Patent Publication Number: US-2012023685-A1

Title: Fabric Dyeing Apparatus and Method

Description:
FIELD OF THE INVENTION 
     The present invention relates to a fabric dyeing apparatus and method. Such an apparatus and/or method may be useful for saving time, materials, and cost related to dyeing fabric. 
     BACKGROUND OF THE INVENTION 
     Conventional commercial fabric dyeing processes can have certain economic, quality control, environmental, and other disadvantages. For example, the ratio of dye bath mixture-to-fabric in a conventional fabric dyeing process can be about 10:1, resulting in a high cost for water and chemical additives in the dye bath mixture. Another disadvantage is that, although “reactive dyeing” processes may provide greater color fastness and quality control, “direct dyeing” processes can be less expensive and are thus often used to dye fabric, resulting in lower quality products. When conventional “reactive dyeing” processes are employed to dye fabric in a commercial setting, processing time can be six hours or longer, which decreases productivity. Another disadvantage is that a fabric dyeing apparatus is often configured to include separate compartments for processing a load of fabric from one step to another, which can require separately heating each chamber for different processing steps, thereby increasing processing costs. 
     In addition, expensive conventional fabric bleaching tunnels may sit idle while the need for dyeing large loads of fabric exists. Therefore, potential resources for dyeing fabric can go unused. 
     Thus, there is a need for a fabric dyeing apparatus and/or method having a lower ratio of dye bath mixture-to-fabric than required in a conventional fabric dyeing process so as to decrease the cost of water in the dye bath mixture. There is a need for such an apparatus and/or method that utilizes “reactive dyeing” processes in order to provide greater color fastness and quality control. There is a need for such an apparatus and/or method that utilizes “reactive dyeing” processes having a processing time substantially less than six hours as employed in conventional fabric dyeing processes. There is a need for such an apparatus and/or method that utilizes a conventional bleaching tunnel converted to accommodate fabric dyeing. 
     SUMMARY 
     Some embodiments of the present invention can include a fabric dyeing apparatus and/or method. In some embodiments, a fabric dyeing apparatus can include a tunnel comprising a plurality of chambers through which a load of fabric is successively transferred. A first set of the plurality of chambers can comprise a consecutive series of dye chambers through which the fabric load and a single dye bath are successively transferred, in which the dye bath is heated to about the same temperature in each of the dye chambers, and in which the fabric load is exposed to the dye bath for about 35 minutes to about 60 minutes. A first chamber in the series of dye chambers and each chamber subsequent to the dye chambers can be adapted to receive a fresh water bath. A last chamber in the series of dye chambers and each subsequent chamber can be adapted to drain the bath in those chambers. 
     In some embodiments of the fabric dyeing apparatus, the weight ratio of dye bath mixture-to-fabric can be about 5:1. In some embodiments, the dye bath can comprise a fiber reactive dye or a direct fiber dye. Such an apparatus can be utilized to effectively dye a fabric comprising cotton or a cotton blend. 
     In some embodiments, the tunnel comprising the fabric dyeing apparatus can be a modified bleaching tunnel. For example, the fabric dyeing apparatus can comprise a 15-chamber bleaching tunnel. Such a bleaching tunnel can be adapted to bleach the fabric load in one cycle through the plurality of chambers and dye the fabric load in another cycle through the plurality of chambers. 
     The present invention can include embodiments of a method of dyeing a fabric and/or fabric product. Such a method of dyeing a fabric can utilize all or portions of the fabric dyeing apparatus described herein. For example, in some embodiments, a fabric bleaching tunnel comprising a plurality of chambers can be modified to receive a dye bath in a first set of selected chambers and to drain the bath in a second set of selected chambers such that a load of fabric can be successively transferred through the plurality of chambers. In this way, the bleaching tunnel is capable of dyeing fabric. 
     In some embodiments of the fabric dyeing method, the weight ratio of dye bath mixture-to-fabric can be about 5:1. In certain embodiments, the fabric load can be processed through the apparatus in about two hours. Such methods can further include bleaching the fabric load in one cycle through the plurality of chambers and dyeing the fabric load in another cycle through the plurality of chambers. 
     Features of a fabric dyeing apparatus and/or method may be accomplished singularly, or in combination, in one or more of the embodiments of the present invention. As will be realized by those of skill in the art, many different embodiments of a fabric dyeing apparatus and/or method are possible. Additional uses, advantages, and features of aspects of the present invention are set forth in the illustrative embodiments discussed in the detailed description herein and will become more apparent to those skilled in the art upon examination of the following. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic illustration of a fabric dyeing apparatus in an embodiment of the present invention. 
