rotating speed of the mangles. Hence, with these methods, the amount in which the fixing solution 71 is imparted to the substrate is usually so small that uneven color formation or insufficient color development will often occur.
Under these circumstances, liquid alkali water glass is used either alone or in admixture with sodium hydroxide to formulate the fixing solution 71, and this is well known in the art as a practice that takes advantage of the following two facts: the bound water contained in the liquid alkali water glass not only participates in the development of colors but also exhibits good buffering action on the nature of the water glass as an electrolyte and on its alkalinity. However, the liquid alkali water glass causes problems in the treatment of waste water by preventing the residual dye in the waste water from being agglomerated or by forming deposits within discharge pipes to clog them.

SUMMARY OF THE INVENTION

The present invention has been accomplished under these circumstances and has as an object providing a method for performing printing or continuous dyeing of cellulose, fiber-containing materials with reactive dyes without using urea as a dyeing auxiliary which can be a problem to environmental preservation, the method being capable of preventing the bleeding of dyes and retaining a high color yield during the steaming treatment by means of controlling the amount in which the fixing solution is imparted to the cellulose, fiber-containing material.
Another object of the present invention is to provide an apparatus for implementing this method.
A further object of the present invention is to provide a method and apparatus for dyeing cellulose fiber-containing materials using reactive dyes, that can produce dyed materials of satisfactory quality without causing the bleeding of dyes or any unevenness in colors of dyed patterns even if liquid alkali water glass, which can cause problems in the treatment of waste water by preventing the residual dye in the waste water from being agglomerated or by forming deposits within discharge pipes to clog them, is not used as a fixing agent.
The above-stated objects of the present invention can be attained by a method of dyeing a cellulose fiber-containing material which comprises printing or impregnating the cellulose, fiber-containing material with a printing paste or dye solution that comprises a reactive dye which is free of a dye fixing agent, drying the material, then imparting a dye fixing agent containing solution to the material, and subjecting the material to a steaming treatment. The method further comprises bringing an accompanying strip, which is impregnated with the dye fixing agent containing solution in such a way that the solution is imparted in an appropriate amount in accordance with the nature of the cellulose fiber-containing material, into contact with the cellulose fiber-containing material while, at the same time, pressing together the fibrous material and the strip so that the dye fixing agent containing solution is imparted to the fibrous material.
The above objects can also be attained by an apparatus, for dyeing a cellulose fiber-containing material, which comprises, as arranged in order, a unit with which the cellulose fiber-containing material is continuously transported after printed or impregnated with a printing paste or dye solution that comprises a reactive dye which is free of a dye fixing agent and thereafter dried, a fixing solution imparting unit with which a dye fixing agent containing solution is imparted to the dried cellulose fiber-containing material, and a steaming unit for steaming the cellulose fiber-containing material to which the fixing solution has been imparted. In the apparatus, the fixing solution imparting unit comprises an endless accompanying strip in the form of a running belt that is transported in the same direction as the transport of the cellulose fiber-containing material, a fixing solution impregnating means for impregnating the endless accompanying strip with the fixing solution, a press means for controlling the amount in which the endless accompanying strip is impregnated with the fixing solution, and a fixing solution contact means by which the endless accompanying strip impregnated with the fixing solution is brought under pressure into contact with the dried cellulose fiber-containing material as the latter is being transported.
The present invention is described below in greater detail.
The cellulose fiber-containing material (hereinafter referred to simply as the "fibrous material") to be used in the present invention may be exemplified by natural and regenerated cellulose fibers such as cotton, bast fibers, rayon, viscose rayon and cumrammonium rayon, as well as blends or unions of these cellulose fibers with polyester or polyamide fibers, etc.
In accordance with the present invention, printing paste free from fixing agent is first printed on the fibrous material or the material is padded with a dye solution free from a fixing agent; then, the fibrous material is dried and impregnated with a fixing solution, followed by steaming the fibrous material to have the dye fixed in the fiber.
Examples of the fixing agent that may be used in the present invention include neutral electrolytes, such as sodium chloride and sodium sulfate, and alkaline electrolytes except liquid alkali water glass, as exemplified by sodium hydroxide, sodium carbonate and potassium carbonate.
The fixing solution to be used in the case of printing contains 10 to 50 parts by weight, preferably 15 to 35 parts by weight, of sodium sulfate, 10 to 50 parts by weight, preferably 15 to 35 parts by weight, of sodium carbonate, 0 to 50 parts by weight, preferably 10 to 35 parts by weight, of potassium carbonate, and 1 to 30 parts by volume, preferably 3 to 18 parts by volume, of sodium hydroxide (38°Bé) in 1000 parts by volume of the fixing solution, with the electrolytes being contained in a total amount of 30 to 100 parts by weight, preferably 50 to 80 parts by weight.
The fixing solution to be used in the case of continuous dyeing contains 30 to 90 parts by weight, preferably 45 to 75 parts by weight, of sodium sulfate, 10 to 60 parts by weight, preferably 30 to 50 parts by weight, of sodium carbonate, and 5 to 30 parts by volume, preferably 8 to 15 parts by volume, of sodium hydroxide (38° Bé) in 1000 parts by volume of the fixing solution, with the electrolytes being contained in a total amount of 30 to 140 parts by weight, preferably 50 to 120 parts by weight.
