Patent Application
20240309569
The present invention relates to improvements in or relating to textile dyeing and, in particular, to improving the colourfastness of a dyed textile.
Textile coating or dyeing can be an environmentally damaging process, primarily due to the generation of significant volumes of waste water, typically many times the textile weight.
Conventional processes for dyeing application are bath immersion methods such as exhaustion or jet dyeing, and padding with a roller-application mechanism. Alternatively, coatings or dyestuffs can be applied to the textile via a roller “padding” process. The applied dyestuffs are then dried and heated in order to fixate the dyestuff. For both of these conventional methods of dyeing, washing is required in order to remove excess unbound dyestuffs and auxiliary chemicals. Washing typically involves several baths operated at elevated temperatures and can introduce additional chemicals, for example in the process of “reduction clearing” where a basic pH is used.
Consequently, conventional methods generally overdose the textile material with an excess of dyestuff, which has to be removed via repeated high temperature washes, generating large amounts of contaminated wastewater. Contaminated wastewater, including water contaminated with dyestuffs, is a considerable worldwide environmental issue and necessitates extensive waste water treatment to avoid environmental damage.
It is against this background that the present invention has arisen.
According to the present invention, there is provided a method for improving the colourfastness of a dyed textile, the method comprising conveying a dyed textile along a processing line in a first direction; flowing a fluid from a reservoir through the dyed textile on the processing line in a second direction substantially opposite to the first direction; subsequently removing at least 50% of the applied fluid from the dyed textile; removing contaminants from the fluid; and returning the fluid to the reservoir.
The flowing of a fluid through the dyed textile in a direction substantially opposite to the direction in which it is being conveyed allows for the cleanest fluid to be in contact with the cleanest part of the dyed textile. This prevents any contamination of clean parts of the dyed textile with contaminated wastewater. Furthermore, flowing a fluid counter to the direction of movement of the dyed textile may assist in removing excess dyestuffs.
According to the present invention, there is provided a method for improving the colourfastness of a dyed textile, the method comprising conveying a dyed textile along a processing line; applying a fluid to the dyed textile at a first position on the processing line in a second direction substantially opposite to the first direction; and subsequently removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line.
The dyed textile may be continuously conveyed along the processing line. For example, the processing line may be a continuous roll-to-roll processing line. The processing line may be automated. The processing line may comprise a processor configured to control the processing line digitally. The processor may control the speed at which the textile is conveyed along the processing line. In some embodiments, the processing line may be a non-immersive processing line. Traditional dying, washing, and/or fixing processes typically comprise at least one immersion bath. However, a non-immersive processing line is a processing line that does not contain an immersion bath.
In some embodiments, the dyed textile may be in a consolidated form. For example, the dyed textile may be being conveyed as a roll. Alternatively, the dyed textile may be in an unconsolidated form. For example, the dyed textile may be being conveyed in a linear form.
The dyed textile may be at an elevated temperature. For example, the dyed textile may be between 10° C.-220° C., 15° C.-200° C., 20° C.-180° C., 25° C.-140° C. or 30° C.-100° C. The temperature of the dyed textile and/or processing line may be controlled. This may improve the handfeel of the dyed textile.
The first and second position on the processing line may be substantially the same position. For example, the first and second position on the processing line may overlap. Alternatively, or in addition, the first and second position on the processing line may be adjacent to one another. Conversely, in some embodiments, the first and second positions may be distinct from each other.
For example, the first and second position may be within 1 meter of each other. Alternatively, the first and second position may be within 0.75m, 0.5m, 0.25m or 0.1m of each other. For example, the first and second position on the processing line may be opposite each other, adjacent to each other and/or on top of each other.
The fluid may comprise a liquid. More specifically, the fluid may be a liquid. For example, the fluid may be water. However, any suitable liquid may be used. The fluid may comprise a fragrance. Alternatively, or in addition, the fluid may comprise a gas. The gas may be air. However, any suitable gas may be used. The gas may comprise a solid. For example, the fluid may comprise air and sand/grit configured to sandblast the dyed textile.
Removing the fluid from the dyed textile may be in the form of a de-watering step. Physically removing the fluid from the textile also removes any remaining dyestuff and/or chemistry that has not fixated to the textile. Conversely, drying the textile leaves un-fixed dyestuff and/or chemistry on the textile.
Removing the applied fluid enables the fluid to be reused, which reduces the total amount of fluid required. In some embodiments, at least 60%, 70%, 80%, 90%, 95% or 99% of the applied fluid may be removed from the dyed textile. Preferably, at least 75% of the applied fluid is removed from the dyed textile at the second position on the processing line.
The fluid removal rate may be greater than 0.5, 1, 1.5, 2, 2.5 or 3 times the mass flow rate of the dyed textile. Alternatively, or in addition, the mass of fluid retained in the textile downstream of the second position of the processing line may be less than 0.5, 0.3, 0.2, 0.1 or 0.05 the mass flow rate of the textile.
In this context, the mass flow rate may be defined as the mass of the dyed textile that passes a given point per unit of time. For example, the mass flow rate may be defined as the mass of the dyed textile that passes the first position on the processing line per unit of time.
The fluid may be removed from the textile by a vacuum. A vacuum may efficiently remove the fluid without damaging the textile. Alternatively, or in addition, fluid may be removed from the textile by applying a high velocity gas to the textile. The gas may be air. The high velocity gas may pass through the textile. The high velocity gas may be configured to remove excess liquids and unfixed solids from the dyed textile.
The fluid applied to the dyed textile at the first position on the processing line may be a predetermined volume of fluid. More specifically, the fluid applied to the dyed textile at the first position on the processing line may comprise a predetermined volume of liquid.
Accordingly, the method may comprise a step of applying a predetermined volume of fluid to the dyed textile at a first position on the processing line. For example, fluid may be applied to the dyed textile until the textile reaches a predetermined water content. The application of the fluid to the dyed textile may be controlled. Moreover, the application of the fluid to the dyed textile may be adjusted.
Alternatively, or in addition, the fluid applied to the dyed textile at the first position on the processing line may be applied at a predetermined rate.
The method may further comprise removing contaminants from the removed fluid; and re-applying the fluid to the dyed textile. More specifically, the method may comprise re-applying the fluid to the dyed textile at the first position on the processing line. Alternatively, or in addition, the method may comprise re-applying the fluid to the dyed textile at a third position on the processing line. The third position may be upstream of the second position.
A fluid may be initially applied to and subsequently removed from the first location of the dyed textile. The fluid may then be decontaminated and re-applied to a second location of the dyed textile. The re-applied fluid may be subsequently removed from the second location of the dyed textile at the second position on the processing line.
The method may further comprise applying a fluid to the dyed textile at a third position on the processing line; and subsequently removing at least 50% of the fluid applied at the third position from the dyed textile at a fourth position on the processing line.
Accordingly, the method of claim 1 may be repeated. More specifically, the method may be repeated a plurality of times. For example, the method may be repeated 1, 2, 3, 4, 5, 8, 10 or more than 10 times.
The fluid being re-applied may be re-applied at the first and/or third position on the processing line. The fluid may be applied to, removed from and re-applied to the textile at any number of locations on the dyed textile. For example, the fluid may be applied to, removed from and re-applied to the textile at 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 locations on the dyed textile.
The method may be continuous. For example, the method may comprise continuously conveying a dyed textile along a processing line; continuously applying a fluid to the dyed textile at a first position on the processing line; and subsequently, continuously removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line.
The method may further comprise continuously removing contaminates from the removed fluid. Moreover, the method may comprise continuously re-applying the removed fluid to the dyed textile.