         FIG. 2  is a chart identifying the additives, temperature, and cycle time in each of the chambers of the fabric dyeing apparatus shown in  FIG. 1 , for dyeing fabric in an embodiment of a reactive dyeing process of the present invention. 
         FIG. 3  is a chart identifying the additives, temperature, and cycle time in each of the chambers of the fabric dyeing apparatus shown in  FIG. 1 , for dyeing fabric in an embodiment of a direct fabric dyeing process of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     For the purposes of this specification, unless otherwise indicated, all numbers expressing quantities, conditions, and so forth used in the specification are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification are approximations that can vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. 
     Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. 
     As used in herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, the term “a dye bath” is intended to mean a single dye bath or a combination of dye baths. 
     As used herein, the term “fabric” means fabric and/or fabric product. For example, “fabric” can refer to a piece of textile material that has not been made into a product and/or to a fabric product, such as a sock, comprising a piece of textile material. Some embodiments of the present invention can provide a fabric dyeing apparatus and/or method.  FIGS. 1-3  illustrate various aspects of embodiments of such a fabric dyeing apparatus and/or method. 
     Some embodiments of the fabric dyeing apparatus  10  can include a plurality of discrete chambers ( 11 - 25 ) for processing fabric through different steps in a process for dyeing fabric.  FIG. 1  shows a diagrammatic embodiment of the fabric dyeing apparatus  10  having 15 chambers. 
     In an exemplary embodiment of a fabric dyeing apparatus  10 , the apparatus  10  can include a tunnel comprising a plurality of chambers ( 11 - 25 ) through which a load of fabric is successively transferred. A first set of the plurality of chambers ( 11 - 25 ) can comprise a consecutive series of dye chambers  30  (chambers  11 - 16 , as shown in  FIG. 3 ) or dye chambers  31  (chambers  12 - 18 , as shown in  FIG. 2 ) through which the fabric load and a single dye bath are successively transferred, in which the dye bath is heated to about the same temperature in each of the dye chambers  30 ,  31 , and in which the fabric load is exposed to the dye bath for about 35 minutes to about 60 minutes. The first chamber  11  or  12  in the series of dye chambers  30  or  31 , respectively, and each chamber ( 17 - 25 , as shown in  FIG. 3 , or  19 - 25 , as shown in  FIG. 2 ) subsequent to the dye chambers  30 ,  31  can be adapted to receive a fresh water bath. A last chamber  16  or  18  in the series of dye chambers  30  or  31 , respectively, and each subsequent chamber ( 17 - 25  or  19 - 25 ) can be adapted to drain the bath in those chambers ( 17 - 25  or  19 - 25 ). 
     In some embodiments, the tunnel comprising the fabric dyeing apparatus  10  can be a modified bleaching tunnel. Some embodiments of the fabric dyeing apparatus  10  can include 15 chambers, for example, an embodiment that is converted from a conventional 15-chamber bleaching tunnel. That is, a fabric bleaching tunnel comprising a plurality of chambers  11 - 25  can be converted into a dyeing apparatus capable of dyeing fabric. For example, a bleaching tunnel in which a load of fabric can be successively transferred through the plurality of chambers  11 - 25  can be modified to receive a dye bath in a first set of selected chambers  30 ,  31 , and to drain the bath in a second set of selected chambers  17 - 25  or  19 - 25 , respectively. 
     A conventional fabric bleaching tunnel that can be converted, or adapted, for use as an embodiment of the fabric dyeing apparatus  10  is the Power Trans PT 50-15 Beaching Tunnel commercially available from Kannegiesser-USA located in Grand Prarie, Tex. A bleaching tunnel comprising a high quality stainless steel, such as at least a 316 gauge stainless steel, is preferable for conversion to the fabric dyeing apparatus  10  because such higher grade stainless steel can better withstand the corrosive effect of salt utilized in certain chambers in some fabric dyeing processes. 
     One cost savings realized by the fabric dyeing apparatus  10  and/or methods relates to the reuse of the same heated dye bath in the set of dye chambers  30  (chambers  11 - 16 , as shown in  FIG. 3 ) or dye chambers  31  (chambers  12 - 18 , as shown in  FIG. 2 ). Since each of the set of dye chambers  30 ,  31  is heated to the same temperature, and the load of fabric or fabric product and the same dye bath are transferred through each of the set of dye chambers  30 ,  31 , the amount of energy required to heat each chamber after the initial chamber in the dye chambers  30 ,  31  is reduced. In addition, due to the use of preheated fabric or fabric product and dye bath in each chamber after the initial chamber in the dye chambers  30 ,  31 , the amount of time needed to heat those chambers to the desired temperature after the load and dye bath are added is also reduced. 
     In some embodiments, a fresh water bath can be introduced in each of the chambers ( 19 - 25 ) following the initial dye chambers  30  comprising the dye bath, as in  FIG. 2 . In other embodiments, a fresh water bath can be introduced in each of the chambers ( 17 - 25 ) following the initial dye chambers  31  comprising the dye bath, as in  FIG. 3 . A fresh water bath provides a rinse for the fabric or fabric product to remove excess dye, acid, after scour, softener, or other bath mixture ingredients, depending on the chamber in which the water rinse is introduced. 