It is also preferred for the fixing solution to have a specific gravity of 1.1 to 1.3 and a pH of 10 to 13. The heretofore used fixing solutions have contained fixing agents in a total amount of 200 to 300 parts by weight in 1000 parts by volume of the fixing solution; in contrast, the present invention permits the use of fixing solutions having much lower concentrations and, hence, is advantageous from an economic viewpoint.
The fixing solution described above is impregnated in the accompanying strip which may be formed of any materials that are capable of sufficient water retention to permit impregnation with the fixing solution but which are not dyeable. Examples of useful materials are knitted or woven fine denier fabrics of natural, synthetic or metal fibers or those polyester based materials which are generally referred to as "Shin-gosen" and which are impregnable with the fixing solution, such as a raised tricot jersey fabric or tricot satin fabric that are produced by knitting front and back yarns, the front yarns being formed of split composite fibers made from nylon 6 and polyethylene terephthalate and the back yarns being formed of polyethylene terephthalate fibers.
In order to have the fixing solution impregnated in the accompanying strip, the latter is immersed in a bath containing the fixing solution and, thereafter, the strip is recovered from the bath and pressed by a pressure applying means such as pressure rollers so as to adjust the amount in which the fixing solution is to be impregnated in the strip. In an exemplary case, the fixing solution is impregnated in the accompanying strip and, with the pressure rollers being set to apply a pressure of 0.5 to 3.5 kg/cm², the accompanying strip is pressed in such a way that it is impregnated with the fixing solution in an amount ranging from 80 to 120 wt% of the weight of the dried strip made of natural or synthetic fibers and in an amount ranging from 20 to 50 wt% of the weight of the dried strip made of metal fiber.
Subsequently, the accompanying strip thus impregnated with the fixing solution is brought into contact with the fibrous material while, at the same time, the two members are pressed together so that the fixing solution is imparted to the fibrous material. The amount in which the fixing solution is imparted to the fibrous material is adjusted by controlling the amount of the fixing solution to be impregnated in the accompanying strip. Hence, the amount of the fixing solution which is to be imparted to the fibrous material can be controlled by adjusting that the pressure for pressing the accompanying strip after it has been impregnated with the fixing solution is adjusted to lie within the range of 0.5 to 3.5 kg/cm² as mentioned in the preceding paragraph. Depending on the yarn count of the fibers constituting the fibrous material and on the fiber structure, the amount of the fixing solution to be imparted to the fibrous material is generally in the range from 15 to 60 wt%, preferably from 20 to 50 wt%, more preferably from 30 to 45 wt%, of the dried fibrous material in the case of printing; in the case of continuous dyeing, the amount in question is generally in the range from 30 to 60 wt%, preferably from 35 to 50 wt%. If the amount of the fixing solution to be imparted to the fibrous material is less than 15 wt%, the dye may be fixed insufficiently to prevent uneven dyeing. If the amount of interest exceeds 60 wt%, the dye will bleed out or the color yield will decrease. Table 1 shows the relationship between the pick up (percent impregnation) of the fixing solution in the accompanying strip (raised fabric obtained by knitting fine denier split composite fibers made from nylon 6 and polyethylene terephthalete as front years and fine denier fibers made of polyethylene terephthalate as back yarns) and the percent efficiency of imparting the fixing solution to the various fibrous materials at a pressure of 3.0 kg/cm² at which both fibrous material and accompanying strip were pressed, while varying values of the pressure at which the fixing solution was impregnated in the accompanying strip. The pressure at which the fibrous material and the accompanying strip impregnated with the fixing solution are pressed together is usually selected from the range 2.0 to 4.0 kg/cm².
After imparting the fixing solution, the fibrous material is steamed for 15 to 90 sec., preferably 30 to 60 sec., thereby fixing the dye in the fibrous material. If the steaming time is shorter than 15 sec., the dye will be fixed insufficiently. Even if the steaming time is longer than 90 sec., the rate of dye exhaustion will not be improved significantly but, on the contrary, it may sometimes drop. The steaming time longer than 90 sec. is also uneconomical from the viewpoint of thermal energy.
According to the present invention, a printing paste or dye solution, that comprises a reactive dye free from fixing agents, is printed or padded in a fibrous material and, after drying the fibrous material, a fixing solution is imparted to the material in such a way that the volume of the fixing solution to be impregnated in the accompanying strip is adjusted at a desired level while, at the same time, the accompanying strip is transported in the same direction as the transport of the dried fibrous material, whereby the accompanying strip is brought into contact with the dried fibrous material as the two members are pressed together so that the fixing solution will be imparted to the fibrous material in an optimal amount depending upon the species of the fibrous material.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a schematic side view of one embodiment of the dyeing apparatus according to the present invention, with particular reference made to the fixing solution imparting unit portion and the steamer portion;
Fig. 2 shows a schematic side view of another embodiment of the dyeing apparatus according to the present invention, also with respect to the fixing solution imparting unit portion and the steamer portion;
Fig. 3 shows an enlarged view of one example of the fixing solution imparting unit used in the present invention;
Fig. 4 shows an enlarged view of one example of the steamer used in the present invention;
Fig. 5. shows an alternative embodiment of the dyeing apparatus of the present invention in which the press and the fixing solution contact means form an integral assembly; and
Figs. 6(a)-6(c) show the conventional fixing solution imparting unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention are described below with reference to the accompanying drawings.
The dyeing apparatus according to the first and second embodiments is shown in Figs. 1 and 2, respectively; the fixing solution imparting unit is generally indicated by 1 and an enlarged schematic view of the unit 1 according to the first embodiment is shown in Fig. 3, whereas the steamer is generally indicated by 2 and an enlarged schematic view of a steamer for use in either the first or second embodiment is shown in Fig. 4.