More specifically, the method may comprise continuously re-applying the removed fluid to the dyed textile at the first position on the processing line. Alternatively, or in addition, the method may comprise continuously re-applying the removed fluid to the dyed textile at a third position on the processing line. This looped method further reduces the amount of water used.
The total mass of fluid applied to the dyed textile may be up to 500% of the mass of the dyed textile. More specifically, in some embodiments, the total mass of fluid applied to the dyed textile may be up to 75%, 100%, 150%, 200%, 250% or 300% of the mass of the dyed textile. Alternatively, or in addition, the total mass of fluid applied to the dyed textile may be 50%-350%, 100%-300% or 150%-250% of the mass of the dyed textile. The fluid application rate may be greater than 0.5, 1, 1.5, 2, 2.5 or 3 times the mass flow rate of the dyed textile. However, in some embodiments, the total mass of fluid applied to the dyed textile may be less than 50%, 30%, 20%, 10% or 5% of the mass of the dyed textile.
The fluid applied to the dyed textile at the first position may be applied at 1-50 litres per minute. Alternatively, the fluid may be applied at 1-20 litres per minutes (l/min). The textile may be conveyed at 1-100 meters per minute (m/min). More specifically, the textile may be conveyed at 5-50 m/min or 10-20m/min.
In some embodiments, less fluid may be removed from the dyed textile at the second position than is 15 applied to the dyed textile at the first position. Removing less fluid than is applied may be desirable in order to leave predefined chemistry within the fluid on the textile, for example.
The method may further comprise heating the fluid to above 40° C. More specifically, the fluid may be heated to above 50° C., 60° C. or 70° C. Alternatively, or in addition, the fluid may be heated to 40° C. -80° C., 50° C.-70° C. or to approximately 60° C. For example, the temperature of the fluid may be adjusted to optimise the cost of the method and the total energy used during the method.
The method may further comprise heating the first position on the processing line to 40-95° C. More specifically, the method may comprise heating the first position on the processing line to 50-70° C. or approximately 60° C. Increasing the temperature of the environment of the first position reduces the cooling effect of the fluid application, thus reducing the total energy required by the method. In some embodiments, excess heat from the fixation chamber may be used to heat the first position.
The method may further comprise determining a range of acceptable flow rates for the fluid being applied; monitoring the flow rate of the fluid being applied; and adjusting the flow rate of the fluid being applied if the flow rate of fluid being applied is outside of the range of acceptable flow rates.
Consequently, the fluid being applied can be accurately monitored and adjusted, in use. This can be used to optimise the method, thus increasing the efficiency of the method.
The fluid may be sprayed onto the dyed textile. The fluid may be sprayed onto the dyed textile via a plurality of spray nozzles. This may ensure that the entirety of the textile is sprayed. Moreover, spraying the fluid may agitate the textile, thus removing some of the excess and/or unfixed dyestuff therefrom. This may improve the colourfastness of the dyed textile. Moreover, spraying the fluid onto the dyed textile enables significantly less water to be used compared to more traditional methods. This is particularly advantageous in terms of cost and environmental impact. The fluid may be sprayed onto the textile at a velocity of at least 10 m/s, at least 15 m/s or, most preferably, at least 20 m/s.
However, in some embodiments, the fluid may be applied to the textile via slot die liquid application or dip application. Alternatively, or in addition, the fluid may be applied to the textile via rotary printing application, such as a rotary screw or gravure sprinkler. Moreover, in some embodiments, the fluid may be applied to the textile via a waterfall, weir, sprinkler or jet.
The method may further comprise mechanically agitating the dyed textile. Mechanically agitating the dyed textile may remove some of the excess dye, thus improving the colourfastness of the dyed textile. More specifically, the mechanical agitation may be configured to move textile fibres, thus exposing the excess, unfixed dye.
The mechanical agitation may apply pressure to the dyed textile. The mechanical agitation may effectively squeeze fluid out of the textile. The mechanical agitation may be configured to reduce the mass of water within the textile to less than the mass flow rate of the textile.
For example, the mechanical agitation may comprise a pair of rollers configured to contact the textile being conveyed along the processing line. More specifically, the mechanical agitation may comprise a pair of nip rollers. The pair of nip rollers may reduce the mass of water within the dyed textile to less than 60% of the mass flow rate of the dyed textile
The mechanical agitation may occur between the first and second position on the processing line. Alternatively, or in addition, the mechanical agitation occurs at the first and/or second position on the processing line. For example, the application of fluid can also be combined by mechanical agitation via rollers in contact with the textile.
Moreover, in some embodiments, mechanical agitation may occur between the third and fourth position on the processing line.
Alternatively, or in addition, the applied fluid may be configured to agitate the textile. For example, fluid may be forced through the textile at the first position on the processing line. In such an embodiment, the fluid removal may occur opposite the fluid applicator. The second position on the processing line may be directly opposite the first position on the fluid processing line.
The fluid may comprise an additive configured to improve the colourfastness of the textile. In some embodiments, the fluid comprises a plurality of additives configured to improve the colourfastness of the textile. For example, the additive may be a finishing chemistry. The additive may be configured to allow movement of the textile fibres without resulting in dyestuff being removed from the textile.
Alternatively, or in addition, the additive may comprise an anionic or cationic surfactant. Alternatively, the additive may comprise any detergent species. In some embodiments, the additive may comprise a polymer species. The polymer species may comprise an aliphatic or silicon-based backbone.
Alternatively, or in addition, the fluid may comprise a lubricating and/or softening additive. The fluid may comprises an additive configured to improve the softness of the textile. The additive may be a chemical softener. The chemical may be a silicone. The softener may be a biological extract. Alternatively, or in addition, the fluid may comprise a colourless dispersant. Moreover, the fluid may be water-based and/or may be mixed with fresh water, in use.
Alternatively, or in addition, there is also provided a method for improving the colourfastness of a dyed textile, the method comprising conveying the dyed textile along a processing line and into a first chamber having a first controllable environment; temporarily storing the dyed textile in the first chamber for a first time period; conveying the dyed textile into a second chamber having a second controllable environment; and temporarily storing the dyed textile in the second chamber for a second time period. The processing line may be automated. The processing line may be the same processing line as previously disclosed.
The first controllable environment may be different to the second controllable environment. Alternatively, the first and second controllable environments may be the same. More specifically, the first controllable environment may comprise a plurality of parameters. For example, the first controllable environment may comprise a first temperature, humidity, pressure, airflow velocity, and/or inert gas. Alternatively, or in addition, the second controllable environment may comprise a plurality of parameters. For example, the second controllable environment may comprise a second temperature, humidity, pressure, airflow velocity, and/or inert gas.
In some embodiments, at least one of the first temperature, humidity, pressure, airflow velocity, and the inert gas may be the same as the second temperature, humidity, pressure, airflow velocity, and inert gas. Alternatively, or in addition, at least one of the first temperature, humidity, pressure, airflow velocity, and the inert gas may be different to the second temperature, humidity, pressure, airflow velocity, and inert gas. Any of the aforementioned parameters may be used to define the controllable environment of each chamber. More specifically, any combination of parameters may be used to define the controllable environment of each chamber.