     In some embodiments of the fabric dyeing apparatus  10  (modified from a conventional bleaching tunnel), one or more of the chambers ( 11 - 25 ) can be configured as circular drums and can rotate about a central axis  60 . In certain embodiments, one or more of the chambers ( 11 - 25 ) can rotate in complete revolutions, or spin, about the central axis  60  so as to tumble or agitate the load and enhance exposure of the load to the bath in that chamber ( 11 - 25 ). In addition, or alternatively, one or more of the chambers ( 11 - 25 ) can rotate from side to side about the central axis  60  so as to provide agitation. In some embodiments of the fabric dyeing apparatus  10 , each of the chambers ( 11 - 25 ) can rotate about the central axis  60 . 
     Some embodiments of the fabric dyeing apparatus  10  (modified from a conventional bleaching tunnel), can comprise a horizontally disposed drum structure having an open inlet end into which textile goods to be bleached or dyed may be inserted, and an open outlet end through which bleached or dyed textile goods may be discharged. The drum structure can be that of a tunnel type, continuous batch washer. The drum structure can have a stationary cylindrical outer wall  40  and a perforated cylindrical inner chamber  50  concentrically disposed within the outer wall  40 . The inner chamber  50  can be drivable relative to the outer wall  40 , for example, such that the inner chamber  50  is alternately rocked back and forth, or oscillated, through a rotational arc of less than 360 degrees, for example, approximately 240 degrees, and/or rotated through a full 360 degree arc. The interior of the outer wall  40  can be axially divided into a prescour zone positioned at the inlet end and bleach and rinse zones positioned downstream of the prescour zone. Each of the zones can comprise one or more chambers ( 11 - 25 ) in embodiments of the fabric dyeing and/or bleaching apparatus  10 . Likewise, the interior of the inner chamber  50  can be divided into axial sections received within the prescour, bleach, and rinse zones of the outer wall  40 . By rotating at least partially through an arc, the inner chamber  50  can operate to axially shift textile goods through successive sections of the drum structure toward the open outlet end, and then outwardly through the open outlet end. In alternative embodiments, the fabric dyeing apparatus  10  can comprise the horizontally disposed drum structure comprising chambers ( 11 - 25 ) without the outer wall  40 . 
     The fabric dyeing apparatus  10  can further include a drive means for operatively driving the inner chamber  50  relative to the outer wall  40 . The fabric dyeing apparatus  10  can further include a heating means for heating water disposed in the various chambers ( 11 - 25 ) or zones, for example, by injecting steam into the respective chambers ( 11 - 25 ) or zones. The fabric dyeing apparatus  10  can further include a means for selectively adding dyeing process components, bleaching components, and/or other bath components to the various chambers ( 11 - 25 ) or zones. The fabric dyeing apparatus  10  can further include circulation means for providing water in the various chambers ( 11 - 25 ) or zones in a manner so as to maintain essentially constant, equal heights of water in lower side portions of each of the chambers ( 11 - 25 ) or zones and in the sections of the inner chamber  50  disposed therein. 
     Thus, in some embodiments of the fabric dyeing apparatus  10 , such a tunnel can comprise a horizontally disposed drum structure, in which the plurality of chambers ( 11 - 25 ) is disposed along the central axis  60  between an inlet end into which the fabric load can be inserted and an outlet end through which the fabric load can be discharged. Each of the plurality of chambers ( 11 - 25 ) may be movable at least partially about the axis  60  of the drum structure. 
     Embodiments of the fabric dyeing apparatus  10  preferably include 15 chambers, as shown in  FIG. 1 . Alternatively, some embodiments of the fabric dyeing apparatus  10  can include a different number of chambers. For example, some embodiments can include 12 or 13 discrete chambers for processing fabric through different steps in a dyeing process. Such embodiments can be converted from a conventional 12- or 13-chamber bleaching tunnel. In a 12- or 13-chamber fabric dyeing apparatus modified from a bleaching tunnel, the same sequence of baths can be provided as in the 15-chamber fabric dyeing apparatus  10 , and the cycle time(s) can be adjusted to accomplish optimal exposure to each type of bath, such as a dye bath, acid bath, after scour bath, and softener bath for a reactive dyeing process, or a dye bath, fixing agent bath, and softener bath for a direct fabric dyeing process. 
     In another alternative embodiment, the fabric dyeing apparatus  10  can include as few as four chambers useful for a reactive fabric dyeing process. In such a four-chamber apparatus, the first chamber can comprise a dye and alkali bath, the second chamber an acid rinse, the third chamber an “after scour” rinse, and the fourth chamber a softener rinse. In yet another alternative embodiment, the fabric dyeing apparatus  10  can include as few as three chambers useful for a direct fabric dyeing process. In such a three-chamber apparatus, the first chamber can comprise a dye and salt bath, the second chamber a bath having a fixing agent, and the third chamber a softener rinse. 
     In some embodiments, a conventional bleaching tunnel as described herein can be modified so as to accommodate both bleaching and dyeing a load of fabric or fabric product. For example, such a bleaching tunnel can be adapted to bleach the fabric load in one cycle through the plurality of chambers ( 11 - 25 ) and/or dye the fabric load in another cycle through the plurality of chambers ( 11 - 25 ). 