The fixing solution imparting unit 1 consists of two zones 3 and 5. Zone 3 comprises a fixing solution contact means 13 by which a fibrous material 6 (hereinafter sometimes referred to as a "substrate") that has been dried after printing or continuous dyeing is brought into contact with the accompanying strip 7 impregnated with a fixing solution. Zone 5 is an accompanying strip transport zone and comprises respective means for impregnating the fixing solution in the accompanying strip 7, cleaning the strip 7 from which the fixing solution has been imparted to the substrate 6, and dehydrating the strip.
The accompanying strip transport zone 5 comprises, as arranged in the following order, a plurality of rolls 9 for transporting the accompanying strip 7 in the form of an endless belt, the associated drive mechanism (not shown), a fixing solution impregnator 10 for immersing the strip 7 in the fixing solution so that it is impregnated in the strip 7, a press 11 that applies pressure to control the amount of the fixing solution that is impregnated in the strip 7, a washer 14 for the strip 7 from which the fixing solution has been imparted to the dry substrate 6, and a dehydrator 15 of the cleaned strip 7. The strip 7, in the form of an endless belt, is transported into the above means for circulation therethrough.
The fixing solution impregnator 10 has a tank 12 for containing the fixing solution, which, as described below, has been adjusted in type and concentration in accordance with the material, yarn count, fiber structure and other characteristics of the specific substrate to be dyed. A transport roll 12a for the strip 7 is provided near the bottom of the tank 12 so that the strip 7 is fully immersed in the fixing solution as it is transported via the roll 12a.
After impregnation with the fixing solution, the strip 7 is passed between a pair of pressure rolls 17a and 17b in the press 11 and the pressure applied between these rolls is so adjusted that the fixing solution can be impregnated in the strip 7 in an amount suitable for the substrate 6. In a typical case, the strip 7 is pressed until it is impregnated with the fixing solution in an amount of about 80 to 120 wt% of the strip. For adjusting the force of pressure as applied between the pair of rolls 17a and 17b, the following method is adopted: one of the two rolls, for example, roll 17a, is secured to a table and a lever 17c is secured to the rotating shaft of the other roll 17b; the lever 17c is connected to a diaphragm rubber cylinder 17d which causes the lever 17c to be actuated on its fulcrum (not shown) at the center.
The fixing solution contact means 13 is also composed of a pair of pressure rolls 18. The dried substrate 6 and the accompanying strip 7 are transported in the same direction and passed between the two rolls 18 in such a way that they contact each other. The force of pressure acting between the pair of rolls 18 causes the impregnated fixing solution to be imparted from the strip 7 to the substrate 6. The pressure between the rolls 18 is preset at a given value and the amount of the fixing solution to be imparted to the substrate 6 can be controlled by adjusting the amount in which it is impregnated in the strip 7 pressed by the press 11.
An important feature of the present embodiment is in the press 11 and the fixing solution contact means 13, the combination of which enables the fixing solution to be imparted to the substrate 6 in an amount of 15 to 60 wt%. Transferring the fixing solution onto the substrate 6 via the accompanying strip 7 in the manner described above offers the advantage in that the fixing solution can be imparted to the substrate 6 in an optimal quantity that matches the material, yarn count, fiber structure and other characteristics of the substrate 6.
If necessary, the press 11 and the fixing solution contact means 13 may form an integral assembly as shown in Fig. 5. In this case, three rolls 20a, 20b and 20c will suffice and, in addition, the drive power only needs to be transmitted to the center roll 20b for causing the pressing rolls 20a/20b and the fixing solution contact rolls 20b/20c to rotate at the same time. As shown in Fig. 5, one of the three rolls, for example, 20b is secured to a table and pressure levers 21a and 21b are mounted on the other rolls 20a and 20c, respectively; the levers 21a and 21b are respectively connected to pneumatic pressure cylinders 22a and 22b, and air is introduced into the respective cylinders, so that the pressure acting between rolls 20a and 20b and between rolls 20b and 20c can be adjusted by motion of the levers.
The strip 7 from which the fixing solution has been imparted to the substrate 6 is then transported to the washer 14. Although not shown, the washer 14 is furnished with temperature-controlled steam heating pipes, cooling water pipes, overflows, etc. The washer 14 also has a tank 16 for a cleaning solution that is composed of water that may contain a detergent and other optimal ingredients. A plurality of transport rolls 9 for the accompanying strip 7 are provided near the bottom of the tank 16 and the strip 7 can be cleaned thoroughly as it is transported in a zigzag path between those transport rolls 9.
The dehydrator 15 consists of a pair of pressure rolls, between which the cleaned strip 7 is passed for dehydration.
The substrate 6 to which the fixing solution has been imparted is then transported to the steamer 2. The steamer 2 has an entrance 30 for the substrate 6 provided in the bottom at one end; it also has an exit 31 for the substrate provided at the other end at the bottom. A row of substrate transport rolls 32 are arranged in the upper portion of the steaming space between the substrate entrance 30 and exit 31. The first substrate transport roll 32a which is the closest to the entrance 30 ensures that the substrate 6 emerging from the fixing solution imparting unit 1 is properly guided into the steamer 2. The transport rolls 32 are driven in such a controlled manner (for details, see below) that the substrate 6 is transported toward the exit 31 as it is hung over the sequence of transport rolls 32. Therefore, as shown in Figs. 1 and 2, the substrate 6 is transported in a serpentine path (it droops between adjacent transport rolls 32) and as the substrate 6 is transported in this way, it is heated sufficiently to achieve satisfactory dye fixation.