In some embodiments, the temperature may comprise a temperature gradient. Alternatively, or in addition, the airflow may be used to maintain a homogeneous temperature within the chamber. For example, heat may be applied within the first and/or second chamber in the form of hot air. The velocity of the air being introduced into the chamber may ensure that the air is circulated throughout the chamber. The circulated air may ensure thermal homogeneity. The humidity may be the relative humidity within the chamber. The relative humidity may be between 0%-100% and, more preferably between 30-70% and most preferably, approximately 50%. The pressure may be approximately atmospheric pressure. Alternatively, the pressure may be elevated above atmospheric pressure. For example, the pressure may be up to 1.5, 2, 2.5 or 3 times atmospheric pressure. Moreover, in some embodiments, the first and/or second chamber may be filled with inert gas. For example, the chamber may be filled with a Nobel gas. Alternatively, or in addition, the chamber may be filled with Nitrogen or Argon.
The dyed textile may be continuously conveyed along the processing line. For example, the dyed textile may be continuously conveyed into the first chamber. At least a part of the processing line may be automated. Alternatively, the entire processing line may be automated. Accordingly, the dyed textile may be automatically conveyed into the first chamber.
Moreover, the dyed textile may be continuously conveyed into the second chamber. The dyed textile may be automatically conveyed into the second chamber. Alternatively, or in addition, the dyed textile may be manually conveyed into the second chamber. The dyed textile may be a textile comprising dyestuff.
The method may further comprise adjusting the first and/or second controllable environment based on a characteristic of a textile to be dyed; a dyestuff for use in dyeing the textile and/or the dyed textile. The first and/or second environment may be adjusted in use. In other words, the first and/or second environment may be adjusted whilst the processing line is conveying the textile.
The characteristics of the dyestuff may comprise the concentration, colour, shade, pantone, reflectivity, water content, colour index number and/or molecular weight of the dyestuff. For example, a dyestuff with a higher molecular weight may require more energy in order to fixate to the textile. A dyestuff with a higher molecular weight may result in the dyed textile being stored in the first and/or second chamber for a longer time period and/or at a greater temperature. Moreover, the characteristics of the dyed textile and/or the textile to be dyed may comprise the basis weight, absorbance capacity, reflectivity, water content, thickness, diameter and/or batch code of the textile.
The textile to be dyed and/or the dyed textile may comprise polyester, cotton, wool, nylon, Elastane, and/or silk. However, any other textile or textile product may be used. Moreover, the dyestuff may comprise dispersed dyes, pigments, acid dyes and/or reactive dyes. For example, in some embodiments, the textile may be polyester and the colourant may be a dispersed dyestuff. Alternatively, the textile may be cotton and the colourant may be a reactive dyestuff. In some embodiments, the textile may be cotton and the colourant may be a pigment dyestuff. Alternatively, the textile may be nylon and the colourant may be an acid dyestuff.
Alternatively, or in addition, the characteristics of the textile to be dyed and/or the dyestuff used to dye the textile may be determined before the textile has been dyed, whilst the textile is being dyed and/or after the textile has been dyed. This enables the plurality of characteristics to be measured throughout a dyeing and fixation process.
Consequently, the method may comprise determining the textile and/or dyestuff characteristics before, during and after the textile has been dyed and adjusting the first and/or second controllable environments based on the determined characteristics. A comparison between characteristics measured at different points within the method may also be used to optimise the controllable environment within each chamber. This can increase the quality and, more specifically, the colourfastness of the dyed textile.
The first chamber may comprise a first internal temperature. The second chamber comprises a second internal temperature lower than the first internal temperature. Having a second temperate which is lower than the first temperature allows the energy applied to the textile within the first chamber to be utilised, at least in part, within the second chamber. This decreases the energy required to heat the textile in the second chamber.
For example, the method may comprise temporarily storing the dyed textile in a first chamber having a first internal temperature for a first time period; and temporarily storing the dyed textile in a second chamber having a second internal temperature for a second time period, wherein the first internal temperature is greater than the second internal temperature. However, in some embodiments, the second chamber may comprise a second internal temperature substantially equal to or higher than the first internal temperature.
Subjecting a dyed textile to a first chamber having a first temperature for a first time period and a second chamber having a second temperate for a second time period may improve the colourfastness and/or softness of the dyed textile. For example, the use of two chambers may result in an almost complete fixation of the dyestuff onto the textile. This may be due to the loosely bound dyestuff molecules on the surface of the textile fibres now being more strongly bound to the fibres. Accordingly, only a very small concentration of dyestuff molecules is able to be leveraged away from the textile during colourfastness testing.
The first internal temperature may be between 140° C. and 230° C. Temporarily storing the dyed textile between 140° C. and 230° C. enables the dyestuff to fixate locally around individual fibres. This improves the resulting colourfastness of the dyed textile. More specifically, the first internal temperature may be between 150° C. and 215° C. Most specifically, the first internal temperature may be between 160° C. and 200° C.
The second internal temperature may be between 120° C. and 200° C. A lower temperature in the second chamber enables the textile to cool slightly. This cooling effect can be used to improve the softness of the textile. Moreover, a lower temperature within the second chamber removes the requirement for further heat to be applied to the textile, which reduces the overall energy used during the process. In some embodiments, the second internal temperature is between 130° C. and 190° C. and/or 140° C. and 180° C.
The second time period may be greater than the first time period. The first time period may be at least 10 minutes. More preferably, the first time period may be between 30 minutes-4 hours. Most preferably, the first time period may be between 45 minutes-2 hours. However, in some embodiments, the first time period may be up to 5 hours, 8 hours, 10 hours or 12 hours. For example, the dyed textile may be temporality stored within the first chamber overnight.
The second time period may be at least 2 hours. For example, the second time period may be between 5-60 minutes or 10-30 minutes. Alternatively, the second time period may be up to 4 hours, 6 hours, 8 hours, 12 hours, 24 hours or 48 hours. However, in some embodiments, the second time period may be more than 48 hours.
The method may further comprise determining a cool down rate for the dyed textile, and adjusting the controllable environment of the first and/or second chamber based on the cool down rate. In this context, the cool down rate may be defined as the time taken for the textile to decrease by 1° C. Moreover, the cool down rate may be determined based on the characteristics of the textile to be dyed, dyed textile and/or dyestuff. The cool down rate may be calculated prior to the textile dyeing 10 process. The cool down rate may be adjusted in order to improve the softness and/or colourfastness of the dyed textile.
The method may further comprise temporarily storing the dyed textile at a plurality of different temperatures in the second chamber. For example, the second chamber may be configured to subject the dyed textile to a plurality of different temperatures within the temperature gradient. The temperature gradient within the second chamber may define a cool down rate for the dyed textile. In some embodiments, the second chamber may comprise a plurality of heater. Each heater may be configured to produce a different temperature. The plurality of heaters may generate a temperature gradient within the second chamber.
In some embodiments, the dyed textile is temporarily stored at each temperature within the temperature gradient for up to 1 hour. Alternatively, the dyed textile may be temporarily stored at each temperature within the temperature gradient for up to 10 minutes, 20 minutes, 30 minutes 45 minutes, 1 hour, 2 hours, 3 hours or 4 hours.
The method may further comprise conveying the dyed textile through a plurality of different temperatures within the second chamber. Conveying the textile through the second chamber may comprise temporarily storing the dyed textile within the second chamber. The plurality of different temperatures within the second chamber may generate a temperature gradient. The thermal energy used to provide the temperature gradient within the second chamber may be received, at least in part, by the dyed textile. The dyed textile may cool as it is conveying through the second chamber.
The second chamber may comprise a proximal end having a first opening, wherein the first opening is configured to receive the dyed textile. In some embodiments, the first opening is configured to receive a dyed textile roll. The second chamber may comprise a distal end having a second opening, wherein the second opening is configured to output the dyed textile. In some embodiments, the second opening is configured to output the dyed textile roll. The first and second opening may each comprise a door and/or seal. The proximal end may be at a higher temperature than the distal end. For example, the proximal end may be approximately 180° C. and the distal end may be approximately 140° C. There may be a substantially linear temperature gradient between the proximal end and the distal end. In use, a dyed textile or, more specifically, the dyed textile roll may move between the proximal end and the distal end. It may take at least 2 hours for the dyed textile to move between the proximal end and the distal end.