     Such a conventional bleaching tunnel can include as part of its original design, or it can be modified to include, components of an embodiment of the fabric dyeing apparatus  10  as desired. For example, a conventional bleaching tunnel can include as part of its original design, or it can be modified to include, a drain mechanism in particular chambers, such as the eighth through fifteenth chambers ( 18 - 25 , as shown in  FIG. 2 ) or the sixth through eleventh and fifteenth chambers ( 16 - 21  and  25 , as shown in  FIG. 3 ), so as to allow draining those chambers as desired in a fabric dyeing process. In addition, or alternatively, such a conventional bleaching tunnel can be modified to include in selected chambers other components of an embodiment of the fabric dyeing apparatus  10  that are not included in the original design of the bleaching tunnel, such water inlet valve(s) and/or one or more inlet ports for dye, salt, wetter, lubricant, acid, after scour, softener, and/or other bath ingredients. In this way, the modified bleaching tunnel can comprise an embodiment of the fabric dyeing apparatus  10  and be utilized for both bleaching and for dyeing fabric and/or fabric products. 
     As an example of a bleaching tunnel than can be utilized for both bleaching and for dyeing a load of fabric or fabric product, the apparatus  10  can be configured for bleaching as follows: chambers  11  and  12  for scouring fabric; chamber  13  for draining and then adding bleaching chemicals; chambers  13 - 19  for bleaching; chamber  20  for draining; chambers  21 - 24  for rinsing; and chamber  25  for adding a softener. The same apparatus  10  can be configured for dyeing a load of fabric or fabric product as follows: chambers  11 - 12  for adding a dye bath; chamber  13  for adding alkali; chambers  14 - 18  for transferring the load and dye bath from chamber  13  through each of these chambers  14 - 18 ; chamber  18  for draining the bath; chamber  19  for a water rinse and draining; chamber  20  for a water rinse with acid and draining; chamber  21  for a water rinse and draining; chamber  22  for adding a water and after scour rinse and draining; chambers  23 - 24  for adding a water rinse and draining; and chambers  25  for adding a water rinse and softener and draining. In such an example of a modified bleaching tunnel, fabric or fabric product can be bleached in one cycle through the 15 chambers ( 11 - 25 ) of the apparatus  10  and dyed through a different cycle through the 15 chambers ( 11 - 25 ). 
     In a conventional fabric dyeing process, about one part fabric or fabric product is typically placed in about 10 parts of a dye bath mixture, for a weight ratio of dye bath mixture-to-fabric or fabric product of about 10:1. In some embodiments of the fabric dyeing apparatus  10  and/or methods of the present invention, about one part fabric or fabric product can be effectively processed in about five parts of a dye bath mixture, for a weight ratio of dye bath mixture-to-fabric or fabric product of about 5:1. As an example, for a load comprising approximately 100 lbs. of fabric or fabric product in the chambers ( 11 - 25 ) in the fabric dyeing apparatus  10 , about 500 lbs. of water and dye bath mixture components can be utilized in the dye bath. Accordingly, the ratio of dye bath mixture-to-fabric or fabric product in some embodiments of the present invention can be substantially less than the ratio of dye bath mixture-to-fabric or fabric product in a conventional fabric dyeing process. Thus, about twice as much fabric or fabric product can be dyed in embodiments of the present invention in the same amount of water as can be dyed in conventional dyeing processes. As a result, some embodiments of the fabric dyeing apparatus  10  and/or methods can provide a cost savings compared to a conventional fabric dyeing process. 
     Embodiments of the fabric dyeing apparatus  10  can be utilized to effectively dye a fabric comprising cotton or a cotton blend. However, the fabric dyeing apparatus  10  can be utilized to dye fabric comprising other natural or synthetic fibers or combinations thereof. 
     The present invention includes embodiments of a method for dyeing fabric. One such embodiment includes modifying a fabric bleaching tunnel comprising the plurality of chambers ( 11 - 25 ) to receive a dye bath in a first set of selected chambers  30 ,  31  and to drain the bath in a second set of selected chambers (of chambers  11 - 25 ) such that a load of fabric can be successively transferred through the plurality of chambers ( 11 - 25 ). In this way, the bleaching tunnel is capable of dyeing fabric. In a bleaching tunnel modified as such, a fabric load can be bleached in one cycle through the plurality of chambers ( 11 - 25 ), and the fabric load can be dyed in another cycle through the plurality of chambers ( 11 - 25 ). 
     In some embodiments, such a method can further include transferring the fabric load into the dye bath at a weight ratio of the dye bath-to-fabric of about a 5:1, as described herein in relation to the fabric dyeing apparatus  10 . 
     Fabric and fabric products can be dyed in various ways, including “reactive dyeing” and “direct dyeing.” Accordingly, in some embodiments of the present invention, fabric can be dyed with a fiber reactive dye. In other embodiments, fabric can be dyed with a direct fiber dye. 