The means of transporting the substrate within the steamer 2 in the embodiment under consideration is optimal for the method of dyeing only one side of the substrate as in printing. In this case, only the side of the substrate that does not come in contact with the rolls 32 is printed, thus permitting the substrate to be dyed to produce a good finish without being stained by the rolls 32. Needless to say, the transport means is also applicable to dyeing both sides of the substrate as in plain dyeing.
In order to insure that the substrate 6 will be transported in a serpentine path as it droops between adjacent rolls 32, the surface of each roll 32 is subjected to an anti-slip treatment that will provide a higher friction coefficient. Examples of such an anti-slip treatment include providing a number of spikes over the entire surface of the rolls 32, as well as covering the rolls with a coating of plastics, metals or other materials having a high friction coefficient.
All transport rolls 32 except the first roll 32a and the subsequent second roll 32b are provided with auxiliary rolls 33 that are located near the rolls 32 in a position upstream of the rolls 32 with respect to the direction of substrate transport to insure that the drooping substrate during transport is folded back and positively transferred to the next roll 32. On the other hand, all transport rolls 32 including the first and second rolls are provided with auxiliary rolls 34 that are located near the rolls 32 in a position downstream in the direction of substrate transport to insure that the substrate 6 will not wind itself around the rolls 32 having a high friction coefficient.
An endless belt 35 runs over the second transport roll 32 so as to form a transport path that is inclined toward the first transport roll 32a. Two units 37ax and 37ay of a first sensor 37a for substrate detection are provided vertically in a position that is below the first transport roll 32a and which face the endless belt 35. Two units 37x and 37y of a substrate detecting sensor 37 are also provided vertically for the second and subsequent transport rolls 32 in a position that is below the space between adjacent rolls.
The sensors 37 may be of any type that is capable of detecting the substrate 6, as exemplified by photosensors, touch sensors, etc. In the present embodiment, sensors 37a and 37b are photosensors and sensor 37z is a touch sensor.
A plurality of openable inspection doors 38 are provided, as required, in the side wall of the steamer 2.
The steamer 2 is supplied with steam that is blown in through a plurality of inlets 39 which are provided uniformly along the entire length of the bottom of the steamer 2 in such a way that they are arranged in the direction of substrate transport. Pressure-controlled steam from a boiler (not shown) is blown into the steamer 2. Steam deflecting covers (not shown) are provided above the steam inlets 39 to insure that the steam gushing out of the inlets will not make direct contact with the substrate.
Drain baffle walls 30a and 31a are provided within the steamer 2 around the entrance 30 and exit 31, respectively, to insure that steam condensate will not leak out of the steamer 2 through the entrance 30 and the exit 31. Steam chambers 41 and 42 are provided on the side of the exterior wall of the steamer 2 away from the drain baffle walls 30a and 31a, respectively; the steam discharged through the entrance 30 and exit 31 will stay temporarily in the chambers 41 and 42 and then it passes through riser pipes 43 and 45 that run on the outer surface of the side wall of the steamer 2 before the steam is eventually discharged to ambient through exhaust fans 46 and 47. Dampers 49 and 50 are provided approximately halfway along the pipes 43 and 45, respectively, and by adjusting the degree of their opening, the quantity of steam present in the steamer 2 can be controlled. The quantity of steam in the steamer 2 is detected with a pressure sensor (not shown) and a signal for the detected value is transmitted to damper controls (not shown).
Next, the method of controlling the substrate 6 so that it is transported in a serpentine path through the steamer 2 is described with reference to Fig. 4. First, the leading edge of the substrate 6 to be dyed is connected by sewing to a guide cloth that is preliminarily stretched over all rolls 32 in the steamer 2. Then, the substrate 6 as it is guided by the cloth is fed into the steamer 2 through the entrance 30. When the interior of the steamer 2 is fully saturated with steam, the individual transport rolls 32 start to be driven. If the leading edge of the substrate 6 is detected by the first sensor 37a, the endless belt 35 to the second roll 32b starts to be driven, causing the substrate 6 to be transported with its leading edge folded back toward the transport roll 32b. If the second sensor 37b between the second transport roll 32b and the third transport roll 32c detects the drooping of the substrate, the third transport roll 32c will start to rotate. In this way, transport rolls positioned downstream of the direction of substrate transport start to rotate successively and the substrate will be transported as it droops between adjacent transport rolls 32.
The printed fabric entering the steamer 2 may have already gained a moisture content; however, on account of the printing paste, the fabric is hard and lacks suppleness; hence, it might swing in the direction of transport when it bends. The endless belt 35 is provided in order to prevent the occurrence of such a swing.
The sensors 37 provided between the second transport roll 32b and subsequent rolls 32 are capable of controlling the rotating speeds of the associated rolls 32 to insure that the folded portions of the substrate 6 will always be positioned within the range that can be detected by the upper and lower rows x and y of sensors.
With the droop width of the substrate 6 being controlled in the manner described above, the time for which the substrate 6 stays within the steamer 2 can be adjusted to an optimal value in accordance with the material of the substrate or the method of dyeing it. It should be noted here that the transport of the substrate 6 in a serpentine path is controlled by the associated control unit (not shown).
In Fig. 1, the steamer 2 is positioned directly over the fixing solution imparting unit 1, such that the apparatus can be small in size and the overall length. However, in the alternative embodiment of Fig. 2, the steamer 2 is positioned offset with respect to the fixing solution imparting unit 1, such that the substrate 6 can be steamed shortly after being in pregnation with the fixing solution.
Several examples of dyeing the substrate by the claimed method of the present invention using the claimed apparatus of the invention are described below. Unless otherwise noted, all "parts" and "%" that appear in the following "examples", "reference examples" and "comparative examples" are on a weight basis.