The method may further comprise consolidating the dyed textile into a roll within the first chamber. Alternatively, the textile may be consolidated into any spatially condensed structure. For example, the method may comprise consolidating the textile into a folded pile, concertina pile or unstructured pile. Consolidating the textile within the first chamber increases the amount of dyed textile that can be stored in the second chamber. Moreover, consolidating the dyed textile removes airflow and/or eddy currents within the textile. This improves the dyestuff fixation process, therefore improving the resulting colourfastness.
The speed at which the dyed textile is conveyed into the first chamber may be varied. For example, the dyed textile may be conveyed into the first chamber at a faster rate than it is conveyed into the second chamber. This may create an excess of dyed textile within the first chamber. The consolidated textile roll may be separated from the processing line and conveyed into the second chamber. Simultaneously, the excess dyed textile may begin consolidating to generate a second roll within the first chamber. Additionally, the speed at which the dyed textile is conveyed into the first chamber may be reduced until the excess dyed textile has been consolidated. This may reduce the downtime within the process. Alternatively, in some embodiments, the processing line is paused in order to remove the roll from the first chamber.
The roll may be 50-3000 m in length. More specifically, the roll may be between 500m-1500m or approximately 1000m in length.
The method may further comprise temporarily storing a plurality of dyed textile rolls in the second chamber. Temporarily storing a plurality of dyed textiles, or more specifically, dyed textile rolls in the second chamber increases the thermal mass and reduces the free space within the chamber. This reduces the energy required to maintain the controllable environment within the chamber.
Moreover, in some embodiments, the method comprises conveying a plurality of dyed textile rolls through a plurality of different temperatures within the second chamber. Once a dyed textile roll has been conveyed a predetermined distance through the second chamber, a subsequent dyed textile roll may be added to the second chamber.
As previously disclosed, the second chamber may comprise a plurality of temperatures and/or a temperature gradient. Each dyed textile roll may cool as it is conveyed through the second chamber. Therefore, the thermal energy used to provide the temperature gradient within the second chamber may be received, at least in part, by the addition of a subsequently dyed textile roll. For example, the subsequently dyed textile roll may be at the temperature of approximately 180° C. when it enters the second chamber. When the subsequently dyed textile roll enters the second chamber, the initially dyed textile roll may be at a temperature that is less than 180° C. For example, the initially dyed textile roll's temperature may have dropped to be approximately 175° C., 170° C., 165° C., or 160° C.
Each roll within the second chamber may be rotated. For example, each roll may be rotated about the roll axis. The roll axis may be the axis about which the textile is wrapped in order to generate the roll. More specifically, each roll within the second chamber may be constantly rotated. Additionally, each roll may be conveyed along a conveyor within the second chamber. More specifically, each roll may be conveyed along a conveyor within the second chamber when a new roll is added. in some embodiments, a new roll is added every 10-30 minutes.
In some embodiments, the method further comprises monitoring and/or controlling the cool down rate of the dyed textile after it has left the second chamber. This may further improve colourfastness. For example, the dyed textile may leave the second chamber at approximately 140° C. The dyed textile roll may be left to slowly cool in storage. This may further improve the colourfastness of a dyed textile when compared to a sample taken and immediately cooled in an unconsolidated form.
The method may further comprise conveying the dyed textile through a fixation chamber having a third controllable environment. For example, the dyed textile may be conveyed through the fixation chamber before being temporarily stored in the first and/or second chamber. The fixation chamber may be configured to reduce the water content of a textile comprising a dyestuff and simultaneously initiate the fixation process between the dyestuff and the textile. The third controllable environment may have a third internal temperature.
The temperature within the fixation chamber may be between 180° C. and 220° C. The third controllable environment may have a third internal temperature. Heating the textile between 180° C. and 220° C. within the fixation chamber causes fixation of the dyestuff to/within the textile. For example, heating the dyed textile to between 180° C. and 220° C. may allow at least 90% of the dyestuff to diffuse into the textile fibres. However, in some embodiments, heating the dyed textile to between 180° C. and 220° C. may allow at least 80%, 85%, 90%, 93%, 95%, 96%, 97%, 98% or 99% of the dyestuff to diffuse into the textile fibres.
Subsequently storing the dyed textile between 160° C. and 200° C. in the first chamber may allow for local diffusion of the remaining dyestuff into the textile fibres. For example, at least 85%, 90%, 93%, 95%, 96%, 97%, 98%, 99% or 100% of the dyestuff may diffuse into the textile fibres within the first chamber.
The fixation chamber may be configured to heat the dyed textile to the third temperature for between 1 minute and 15 minutes. In some embodiments, the fixation chamber may be configured to heat the dyed textile to the third temperature for between 0 and 20 minutes; 1 and 15 minutes; 2 and 10 minutes; 3 and 8 minutes; or approximately 5 minutes.
The method may further comprise transporting the second chamber to a new location whilst the dyed textile is temporarily stored therein. Transporting the dyed textile to a new location whilst it is being temporarily stored within the second chamber reduces the overall time taken for an end-user to receive the dyed textile after having requested it. This increases the overall efficiency of the process.
In some embodiments, the method comprises applying a dyestuff to an undyed textile. More specifically, the method may comprise conveying an undyed textile along a processing line and applying a dyestuff to the undyed textile. A single processing line may be used to both apply dyestuff to an undyed textile and to improve the colourfastness of the dyed textile. Alternatively, in some embodiments, at least two separate processing lines may be used. For example, a first processing line may be configured to apply a dyestuff to an undyed textile and a second processing line may be configured to improve the colourfastness of a dyed textile.
The method may further comprise applying a dyestuff comprising a colourless dispersant to an undyed textile. The colourless dispersants may further improve the resulting colourfastness. For example, the use of a colourless dispersant may replace the washing process. This significantly reduces the total amount of water required to produce a dyed textile.
The method may further comprise dispensing dyestuff onto the textile via an array of flow channel dispensers. The array of flow channel dispensers may be digitally controlled. Digital control of the array of flow channel dispensers may provide versatility such as real-time or near real-time colour inconsistency correction and/or near-instant colour switching on the same processing line can be achieved. The application of dyestuff to a textile via an array of flow channel dispensers as opposed to, for example, the traditional method of soaking the textile in a disperse dye bath, allows for the deposition of exactly the correct dose of dyestuff according to the measured parameters of the textile.
Accordingly, the present invention relates to methods for improving the colourfastness and/or hand-feel of a dyed textile. The invention enables continuous roll-to-roll dyeing methods to achieve improved colourfastness and hand-feel, eliminating the need for additional downstream processing and washing.
The invention comprises two methods that may be used individually or in combination. Therefore, according to the present invention, there is also provided a method for improving the colourfastness of a dyed textile, the method comprising conveying a dyed textile along a processing line; applying a fluid to the dyed textile at a first position on the processing line and subsequently removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line; conveying the dyed textile into a first chamber having a first controllable environment and temporarily storing the dyed textile in the first chamber for a first time period; and conveying the dyed textile into a second chamber having a second controllable environment and temporarily storing the dyed textile in the second chamber for a second time period.
The method may further comprise removing contaminants from the removed fluid; and re-applying the fluid to the dyed textile. The fluid may be sprayed onto the dyed textile.