     Fiber reactive dyes are often used to dye cotton, cellulose, and blends thereof. These dyes can also be used to dye acrylics, nylon, silk, and wool, and blends of these fibers. Fiber reactive dyes are easy to apply and produce brilliant shades, fastness, penetration, and leveling. Fiber reactive dyes are anionic in nature and react chemically with the fiber. The dyes include a chromophore to give color to the dye and a reactive group to form a chemical bond with the fiber. There may also be a substitutent or solubilizing group which provides additional dyeing characteristics such as solubility, substantivity, migration, washing off, etc. Fiber reactive dyes react in the presence of alkali to form a strong covalent chemical bond between a carbon atom of the dye molecule and an oxygen atom of the hydroxyl group in the cellulose. In this way, reactive dyeing can produce a high level of color fastness in the dyed fabric. 
     “Direct dyeing” involves attraction of dye to fabric fibers, such as cotton, by van der Waals forces, which includes electrostatic, polar, and other forces of attraction between molecules. As such, direct dyeing can be less predictable than reactive dyeing due to, for example, possible inconsistencies in dye attraction to the fabric, which may not be visualized until the dyeing process is completed. However, in conventional fabric dyeing processes, due to the length of processing time required, and possibly due to the amount of dye utilized, reactive dyeing may be more expensive than direct dyeing. Thus, in order to control cost, direct dyeing is often utilized in such conventional fabric dyeing processes, for example, with products in which color fastness may not be a top priority. 
     In addition, although reactive dyeing may provide certain advantages, some conventional dyeing processes for fabric can require six or more hours of processing time. In contrast, fabric or fabric products can be fully processed in the fabric dyeing apparatus  10  and/or methods of the present invention in about two (2) hours. For example, a load of about 105 lbs. of fabric or fabric products can be cycled through one of the 15 chambers of the apparatus  10  about every eight (8) minutes, as illustrated in  FIGS. 2 and 3 . A new 105 lb. load of fabric or fabric products can be loaded into the first chamber  11  every eight minutes (following transfer of the existing load from the first chamber  11  to the second chamber  12 ). That is, the first 105 lb. batch, or load, of fabric or fabric products can be dyed in about two hours, followed by another load about every eight minutes. As a result, in about six hours, 42 loads (about 4,410 lbs.) of fabric or fabric products can be dyed utilizing the fabric dyeing apparatus  10  and/or methods of the present invention. In contrast, only about 350 lbs. of fabric or fabric products can be processed in a conventional dyeing process in the same amount of time. Thus, some embodiments of the present invention can provide an increased volume of dyed fabric and/or fabric products in a substantially reduced processing time, as compared to conventional dyeing processes. Accordingly, dyeing fabric in some embodiments of the fabric dyeing apparatus  10  and/or methods of the present invention can significantly reduce the cost of dyeing fabric in conventional dyeing apparatus and utilizing conventional methods. 
     Whether a reactive dye or a direct dye, the dye is a colorant that adheres to a fabric substrate during application and exhibits some degree of permanence on the fabric. Dyes can be either natural or synthetic. 
     As described above, in some embodiments, a method of dyeing fabric can comprise utilizing a fiber reactive dye.  FIG. 2  provides a chart identifying the additives, temperature, and cycle time in each of the chambers ( 11 - 25 ) of the fabric dyeing apparatus  10  for dyeing fabric in an embodiment of a reactive fabric dyeing process. 
     In some embodiments of a reactive dyeing method utilizing the 15-chamber fabric dyeing apparatus  10 , the first eight chambers ( 11 - 18 ) can be utilized for creating the dye bath, adding an alkali, and holding the fabric load in exposure to the dye bath for a desired period of time, for example, for about 56 minutes, as described above with respect to the first eight chambers ( 11 - 18 ) in  FIGS. 1 and 2 . As shown in the embodiment in  FIG. 1 , the first through eighth chambers ( 11 - 18 , respectively) through which the fabric load and dye bath are successively transferred can be referred to collectively as dye chambers  31 . 
     In particular embodiments, an alkali can be added to raise the pH of the dye bath to within a range of about 11.0 to about 11.5. In some embodiments, one of the chambers ( 16 - 25 ) subsequent to the dye chambers  30  can comprises an acid rinse. An acid, such as acetic acid, can be added to neutralize the alkaline environment in the fabric dyeing process created by the previously added alkali. Preferably, a sufficient amount and concentration of acid can be added to bring the surface of the fabric to a pH of about 7.0. One of the chambers subsequent to the chamber comprising the acid rinse can comprise an after scour rinse for the purpose of removing excess dye from the fabric after the dye has been chemically reacted with the fabric. And, one of the chambers subsequent to the chamber comprising the after scour rinse comprises a softener rinse. 