Reference Example 1

(Single-phase printing using urea-containing printing paste)

Using the dyes listed below under (1), printing pastes were prepared according to the formulae shown in Tables 2 and 3. Mercerized cotton satin fabrics (120 g/m²) were printed with those pastes, dried, steamed in a steamer at 103°C for 5 min, washed with cold water, then with warm water, and further cleaned with boiling water having 2 g of a nonionic surfactant (available under the tradename "HOSTAPAL CT-40" from Hoechst AG) dissolved in a liter of water. The reflectance of the dried fabric after dyeing was measured with the Macbeth MS 2020 PLUS (Macbeth Instrument Corporation) and the apparent strength of each dyed fabric was determined by the following equation (1):

where $\bar{x}$
, $\bar{y}$
, $\bar{z}$
represent color matching functions, and

$K/S = (1-R)²/2R (R: reflectance)$
.

(1) Dyes used (all being manufactured by Mitsubishi Kasei Hoechst Co., Ltd.; "REMAZOL" is the registered trademark of Hoechst AG and "DIAMIRA" is the registered trademark of Mitsubishi Kasei Corp.)
- (a) Remazol/Diamira Brilliant Yellow GL (C.I. Reactive Yellow 37)
- (b) Remazol/Diamira Brilliant Orange 3R (C.I. Reactive Orange 16)
- (c) Remazol/Diamira Brilliant Red BB (C.I. Reactive Red 21)
- (d) Remazol/Diamira Blue R-KN (C.I.Reactive Blue 19)
- (e) Remazol/Diamira Turquoise Blue G (C.I.Reactive Blue 21)
- (f) Remazol/Diamira Black B (C.I. Reactive Black 5)

TABLE 2

Printing Paste
Component	Parts by weight
Dye	4^*1
Urea	10
Chelating agent^*2	0.5
Antireductant^*3	1
Stock paste^*4	60
Sodium bicarbonate	2
Water	balance
Tatal	100