The method may further comprise mechanically agitating the dyed textile. The method may further comprise adjusting the first and/or second controllable environment based on a characteristic of a textile to be dyed; a dyestuff for use in dyeing the textile and/or the dyed textile. The first chamber may comprise a first internal temperature. The second chamber may comprise a second internal temperature lower than the first internal temperature.
The method may further comprise temporarily storing the dyed textile at a plurality of different temperatures in the second chamber. Alternatively, or in addition, the method may further comprise consolidating the dyed textile into a roll within the first chamber. The method may further comprise conveying the dyed textile through a fixation chamber having a third controllable environment. The method may further comprise dispensing dyestuff onto the textile via an array of flow channel dispensers.
Consequently, there is also provided a method for improving the colourfastness of a dyed textile, the method comprising: conveying a textile along a processing line; dispensing dyestuff onto the textile via an array of flow channel dispensers; conveying the dyed textile through a fixation chamber having a first controllable environment; applying a fluid to the dyed textile at a first position on the processing line and subsequently removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line; conveying the dyed textile into a first chamber having a first controllable environment and temporarily storing the dyed textile in the first chamber for a first time period; and conveying the dyed textile into a second chamber having a second controllable environment and temporarily storing the dyed textile in the second chamber for a second time period.
In some embodiments, the dyestuff applied to the textile may comprise a standard formulation. The standard formulation may comprise approximately 5 g/L Levafix Blue (reactive dye); 5 g/L Soda Ash (alkaline buffer); 1 g/L Caustic Soda (catalyst); 1 g/L Meropan DA (sequestering agent); 2 g/L of Wetting agent; 5 g/L of Humectant: Glycerol or PEG 400; and 0.5 g/L Sodium Alginate (levelling agent). This formulation may be used to dye a cotton textile, for example.
According to the present invention, there is also provided an apparatus for improving the colourfastness of a dyed textile, the apparatus comprising a processing line for conveying a textile in a first direction; a reverse osmosis unit including a fluid reservoir for retaining a fluid and a filtration unit for removing contaminants from the fluid; a fluid applicator configured to apply the fluid to the textile in a second direction substantially opposite to the first direction; a fluid removal device configured to remove the fluid from the textile and return it to the reverse osmosis unit.
The application of fluid enables the movement of textile fibres and acts to improve the overall colourfastness. Applying a fluid to the textile via a fluid applicator and subsequently removing the fluid from the textile via a fluid removal device may improve the colourfastness of the textile. Moreover, excess dyestuff within or on the dyed textile may be removed along with the fluid by the fluid removal device.
The fluid removal device may be downstream of the fluid applicator. Alternatively, or in addition, the fluid removal device may be located opposite the fluid applicator. The fluid may pass through the textile.
Contaminants are removed via reverse osmosis in the reverse osmosis unit configured to force the contaminated fluid through a semi-permeable membrane to remove contaminants. The reverse osmosis unit may be configured to remove salts, ions and/or polymers such as lignin from the fluid
The reverse osmosis unit may comprise a fluid reservoir in communication with the fluid applicator. The reverse osmosis unit may further comprise a filtration unit configured to receive fluid from the fluid removal device, remove contaminants from within the removed fluid and supply decontaminated fluid back into the fluid reservoir. The filtration unit may be in fluid communication with the fluid reservoir. The fluid applied to and removed from the textile may be recirculated via the fluid reservoir.
The reverse osmosis unit may recover above 60% of the water used within the apparatus or, more specifically, above 70% of the water or, most specifically, above 80% of the water used within the apparatus. Alternatively, or in addition, the filtration unit may have an efficiency of above 90% or, more preferably, above 95%, or most preferably, above 98%.
Recirculating and/or regenerating the fluid uses significantly less water and energy than alternative solutions that require large volume wash baths. The filtration unit may comprise a plurality of filters of decreasing pore size. The filtration unit may be located between the fluid reservoir and the fluid applicator. Alternatively, or in addition, the filtration unit may be located between the fluid removal device and the fluid reservoir. The filtration unit may be located in line with the fluid applicator, fluid reservoir and fluid removal device.
Alternatively, or in addition, the filtration unit may be located in parallel with the fluid reservoir. Fluid may flow out of the fluid reservoir, through the filtration unit and back into the fluid reservoir. The reverse osmosis unit may comprise a plurality of filtration units. The filtration unit may be configured to remove dyestuff particles from the fluid.
The fluid reservoir may be at least partially filled with a liquid. Alternatively, or in addition, the fluid reservoir may be at least partially filled by a gas. The liquid may be water. The gas may be air.
The fluid applicator and reverse osmosis unit may form a fluid flow loop. The fluid flow loop may be a continuous fluid flow loop.
Alternatively, or in addition, contaminants may be removed via Ozonation. Ozonation may be used to remove Oxidises chemicals from the fluid. The fluid decontamination process may be a combination of filtration, reverse osmosis and/or Ozonation.
The fluid applicator may comprise a spray nozzle. The spray nozzle may evenly distribute the fluid across the textile. Moreover, the fluid applicator may comprise a plurality of spray nozzles. The plurality of spray nozzles may be an array of spray nozzles. An array of spray nozzles may ensure that the textile is entirely subjected to the fluid being sprayed. In some embodiments, the fluid applicator is a liquid applicator.
More specifically, in some embodiments, each spray nozzle may be configured to force the fluid through the textile, in use. Alternatively, or in addition, the fluid may be sprayed onto, into and/or through the textile, in use.
The fluid removal device may be configured to generate a partial vacuum, in use. The partial vacuum may suck the fluid onto, into and/or through the textile, in use. This may remove the fluid from the textile, in use, without touching and/or damaging the textile.
Alternatively, or in addition, the fluid removal device may be configured to generate a high velocity airflow configured to pass through the dyed textile. For example, the dyed textile may be conveyed between the high velocity airflow and the vacuum.
The apparatus may further comprise a mechanical agitator. The mechanical agitator may comprise a roller. A singular roller may be advantageous as it provides less mechanical agitation than a pair of rollers which may allow for more delicate textiles to have excess dyestuffs dislodged without damaging the textile.
The mechanical agitator may comprise a pair of rollers. At least one of the rollers may be a roller used to convey the dyed textile along the processing line. The rollers may be reciprocating rollers. At least one roller may be configured to reciprocate in a first direction, parallel to the movement of the dyed textile, in order to stretch the dyed textile. Alternatively, or in addition at least one roller may be configured reciprocate in a second direction, transverse to the movement of the dyed textile, in order to shear the dyed textile. The rollers may reciprocate up to 100 mm. More specifically, the rollers may reciprocate up to 75 mm, 50 mm, 30 mm, 20 mm or 10 mm. For example, the rollers may reciprocate ±10 mm away from a starting position. However, in some embodiments, the rollers may reciprocate ±25 mm away from a starting position. Alternatively, or in addition, the mechanical agitator may be configured to vibrate. More specifically, the roller(s) may be configured to vibrate. This may improve the mechanical agitation applied to the textile.
There may be a plurality of mechanical agitators. Each agitator may be configured to contact the textile being conveying, in use. The mechanical agitator may move the textile fibres, in use.
The mechanical agitator may comprise a textured surface configured to contact the textile, in use. The textured surface may be configured to deliver mechanical forces to the textile. This is advantageous as the mechanical forces acting on the textile may dislodge excess dyestuffs that would otherwise remain in the textile, thus further improving the colourfastness of the textile.
The textured surface of the roller may be knurled.
The textured surface of the roller may be spiralled.