     For example, in an embodiment of a reactive fabric dyeing process, as illustrated in  FIG. 2 , the method can include adding the fabric load to a dye bath in a first chamber  11  comprising water, salt, lubricant, and wetting agent. The salt can be any salt useable in commercial fabric dyeing processes, for example, sodium chloride (NaCl) or sodium sulfate (Na 2 SO 4 ). The lubricant can be an oil or oil emulsion that decreases rubbing of the surfaces of the fabric or fabric products against each other and thus avoid pilling of the fabric during processing. The wetting agent, or wetter, can be a surfactant that is effective in promoting wetting of a textile by lowering the surface tension of a liquid, such as water, so as to increase its spreading and penetrating properties. Use of a wetting agent can facilitate absorption of the dye by the fabric. 
     The fabric load and dye bath are transferred from the first chamber  11  to a second chamber  12  and a reactive dye is added. The fabric load and dye bath are next transferred to a third chamber  13  and an alkali is added. The fabric load and dye bath are then successively transferred to a fourth through eighth chambers  14 - 18 , respectively, and heated to within the same temperature range in each of the fourth through eighth chambers  14 - 18 , respectively. From the eighth chamber  18 , the fabric load is transferred to a subsequent chamber including a water and acid rinse. Finally, the fabric load is transferred to a water and after scour rinse in a chamber subsequent to the chamber having the water and acid rinse. 
     As shown in the particular embodiment of a fiber reactive dyeing process in  FIG. 2 , a fabric load can be added to a dye bath in the first chamber  11  comprising water, salt, lubricant, and wetting agent, and heated to between about 90 and about 110 degrees F., preferably about 100 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the first chamber  11  to the second chamber  12 , a dye added to the bath, and heated to between about 90 and about 110 degrees F., preferably about 100 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the second chamber  12  to the third chamber  13 , an alkali added to raise the pH of the dye bath to within a range of about 11.0 to about 11.5, and heated to between about 90 and about 110 degrees F., preferably about 100 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the third chamber  13  to the fourth chamber  14 , and heated to between about 120 and about 180 degrees F., preferably between about 135 and about 145 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the fourth chamber  14  to the fifth chamber  15 , and heated to between about 120 and about 180 degrees F., preferably between about 135 and about 145 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the fifth chamber  15  to the sixth chamber  16 , and heated to between about 120 and about 180 degrees F., preferably between about 135 and about 145 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the sixth chamber  16  to the seventh chamber  17 , and heated to between about 120 and about 180 degrees F., preferably between about 135 and about 145 degrees F., for about eight minutes. The fabric load and dye bath can be transferred from the seventh chamber  17  to the eighth chamber  18 , heated to between about 120 and about 180 degrees F., preferably between about 135 and about 145 degrees F., for about eight minutes, and the dye bath drained. 
     The fabric load can then be transferred from the eighth chamber  18  to the ninth chamber  19  into a water rinse having a temperature in the range of about 60 degrees F. to about 100 degrees F. for about eight minutes, and the water rinse drained. The fabric load can then be transferred from the ninth chamber  19  to the tenth chamber  20  into a water and acid rinse to bring the surface of the fabric to a pH of about 7.0, heated to between about 130 degrees F. and about 150 degrees F., preferably about 140 degrees F., for about eight minutes, and the water and acid rinse drained. The fabric load can then be transferred from the tenth chamber  20  to the eleventh chamber  21  into a water rinse, heated to between about 130 degrees F. and about 150 degrees F., preferably about 140 degrees F., for about eight minutes, and the water rinse drained. The fabric load can then be transferred from the eleventh chamber  21  to the twelfth chamber  22  into a water and after scour rinse, heated to between about 180 degrees F. about 200 degrees F., preferably about 190 degrees F., for about eight minutes, and the water and after scour rinse drained. The fabric load can then be transferred from the twelfth chamber  22  to the thirteenth chamber  23  into a water rinse, heating to between about 130 degrees F. and about 150 degrees F., preferably about 140 degrees F., for about eight minutes, and the water rinse drained. The fabric load can then be transferred from the thirteenth chamber  23  to the fourteenth chamber  24  into a water rinse, heated to between about 130 degrees F. and about 150 degrees F., preferably about 140 degrees F., for about eight minutes, and the water rinse drained. The fabric load can then be transferred from the fourteenth chamber  24  to the fifteenth chamber  25  into a water and softener rinse, heated to between about 110 degrees F. and about 120 degrees F. for about eight minutes, and the water rinse drained. Accordingly, the method of dyeing fabric or fabric product illustrated in  FIG. 2  can be accomplished in the 15-chamber fabric dyeing apparatus  10  illustrated in  FIG. 1 , to provide a load of dyed fabric or fabric product in a cost-effective manner. In such a method, the fabric load can be processed through the fabric dyeing apparatus  10  in about two hours. 
     Examples of the additives to water in such a fiber reactive dyeing process are provided in Table 1 below: 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Additive 
                 Commercial Example 
                 Amount 
               