*1 Dye (f) was used in an amount of 6 parts.
*2 Sodium hexametaphosphate
*3 Sodium metanitrosulfonate (available from Meisei Chemical K.K. under the tradename "MS POWDER")
*4 Component of Stock paste

TABLE 3

Stock Paste
Component	Parts by weight
Sodium alginate (available from Kibun, K.K. under the tradename "DAK ARUGIN NSPM)	4
Aliphatic acid/polyglycol ester (available from Hoechst AG under the tradename "EMULSIFIER DMR")	0.25
Mineral terpene	0.8
Water	balance
Total	100

Example 1

Using the same dyes as used in Reference Example 1, as well as dyeing auxiliaries, printing pastes were prepared according to the formula shown in Table 4. Cotton satin fabrics of the same kind as used in Reference Example 1 were printed with those pastes and dried. In a separate step, a fixing solution was prepared according to the formula shown in Table 5. An accompanying strip (split composite fibers made of nylon 6 and polyethylene terephthalate were knitted or woven in combination with polyethylene terephthalate yarns and the fabric was raised) was immersed in the fixing solution and thereafter pressed at 1.5 kg/cm² with the press 11 (see Fig. 3) to achieve 94% impregnation of the fixing solution. The strip 7 impregnated with the fixing solution was fed into the fixing solution contact means 13 where it was brought into contact with the dried cotton satin fabrics while, at the same time, the two members were pressed together at a pressure of 3 kg/cm². The fixing solution was imparted to the cotton satin fabrics in an amount of 40%.

Subsequently, the dyed fabrics were steamed in the steamer 2 at 103°C for 60 sec., washed with cold water, then with warm water; thereafter, as in Reference Example 1, the fabrics were cleaned with boiling water containing a surfactant. The apparent strength of each dyed fabric was determined by the same method as adopted in Reference Example 1. The results are listed by dye in Table 7 in terms of relative values, with the apparent strengths of the dyed fabrics of Reference Example 1 being taken as 100.

Table 4

Printing Paste
Component	Parts by weight
Dye	4^*1
Chelating agent^*2	0.5
Antireductant^*3	1
Stock paste^*4	65
Water	balance
Total	100
1 to 4: See notes to Reference Example 1.

Table 5

Fixing Solution
Component	Proportion
Sodium sulfate	33.3 parts by weight
Sodium carbonate	33.3 parts by weight
Sodium hydroxide (38°Bé)	3.3 parts by volume
Water	balance parts by volume
Total	1000 parts by volume

Comparative Example 1

Cotton satin fabrics of the same kinds as used in Example 1 were printed with pastes of the same formula as used in Example 1. The printed fabrics were dried, immersed in a fixing solution having the formula shown in Table 6, and mangled at a pressure of 2.5 kg/cm². The fixing solution was imparted to each cotton satin fabric in an amount of 103%. Subsequently, the fabrics were steamed at 103°C for 10 sec., followed by washing first with cold water, then with warm water and cleaning with boiling water as in Example 1. The apparent strength of each dyed fabric was measured by the same method as adopted in Example 1. The results are listed by dye in Table 7 in terms of relative values, with the apparent strengths of the dyed fabrics of Reference Example 1 being taken as 100. The dyes were found to bleed out in Comparative Example 1.

Table 6

Fixing Solution
Component	Proportion
Sodium chloride	100 parts by weight
Sodium carbonate	100 parts by weight
Potassium carbonate	100 parts by weight
Sodium hydroxide (38°Bé)	100 parts by volume
Water	balance parts by volume
Total	1000 parts by volume

Example 2 and Reference Example 2

In Example 2, printing was carried out using the same pastes, fixing solution and dyeing apparatus as employed in Example 1, except that the cotton satin fabrics were replaced by alkali-treated viscose rayon fabrics (110 g/m²).
In Reference Example 2, printing was carried out by repeating the procedure of Reference Example 1 except that the cotton satin fabrics were replaced by alkali-treated viscose rayon fabrics (110 g/m²).
The apparent strengths of the fabrics dyed in Example 2 are listed by dye in Table 7 in terms of relative values, with the apparent strengths of the dyed fabrics of Reference Example 2 being taken as 100. Table 7

Apparent Strength

Dye Example 1 Comparative Example 1 Example 2

(a) 105 100 108

(b) 100 99 110

(c) 115 109 122

(d) 108 104 114

(e) 93 88 112

(f) 108 103 110

Example 3 and Reference Example 3

In Example 3, a padding solution was prepared according to the formula listed in Table 8, Mercerized cotton satin fabric (120 g/m²) was padded with that solution and dried. Thereafter, a resist printing paste of the formula listed in Table 9 was printed on the dried substrate, dried and steamed at 103°C for 5 min. In a separate step, a fixing solution was prepared according to the formula listed in Table 10. An accompanying strip 7 of the same kind as used in Example 1 was immersed in that fixing solution and pressed at 1.0 kg/cm² by means of the press 11 (see Fig. 3) until the strip 7 was impregnated with 106% fixing solution. The strip 7 thus impregnated with the fixing solution was fed into the fixing solution contact means 13 where it was brought into contact with the steamed substrate and the two members were pressed together at a pressure of 3.0 kg/cm², whereby the fixing solution was imparted to the substrate in an amount of 49%. The substrate was further steamed at 103°C for 45 sec. and then treated as in Example 1. Thereafter, the apparent strength of the dyed fabric was determined. Table 8