Alternatively, or in addition, the mechanical agitator may comprise a brush. The brush may be configured to contact the textile, in use.
The mechanical agitator may comprise at least one axis relative to which it may move. For example, the mechanical agitator may comprise a longitudinal axis along its most elongate length. The agitator may be configured to rotate about its longitudinal axis. Alternatively, or in addition, the agitator may be configured to move along its longitudinal axis.
For example, a roller in contact with the textile may be configured to rotate about a longitudinal axis which is substantially perpendicular to the textile being conveyed. Conversely, a brush in contact with the textile may be configured to move along a longitudinal axis which may be substantially perpendicular or parallel to the textile being conveyed.
The mechanical agitator may be configured to move at a different speed to speed to textile being conveyed. This may enhance the effectiveness of mechanical agitation.
The apparatus may further comprise a heat exchanger. The heat exchange element is configured to remove thermal energy from decontaminated/contaminated fluid and apply said thermal energy to the fluid to be applied to the textile. This will enable thermal energy, which would otherwise be lost, to be re-used to assist in heating the fluid to be applied to the desired temperature. This means less energy is required from external sources to heat the fluid to be applied to its required temperature.
The use of a reverse osmosis unit and heat exchanger in-line to recirculate heat from the first to the last stage of the process reduces the water emissions from the process to less than 10 L/kg at ambient temperature or, more specifically, to less than 1 L/Kg at ambient temperature. Moreover, heat losses are reduced to less than 30% (i.e. less than 0.20 MJ/kg) or, more specifically, less than 20% (i.e. less than 0.15 MJ/kg) or, most specifically, less than 10% (i.e. less than 0.10 MJ/kg).
Alternatively, or in addition, there is also provided an apparatus for improving the colourfastness of a dyed textile, the apparatus comprising a processing line configured to convey dyed textile into a first chamber having a first controllable environment, wherein the first chamber is configured to temporarily store the dyed textile for a first time period; and a second chamber having a second controllable environment, wherein the second chamber is configured to temporarily store the dyed textile for a second time period.
As previously disclosed, each of the first and second predetermined controllable environments may comprise a first and second temperature, humidity, pressure, airflow velocity, and/or inert gas, respectively.
The second chamber may be directly adjacent to the first chamber. Positioning the second chamber directly adjacent to the first chamber reduces the thermal energy lost from the textile as it travels therebetween.
The second chamber may be mobile. The second chamber may be used to transport the dyed textile, thus utilising the time whilst the textile is within the second chamber to also move and/or deliver the textile to a potential user. This increases the overall efficiency of the dyeing process. For example, the second chamber may be a thermally insulated skip or trolley. Alternatively, or in addition, the second chamber may be an actively heated skip or trolley. The second chamber may comprise at least one wheel, roller and/or castor. More specifically, the second chamber may comprise a plurality of wheels, rollers and/or castors.
The first chamber may be downstream of the second chamber. As previously disclosed, the first chamber may comprise a first internal temperature and the second chamber may comprise a second internal temperature lower than the first internal temperature. Positioning the first chamber downstream of the second chamber enables the textile to be most efficiently heated to the greater of the two temperatures, before being able to cool slightly as it travels to and through the second chamber.
The second chamber may comprise a temperature gradient. For example, the dyed textile may enter the second chamber at an elevated temperature. The thermal energy within the textile may have been applied during the first and/or third chamber. Therefore, the temperature gradient may be formed by the natural cooling of the textile as it is conveyed through the second chamber.
The first chamber may comprise a cylindrical core configured to receive the dyed textile and form a dyed textile roll, in use. The cylindrical core may be a tube. A core configured to receive the dyed textile and form a roll efficiently packaging the dyed textile. This consolidated form is easier the move, store and transport. Moreover, the cylindrical core may be configured to maintain pressure equally throughout the roll. The core may be cardboard, plastic or metal.
The apparatus may comprise a plurality of cores. For example, the apparatus may comprise two cores. Each core may be configured to receive dyed textile sequentially.
The first chamber may comprise a cutting module configured to cut the textile and generate a discrete dyed textile roll. The cutting module may comprise a blade. Cutting the textile to produce a discrete dyed textile roll enables each roll to comprise a predetermined length of dyed textile. This improves the packaging of the rolls.
The second chamber may be configured to receive a plurality of discrete dyed textile rolls. Enabling the second chamber to receive a plurality of discrete dyed textile rolls increases the efficiency of the apparatus. A plurality of textile rolls provides greater thermal mass, which reduces the amount of heat required in order to generate and maintain the predetermined temperature.
Alternatively, or in addition, each discrete dyed textile roll may travel through the second chamber, in use. Moreover, as previously disclosed, the second chamber may comprise a temperature gradient. The dyed textile may cool as it transitions through the second chamber. Accordingly, the thermal energy used to provide the temperature gradient within the second chamber may be received, at least in part, by the addition of a subsequently dyed textile roll. The subsequently dyed textile roll may be approximately 180° C. when it enters the second chamber. When the subsequently dyed textile roll enters the second chamber, the initially dyed textile roll may be less than 180° C. For example, the initially dyed textile roll may be approximately 175° C., 170° C., 165° C., or 160° C.
More specifically, the second chamber may comprise a proximal end having a first opening, wherein the first opening is configured to receive the discrete dyed textile roll. The second chamber may comprise a distal end having a second opening, wherein the second opening is configured to output the discrete dyed textile roll. The first and second opening may each comprise a door and/or seal. The proximal end may be at a higher temperature than the distal end. For example, the proximal end may be approximately 180° C. and the distal end may be approximately 140° C. There may be a substantially linear temperature gradient between the proximal end and the distal end. In use, a dyed textile roll may move between the proximal end and the distal end. It may take at least 2 hours for the dyed textile to move between the proximal end and the distal end. Once the dyed textile roll has moved a predetermined distance towards the distal end of the second chamber, a subsequent dyed textile roll may be added to the second chamber via the first opening.
The apparatus may further comprise a fixation chamber configured to receive the dyed textile. The fixation chamber may comprise a third controllable environment configured to heat the dyed textile to a third temperature. The fixation chamber may be configured to heat the textile to between 150° C. −240° C. Moreover, the time that the textile spends in the fixation chamber may be up to 10 seconds. Alternatively, the time that the textile spends in the fixation chamber may be up to 20 seconds, 30 seconds, 40 seconds or 60 seconds. However, in some embodiments, the time that the textile spends in the fixation chamber may more than 60 seconds. The fixation chamber may be configured to reduce the water content of a textile comprising a dyestuff and simultaneously initiate the fixation process between the dyestuff and the textile.
The fixation chamber may be positioned downstream of the first and second chamber. Alternatively, or in addition, the fixation chamber may be positioned upstream of a digital dyeing process. Alternatively, or in addition, the first and second chambers may be positioned upstream of a digital dyeing process. The digital dyeing process may be as described in WO 2020/208362, the disclosure in which is incorporated herein by reference. However, in some embodiments, the fixation chamber may be positioned upstream of an analogue dyeing process. For example, the fixation chamber may be positioned upstream of an exhaust dyeing process; pad dyeing process; spray deposition process; hot or cold transfer process and/or a dye bath.
The fixation chamber may comprise an infra-red (IR) or near infra-red (NIR) drying module configured to heat the dyed textile. IR or NIR is an efficient way to increase the temperature of the textile and fix the dyestuff thereon without damaging the textile. The energy supplied to the textile via IR or NIR can also be easily manipulated and optimised. Furthermore, the use of digital dyeing and/or infra-red drying may further limit the presence of aggregates on the surface of the textile fibres that can negatively impact colourfastness performance.