               
                   
               
             
            
               
                 Salt 
                 Sodium Sulfate or Sodium 
                 100 grams/liter of water 
               
               
                   
                 Chloride 
               
               
                 Lubricant 
                 Surlube CAR 
                 1.00% 
               
               
                 Wetting Agent 
                 Surchem Jet 
                 1.00% 
               
               
                 Dye 
                 Permabril Orange BF-2R 
                 0.44% 
               
               
                 Dye 
                 Permabril Red BF-RX 
                 0.11% 
               
               
                 Dye 
                 Permabril Black DTM 
                 4.62% 
               
               
                 Alkali 
                 Surchem E.F.A. Plus 
                 4.00% (liquid) 
               
               
                 Acid 
                 Acetic Acid 
                 1.00% 
               
               
                 Softener 
                 Sursoft HB-NA 
                 1.50% 
               
               
                   
               
            
           
         
       
     
     These additives are commercially available from Surry Chemicals, Inc., in Mount Airy, N.C. Surlube CAR is both a fiber-to-fiber and a fiber-to-metal lubricant. Surchem Jet is an anionic/non-ionic wetter. The amount of each dye to be added depends on the amount of cotton in the fabric being dyed. The Permabril dyes are vinyl sulfone class dyes; the dye baths including this class of dyes should be heated to the temperature ranges shown in  FIG. 2 . If other classes of dyes are utilized, the temperatures to which the dye baths are heated can vary. Sursoft HB-NA is a cationic hydrophilic softener. 
     As described above, in some embodiments, a method of dyeing fabric can comprise utilizing a direct fiber dye.  FIG. 3  provides a chart identifying the additives, temperature, and cycle time in each of the chambers of the fabric dyeing apparatus  10  shown in  FIG. 1 , for dyeing fabric in an embodiment of a direct fabric dyeing process of the present invention. 
     In some embodiments of a direct dyeing method utilizing the 15-chamber fabric dyeing apparatus  10 , the first six chambers ( 11 - 16 ) can be utilized for creating the dye bath, adding a salt, and holding the fabric load in exposure to the dye bath for a desired period of time, for example, for about 48 minutes, as described above with respect to the first six chambers ( 11 - 16 ) in  FIGS. 1 and 3 . As shown in the embodiment in  FIG. 1 , the first through sixth chambers ( 11 - 16 , respectively) through which the fabric load and dye bath are successively transferred can be referred to collectively as dye chambers  30 . 
     As shown in the embodiment of a direct dyeing process in  FIG. 3 , a fabric load can be added to a dye bath in the first chamber  11  comprising water, dye, lubricant, and wetting agent. The fabric load and dye bath can be transferred to the second chamber  12  and a salt added. The fabric load and dye bath can then be successively transferred through the third through sixth chambers  13 - 16 , respectively, and heated to within a first temperature range in each of the third through sixth chambers  13 - 16 , respectively. The fabric load can then be transferred to each of the seventh through tenth chambers  17 - 20 , respectively, each of the seventh through tenth chambers  17 - 20 , respectively, having a separate water and salt rinse in a second temperature range lower than the first temperature range. The fabric load can then be transferred into the eleventh chamber  21  comprising a water bath having a cellulosic fixing agent. The fabric load and water bath can then be transferred to each of the twelfth through fourteenth chambers  22 - 24 , respectively, and heated to within a third temperature range between the first and second temperature ranges in each of the twelfth through fourteenth chambers  22 - 24 , respectively. And, then the fabric load can be transferred into the fifteenth chamber  25  into a water and softener rinse. 
     In a particular embodiment of such a direct dyeing process, the fabric load can be added to a dye bath in the first chamber  11  comprising water, dye, lubricant, and wetting agent, and held a temperature between about 60 degrees F. and about 100 degrees F., preferably about 100 degrees F., for about eight minutes. The fabric load and dye bath can then be transferred from the first chamber  11  to the second chamber  12 , salt added, and the temperature of the bath controlled to between about 60 degrees F. and about 100 degrees F., preferably about 140 degrees F., for about eight minutes. The fabric load and dye bath can then be transferred from the second chamber  12  to the third chamber  13 , then to the fourth chamber  14 , and then to the fifth chamber  15 , and the bath heated in each of the third, fourth, and fifth chambers  13 ,  14 ,  15 , respectively, to between about 200 degrees F. and about 210 degrees F. for about eight minutes. The fabric load and dye bath can then be transferred from the fifth chamber  15  to the sixth chamber  16 , heated to between about 200 degrees F. and about 210 degrees F. for about eight minutes, and the dye bath drained. 
     The fabric load can then be transferred from the sixth chamber  16  to the seventh chamber  17  into a water and salt rinse having a temperature between about 60 degrees F. and about 100 degrees F. for about eight minutes, and the rinse drained. The fabric load can then be transferred from the seventh chamber  17  to the eighth chamber  18  into a water and salt rinse having a temperature between about 60 degrees F. and about 100 degrees F. for about eight minutes, and the rinse drained. The fabric load can then be transferred from the eighth chamber  18  to the ninth chamber  19  into a water and salt rinse having a temperature between about 60 degrees F. and about 100 degrees F. for about eight minutes, and the rinse drained. The fabric load can then be transferred from the ninth chamber  19  to the tenth chamber  20  into a water and salt rinse having a temperature between about 60 degrees F. and about 100 degrees F. for about eight minutes, and the rinse drained. The fabric load can then be transferred from the tenth chamber  20  to the eleventh chamber  21  comprising a water bath having a cellulosic fixing agent and a temperature between about 60 degrees F. and about 100 degrees F. for about eight minutes. The fabric load and water bath can then be transferred from the eleventh chamber  21  to the twelfth chamber  22  and heated to between about 120 degrees F. and about 180 degrees F. for about eight minutes. The fabric load and water bath can then be transferred from the twelfth chamber  22  to the thirteenth chamber  23  and heated to between about 120 degrees F. and about 180 degrees F. for about eight minutes. The fabric load and water bath can then be transferred from the thirteenth chamber  23  to the fourteenth chamber  24 , heated to between about 120 degrees F. and about 180 degrees F. for about eight minutes, and the water bath drained. The fabric load can then be transferred from the fourteenth chamber  24  to the fifteenth chamber  25  into a water and a softener rinse having a temperature between about 110 degrees F. and about 120 degrees F. for about eight minutes, and the rinse drained. Accordingly, the method of dyeing fabric or fabric product illustrated in  FIG. 3  can be accomplished in the 15-chamber fabric dyeing apparatus  10  illustrated in  FIG. 1 , to provide a load of dyed fabric or fabric product in a cost-effective manner. In such a method, the fabric load can be processed through the fabric dyeing apparatus  10  in about two hours. 
     Examples of the additives to water in such a fiber direct dyeing process are provided in Table 2 below: 
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Additive 
                 Commercial Example 
                 Amount 
               