Padding Solution

Component Parts by weight

Dye^*1 4

Chelating agent^*2 0.1

Antireductant^*3 1

Antimigration agent ^*4 10

Water balance

Total 100

*1 Remazol/Diamira Black B

*2, *3 See notes to Reference Example 1.

*4 Dak Arugin NSPM in 1% aq. sol.

Table 9

Resist printing paste
Component	Parts by weight
Dye
^*6	1
Acidic sulfite-base resisting agent ^*7	3
Chelating agent^*8	0.1
Sodium carbonate	2
Stock paste^*9	65
Water	balance
Total	100

*6 CIBACRON Yellow 6GS (product of Ciba-Geigy AG; C.I. Reactive Yellow 95; "CIBACRON" is the registered trademark of Ciba-Geigy AG)
*7 Available from Meisei Chemical K.K. under the tradename "RESISTOL HWS"
8, 9 See notes to Reference Example 1.

Table 10

Fixing Solution
Component	Proportion
Sodium sulfate	58.7 parts by weight
Sodium carbonate	39.1 parts by weight
Sodium hydroxide	11.7 parts by weight
Water	balance parts by volume
Total	1000 parts by volume

A cotton satin fabric was dyed by repeating the procedure of Example 3 except that a urea-loaded padding solution of the formula listed in Table 11 was used and that the fabric printed with resist printing paste was steamed for 10 min (Reference Example 3).

A apparant strength of the fabric dyed in Example 3 of 107 was in term of relative value, with the apparent strength of the dyed fabric of Reference Example 3 being taken as 100.

Table 11

Padding Solution
Component	Parts by weight
Dye^*1	4
Urea	5
Chelating agent^*2	0.1
Antireductant^*3	1
Antimigration agent ^*4	10
Alkali generator ^*10	10
Water	balance
Total	100
1 to 4 See notes to Example 3.

*10 Na salt of chlorinated carboxylic acid (available from Hoechst AG under the tradename "REMAZOL SALT FD") in 50% ag. sol.

Example 4 and Comparative Example 2

To 75 parts of Remazol/Diamira Brilliant Red BB liq. 40 (product of Mitsubishi Kasei Hoescht Co., Ltd.; C.I. Reactive Red 21) were added 100 parts of Dak Arugin NSPM (antimigration agent) in 1% aqueous solution, 10 parts of MS Powder (antireductant) and a specialty anion-nonion blend (penetrant available from Hoescht AG under the tradename "RHEONEEL SRJ"). Water was also added to prepare a dye solution in a total amount of 1000 parts by volume. A mercerized cotton twill fabric (180 g/m²) was immersed in that dye solution, pressed to a pickup of about 70% and baked at 120°C for 3 min.
In a separate step, 58.7 parts of sodium sulfate, 39.1 parts of sodium carbonate and 11.7 parts by volume of sodium hydroxide (38° Bé) were mixed and water was added to the mixture to prepare a fixing solution weighing a total of 1000 parts by volume. An accompanying strip 7 of the same kind as used in Example 1 was immersed in the fixing solution and pressed at a pressure of 0.9 kg/cm² to attain 115% impregnation of the fixing solution. The so impregnated strip was fed into the fixing solution contact means 13 (see. Fig. 3), where it was brought into contact with the baked cotton twill fabric while, at the same time, the two members were pressed together at a pressure of 3.0 kg/cm² to insure that the fixing solution was imparted to the cotton twill fabric in an amount of 53%. Thereafter, the fabric was steamed at 103°C for 45 sec. and further cleaned as in Example 1.
In Comparative Example 2, a cotton twill fabric was immersed in a dye solution, pressed and dried as in the above-described Example 4. In a separate step, 200 parts of sodium sulfate, 40 parts of sodium carbonate and 15 parts by volume of sodium hydroxide (38° Bé) were mixed together. Water was added to the mixture to prepare a fixing solution in a total amount of 1000 parts by volume. The dried twill fabric after immersed in a dyeing solution and pressed as in Example 4 was immersed in the fixing solution and mangled at a pressure of 2.5 kg/cm² so that the fixing solution would be imparted to the fabric in an amount of 78%. The dyed fabric was subsequently processed as in Example 4.
The fabric dyed in Example 4 and Comparative Example 2 were measured for their apparent strength; the apparent strength of the fabric dyed in Example 4 was 104 on either side, with the value for the dyed fabric of Comparative Example 2 being taken as 100.
According to the present invention, an accompanying strip that has been impregnated with a fixing solution is transported in the same direction as the transport of a fibrous material that has been printed or impregnated with dye and thereafter dried. During the transport, the strip is brought into contact with the fibrous material while, at the same time, the two members are pressed together, whereby the fixing solution can be imparted to the fibrous material in an optimal amount that matches the nature of the fibrous material.
The dyeing method of the present invention also offers an economic advantage since compared to the conventional methods of imparting fixing solutions, the method of the invention permits the use of a fixing solution containing a smaller amount of dye fixing agent and, furthermore, the fixing solution may be imparted to the fibrous material in a smaller quantity.
In addition, the fixing solution can be imparted to the fibrous material in an optimal amount and, hence, not only is it possible to prevent the occurrence of dye bleeding while retaining a high color yield, but one can also print or pad-dye the substrates in a consistent way to yield better quality.
The present invention offers yet another advantage, from the standpoint of both operational efficiency and environmental preservation, in that dyed fabric can be produced without dye bleeding or unevenness in dye strength even if neither urea nor liquid alkali water glass is used.
Although the present invention has been fully described by way of the preferred embodiments thereof with reference to the accompanying drawings, various changes and modifications will apparent to those having skill in this field. Therefore, unless these changes and modifications otherwise depart from the scope of the present invention, they should be construed as included therein.