Accordingly, the present invention also relates to apparatus for improving the colourfastness and/or hand-feel of a dyed textile. The invention comprises two apparatus that may be used individually or in combination. Therefore, according to the present invention, there is also provided an apparatus for improving the colourfastness of a dyed textile, the apparatus comprising a processing line for conveying a textile; a fluid applicator configured to apply a fluid to the textile being conveyed; a fluid removal device configured to remove the fluid from the textile being conveyed, a first chamber configured to receive the conveyed textile, wherein the first chamber comprises a first controllable environment and wherein the first chamber is configured to temporarily store the dyed textile for a first time period; and a second chamber having a second controllable environment, wherein the second chamber is configured to temporarily store the dyed textile for a second time period.
Each of the aforementioned chamber environments may be digitally controlled. Alternatively, or in addition, the fluid applicator and/or fluid removal device may be digitally controlled. More specifically, the entire processing line may be controlled digitally. For example, the processing line may comprise a control unit. The control unit may comprise a processor. The control unit may be configured to control the environment within each chamber including but not limited to, the temperature and/or cool down rate, where applicable. Alternatively, in or in addition, the control unit may be configured to control the parameters of the processing line. This includes, but is not limited to, the speed at which the textile is conveyed along the processing line and/or the temperature of the processing line.
The processing line, chamber environments, fluid applicator, and/or fluid removal device may be digitally controlled, in use. Therefore, the processing line, chamber environments, fluid applicator, and/or fluid removal device may be digitally controlled whilst the processing line is conveying the textile.
The invention will now be further and more particularly described, by way of example only, with reference to the accompanying drawings.
More specifically, the method comprises applying a predetermined volume of fluid to the dyed textile at a first position on the processing line 120. The predetermined volume is based on the desired water content of the textile. The predetermined volume of fluid to be applied to the textile is calculated based on the mass flow rate of the textile along the processing line.
The total mass of fluid applied to the dyed textile is 100%-300% of the mass of the dyed textile. The fluid applied to the dyed textile at the first position is typically applied at 1-20 litres per minute. However, the rate volume of fluid being applied varies depending on the textile and dyestuff used. Moreover, the textile is typically conveyed along the processing line at 1-100 meters per minute (m/min). However, again, the rate at which the textile is conveyed along the processing line varies depending on the textile and dyestuff used.
The fluid applied to the dyed textile at the first position on the processing line 120 is sprayed. The method comprises spraying a fluid to the dyed textile at a first position on the processing line 120. The fluid is sprayed onto the dyed textile via a plurality of spray nozzles. The plurality of spray nozzles is configured to spray fluid across the entire width of the conveyed textile.
The fluid is removed from the textile by a vacuum. More specifically, the method comprises removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line 130 using a vacuum.
The method further comprises a fluid decontamination step 140. Accordingly, the method comprises conveying a dyed textile along a processing line 110; applying a fluid to the dyed textile at a first position on the processing line 120; subsequently removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line 130; removing contaminants from the removed fluid 140; and re-applying the fluid to the dyed textile 150.
The fluid being re-applied is re-applied at the first position on the processing line 120. However, in other embodiments, not illustrated in the accompanying drawings, the fluid being re-applied may be re-applied at a third position on the processing line.
The method is continuous. Accordingly, the method comprises: continuously conveying a dyed textile along a processing line 110; continuously applying a fluid to the dyed textile at a first position on the processing line 120; and subsequently, continuously removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line 130. Moreover, contaminates are continuously removed from the removed fluid 140 and the decontaminated fluid is continuously re-applying to the dyed textile 150. The continuously re-applied fluid 150 is applied to the dyed textile at the first position on the processing line. The decontaminated fluid is, at least in part, the fluid applied to the dyed textile at the first position on the processing line 120.
The method further comprises heating the fluid to above 40° C. Therefore, the fluid applied to the dyed textile at a first position on the processing line 120 is above 40° C. More specifically, the method comprises heating the fluid to above 55° C.
The method further comprises heating the first position on the processing line to 40-95° C. More specifically, the temperature of the environment at the first position on the processing line 120 is 40-95° C. Most specifically, the method comprises heating the first position on the processing line to 50-70° C. or approximately 60° C.
The method further comprises: determining a range of acceptable flow rates for the fluid being applied; monitoring the flow rate of the fluid being applied; and adjusting the flow rate of the fluid being applied if the flow rate of fluid being applied is outside of the range of acceptable flow rates. The fluid being applied is accurately monitored and can be adjusted, in use.
The method further comprises: mechanically agitating the dyed textile. Consequently, the method comprises: conveying a dyed textile along a processing line 110; applying a fluid to the dyed textile at a first position on the processing line 120; agitating the textile 125; subsequently removing at least 50% of the applied fluid from the dyed textile at a second position on the processing line 130; removing contaminants from the removed fluid 140; and re-applying the fluid to the dyed textile 150.
The mechanical agitation occurs between the fluid application step 120 and the fluid removal step 130. More specifically, the dyed textile is mechanically agitated via a pair of rollers configured to contact the textile being conveyed along the processing line. The rollers are nip rollers. The mechanical agitation occurs between the first and second position on the processing line.
The dyed textile is automatically conveyed into the first chamber. Conversely, the dyed textile is manually conveyed into the second chamber.
The method further comprises adjusting the first and/or second controllable environment based on a characteristic of a textile to be dyed; a dyestuff for use in dyeing the textile and/or the dyed textile 215. The characteristics of the dyestuff comprise the concentration, colour, shade, pantone, reflectivity, water content, colour index number and/or molecular weight of the dyestuff. Moreover, the characteristics of the dyed textile and/or the textile to be dyed comprise the basis weight, absorbance capacity, reflectivity, water content, thickness, diameter and/or batch code of the textile.
The first chamber is maintained at a first internal temperature and the second chamber is maintained at a second internal temperature. The second internal temperature is lower than the first internal temperature.
More specifically, the first internal temperature is between 140° C. and 240° C. and the second internal temperature is between 120° C. and 220° C. Most specifically, the first internal temperature is between 160° C. and 220° C. and the second internal temperature is between 140° C. and 200° C.
The second time period is greater than the first time period. More specifically, the first time period is at least 10 minutes and the second time period is at least 30 minutes. Most specifically, the first time period is at least 40 minutes and the second time period is at least 2 hours.
The method further comprises: determining a cool down rate for the dyed textile 250 and adjusting the controllable environment of the first and/or second chamber based on the cool down rate 260. The cool down rate is defined as the time taken for the textile to decrease by 1° C. Moreover, the cool down rate is determined based on the characteristics of the textile to be dyed, dyed textile and/or dyestuff. The cool down rate is calculated prior to the textile dyeing process.
More specifically, the method comprises: temporarily storing the dyed textile at a plurality of different temperatures in the second chamber for a second time period 240. Most specifically, the method comprises conveying the dyed textile through a plurality of different temperatures within the second chamber for a second time period 240. Accordingly, the second chamber comprises a temperature gradient.
The method further comprises consolidating the dyed textile into a roll within the first chamber 270. Moreover, the speed at which the dyed textile is conveyed into the first chamber is varied, in use. More specifically, the dyed textile is conveyed into the first chamber at a faster rate than it is conveyed into the second chamber. This creates an excess of dyed textile within the first chamber. The consolidated textile roll is then separated from the processing line and conveyed into the second chamber. Simultaneously, the excess dyed textile begins consolidating to generate a second roll within the first chamber. Additionally, the speed at which the dyed textile is conveyed into the first chamber is reduced until the excess dyed textile has been consolidated.