               
                   
               
             
            
               
                 Dye 
                 Permalite Black SL 
                 2.59% 
               
               
                 Lubricant 
                 Surlube CAR 
                 1.00% 
               
               
                 Wetting Agent 
                 Surchem Jet 
                 1.00% 
               
               
                 Salt in dye bath 
                 Sodium Sulfate or Sodium 
                   40% based on weight 
               
               
                   
                 Chloride 
                 of fabric 
               
               
                 Salt in rinses 
                 Sodium Sulfate or Sodium 
                   3% 
               
               
                   
                 Chloride 
               
               
                 Fixing Agent 
                 Stanfix HB 
                   4% 
               
               
                 Softener 
                 Sursoft HB-NA 
                 1.50% 
               
               
                   
               
            
           
         
       
     
     These additives are commercially available from Surry Chemicals, Inc., in Mount Airy, N.C. The amount of dye to be added depends on the amount of cotton in the fabric being dyed. Surlube CAR is both a fiber-to-fiber and a fiber-to-metal lubricant. Surchem Jet is an anionic/non-ionic wetter. Stanfix HB is a cationic cellulosic fixing agent. Sursoft HB-NA Jet is a cationic hydrophilic softener. 
     Some embodiments of the fabric dyeing apparatus  10  and/or method according to the present invention can provide advantages over conventional approaches to fabric dyeing. For example, compared to a conventional fabric dyeing process, some embodiments of the present invention can operate using at least a decreased amount of water, and possibly a decreased amount of chemicals, in the dye bath mixture, thereby providing a cost savings. 
     Another advantage is that some embodiments of the present invention can provide a substantial reduction in processing time, thereby allowing a cost savings. For example, some embodiments can provide for fully processing a load of fabric or fabric product in about two hours, or about one-third of the time required by conventional reactive dye batch fabric dyeing processes. 
     Another advantage is that some embodiments of the present invention can provide a cost savings by reusing the same heated dye bath in the first set of dye chambers  30 , for example, the first six or eight chambers. As a result of the first set of dye chambers  30 ,  31  being heated to the same temperature, and the load of fabric or fabric product and the same dye bath being transferred through the first set of dye chambers  30 ,  31 , the amount of time and energy required to heat the subsequent chambers in the first set of dye chambers  30 ,  31  to the desired temperature is reduced. 
     Another advantage is that, due to a decreased amount of water and chemical additives in the dye bath mixture compared to some conventional dyeing processes, some embodiments of the present invention can cause less effluent discharge of water and chemicals and thus provide protection to the environment. In addition, reusing the dye bath in certain chambers (for example, chambers  11 - 16  or  11 - 18 ) has the advantages of reducing the amount of water required to provide a fresh bath in each of the chambers ( 11 - 25 ) and of correspondingly reducing the amount of wastewater that must be treated before being discarded into the environment. 
     Another advantage is that transferring the dye bath directly from one chamber to another in certain embodiments of the present invention avoids steps in conventional dye bath recovery and reuse processes, thereby saving the costs involved with those steps. For example, transferring the dye bath directly from one chamber to another can avoid steps such as removing the dye bath from the fabric load, treating the bath, analyzing the bath for levels of dye and associated chemicals, replenishing the dye and associated chemicals to desired levels, and/or returning the refreshed bath to the chamber. 
     Embodiments of the fabric dyeing apparatus and/or method according to the present invention can be utilized in a variety of applications. For example, some embodiments of the apparatus and/or method can be utilized to dye socks. In other embodiments, the fabric dyeing apparatus and/or method can be utilized to dye fabric prior to being constructed into a garment or other fabric product or in fabric products other than socks. 
     Features of a fabric dyeing apparatus and/or method of the present invention may be accomplished singularly, or in combination, in one or more of the embodiments of the present invention. Although particular embodiments have been described, it should be recognized that these embodiments are merely illustrative of the principles of the present invention. Those of ordinary skill in the art will appreciate that a fabric dyeing apparatus and/or method of the present invention may be constructed and implemented in other ways and embodiments. Accordingly, the description herein should not be read as limiting the present invention, as other embodiments also fall within the scope of the present invention.