Claims

A method of dyeing a cellulose fiber-containing material, said method comprising the steps of: printing or impregnating the cellulose fiber-containing material with one of a printing paste and a dye solution that comprises a reactive dye which is free of a dye fixing agent; drying said cellulose fiber-containing material; then imparting a dye fixing agent containing solution to said cellulose fiber-containing material and subjecting said cellulose fiber-containing material to a steaming treatment; said method further comprising bringing an accompanying strip, which is impregnated with the dye fixing agent containing solution in such a way that the dye fixation-containing solution is imparted in a predetermined amount in accordance with the nature of said cellulose fiber-containing material, into contact with said cellulose fiber-containing material while, at the same time, pressing together said cellulose fiber-containing material and said accompanying strip so that the dye fixing agent containing solution is imparted to said cellulose fiber-containing material.
The method of dyeing according to claim 1, wherein the printing paste, which comprises the reactive dye that is free of a dye fixing agent, is printed on the cellulose fiber-containing material, which is then dried, followed by imparting the dye fixing agent containing solution in an amount of 15 to 60 wt% of the dried cellulose fiber-containing material.
The method of dyeing according to claim 2, wherein the dye fixing agent containing solution contains 10 to 50 parts by weight of sodium sulfate, 10 to 50 parts by weight of sodium carbonate, 0 to 50 parts by weight of potassium carbonate and 1 to 30 parts by volume of sodium hydroxide (38° Bé) in 1000 parts by volume of said dye fixing agent containing solution.
The method of dyeing according to claim 1, wherein the cellulose fiber-containing material is impregnated with the dye solution, which comprises the reactive dye that is free of dye fixing agent and dried, followed by imparting the dye fixing agent containing solution in an amount of 30 to 60 wt% of the dried cellulose fiber-containing material.
The method of dyeing according to claim 4, wherein the dye fixing agent containing solution contains 30 to 90 parts by weight of sodium sulfate, 10 to 60 parts by weight of sodium carbonate and 5 to 30 parts by volume of sodium hydroxide (38° Bé) in 1000 parts by volume of said dye fixing agent containing solution.
An apparatus for dyeing a cellulose fiber-containing material, said apparatus comprising: a transport unit with which the cellulose fiber-containing material is one of printed and impregnated with one of a printing paste and a dye solution, which comprises a reactive dye that is free of a dye fixing agent, and thereafter the cellulose fiber-containing material is dried for continuous transport; a fixing solution imparting unit with which a dye fixing agent containing solution is imparted to said dried cellulose fiber-containing material; and a steaming unit for steaming the cellulose fiber-containing material to which said dye fixing agent containing solution has been imparted; wherein said fixing solution imparting unit comprises an endless accompanying strip that is transported in the same direction as a transport direction of said cellulose fiber-containing material, a fixing solution impregnating means for impregnating said endless accompanying strip with the dye fixing agent containing solution, a press means for controlling the amount in which the endless accompanying strip is impregnated with the dye fixing agent containing solution, and a fixing solution contact means by which the endless accompanying strip impregnated with the dye fixing agent containing solution is brought under pressure into contact with the dried cellulose fiber-containing material as the dried cellulose fiber-containing material is being transported.
The dyeing apparatus according to claim 6, wherein said press means comprises a pair of pressure rolls and a mechanism for controlling a force of pressure applied between said pressure rolls, and said fixing solution contact means comprises a pair of rolls that are operative to apply a predetermined pressure.