The consolidated textile roll comprises 50-3000m of dyed textile. More specifically, the roll comprises 500m-1500m or approximately 1000m of dyed textile. Moreover, each roll within the second chamber is rotated about its roll axis, wherein the roll axis is the axis about which the textile is wrapped in order to generate the roll.
More specifically, the method comprises temporarily storing a plurality of dyed textile rolls in the second chamber 240. Once a first dyed textile roll has been conveyed a predetermined distance through the second chamber, a subsequent dyed textile roll is added to the second chamber. As previously disclosed, the second chamber comprises a temperature gradient. Accordingly, each dyed textile roll cools as it is conveyed through the second chamber.
The method further comprises conveying the dyed textile through a fixation chamber having a third controllable environment 280. More specifically, the dyed textile is conveyed through the fixation chamber before being temporarily stored in the first and/or second chamber. The fixation chamber is configured to reduce the water content of a textile comprising a dyestuff and simultaneously initiate the fixation process between the dyestuff and the textile.
The third controllable environment is maintained at a third internal temperature. More specifically, the temperature within the fixation chamber is between 180° C. and 220° C. Moreover, the fixation chamber is configured to heat the dyed textile to the third temperature for between 1 minute and 15 minutes. More specifically, the fixation chamber is configured to heat the dyed textile to the third temperature for between 3 and 8 minutes.
The method further comprises removing contaminants from the removed fluid 140; and re-applying the fluid to the dyed textile 150. Moreover, the method comprises mechanically agitating the dyed textile 125, wherein the mechanical agitation occurs between the fluid application 120, 150 and the fluid removal 130.
In some embodiments, not illustrated in the accompanying drawings, the method may further comprise dispensing dyestuff onto the textile via an array of flow channel dispensers. The dyestuff may be dispensed onto the textile prior to the fluid application. Moreover, the dyestuff may comprise a colourless dispersant.
The fluid applicator 430 and fluid removal device 440 are located within a chamber 480. The internal environment of the chamber 480 is heated. More specifically, the internal environment of the chamber 480 is between 40° C. and 95° C. Most specifically, the internal environment of the chamber 480 is between 50° C. and 70° C. Moreover, the fluid 435 is heated. The fluid 435 is heated above 40° C. More specifically, the fluid is heated to 50° C.-70° C.
The apparatus 400 further comprising a reverse osmosis unit 445. The reverse osmosis unit 445 comprises a filtration unit 455 and a fluid reservoir 450. The filtration unit 455 is configured to receive fluid from the fluid removal device 440, remove contaminants from within the removed fluid 435 and supply decontaminated fluid to the fluid applicator 430. More specifically, the filtration unit 455 is in fluid communication with the fluid reservoir 450 and is located between the fluid removal device 440 and the fluid reservoir 455. The filtration unit 455 comprise a plurality of filters each having a different pore size.
The fluid applicator 430 comprises a spray nozzle. The fluid is sprayed onto the textile, in use. More specifically, the fluid applicator 430 comprises a first spray head 432 and a second spray head 434. Each spray head comprises a plurality of spray nozzles. Moreover, the fluid removal device 440 comprises a vacuum. The fluid removal device 440 is configured to generate a partial vacuum, in use.
The apparatus 400 further comprises a mechanical agitator 460. The mechanical agitator 460 comprises a roller 462. More specifically, the mechanical agitator 460 comprises a pair of rollers 462, 464. The rollers 462, 464 are reciprocating rollers. The rollers reciprocate ±10 mm away from a starting position. Each roller 462, 464 is configured to contact the textile 420 being conveying, in use. The mechanical agitator 460 is configured to move the textile fibres, in use. More specifically, the mechanical agitator 460 comprises a textured surface. Most specifically, each roller 462, 464 comprises a textured surface. Some examples of rollers have textured surfaces are shown in
The first chamber 530 comprises a cylindrical core 532 configured to receive the dyed textile 420 and form a dyed textile roll 534, in use. The first chamber 530 further comprises a cutting module 536 configured to cut the textile 420 and generate a discrete dyed textile roll 380. The cutting module 536 comprises a blade 538.
The second chamber 540 is upstream of the first chamber 530. Moreover, the second chamber 540 comprises wheels 542. The second chamber 549 is mobile. Additionally, the second chamber 540 is configured to receive a plurality of discrete dyed textile rolls 380.
The second chamber 540 comprises a temperature gradient. More specifically, the second chamber 540 comprises a proximal end 544 having a first opening. The first opening 545 is configured to receive the dyed textile 380. The second chamber 540 comprises a distal end 546 having a second opening 547. The second opening 547 is configured to output the dyed textile rolls 380. The first 545 and second 547 opening each comprises a door and/or seal. The proximal end 544 is at a higher temperature than the distal end 546. More specifically, the proximal end 544 is at approximately 180° C. and the distal end 547 is at approximately 140° C. There is a substantially linear temperature gradient between the proximal end and the distal end. The dyed textile rolls 380 are conveyed from the proximal end 544 of the second chamber 540 to the distal end 546 of the second chamber 530. More specifically, dyed textile rolls 380 are conveyed from the proximal end 544 of the second chamber 540 to the distal end 546 of the second chamber 530 via a conveyor belt 548.
The apparatus 600 further comprising a reverse osmosis unit 445 configured to receive fluid from the fluid removal device 440. The reverse osmosis unit comprises a filtration unit 455 and fluid reservoir 450. The filtration device 455 is configured to remove contaminants from within the removed fluid 435 and supply decontaminated fluid to the fluid applicator 430. More specifically, the filtration unit 455 is in fluid communication with the fluid reservoir 450 and is located between the fluid removal device 440 and the fluid reservoir 450.
Moreover, the apparatus 600 comprises a processing line 410 for conveying a textile 420. The processing line 410 is defined by a plurality of rollers 410 configured to define the path along which the dyed textile is conveyed. Any number of rollers 410 may be used. Each of the plurality of rollers 410 is configured to move relative to each other in order to extend or reduce the length of the processing line. This may be used to control the mass flow rate of the textile at a given position on the processing line.
The apparatus 600 further comprises a fixation chamber 610 configured to receive the dyed textile 420. The fixation chamber 610 comprises a third controllable environment configured to heat the dyed textile 420 to a third temperature. More specifically, the fixation chamber is configured to heat the textile to between 150° C.-240° C. Moreover, the textile remains in the fixation chamber for 10-60 seconds.
The fixation chamber 610 is positioned downstream of the fluid applicator 430, the fluid removal device 440, the first chamber 530 and the second chamber 540. Moreover, the fixation chamber 610 is positioned upstream of a digital dyeing process, not shown in the accompanying drawings. The digital dyeing process is as described in WO 2020/208362.
The fixation chamber 610 comprises a drying unit 620 located above the dyed textile 420. The drying unit 620 is configured to discharge energy as electromagnetic waves. The drying unit emits between 20 kW and 200 kW of energy. For example, the drying unit is configured to transfer approximately 50 kW of energy to the dyed textile. A 90-150KW drying unit is used. The energy emitted is in the form of Infra-Red (IR), Near Infra-Red (NIR), Mid Infra-Red (MIR), microwave and/or Ultraviolet (UV). However, in some embodiments not shown in the accompanying drawings, a plasma heater may be used.
The drying unit 620 further comprises an airflow configured to remove any vapour and/or humidity away from the vicinity of the dyed textile 420. The airflow is configured to remove up to 5 litres of water vapour per minute from the vicinity of the textile. More specifically, the textile 420 enters the fixation chamber 610 with a water content of approximately 25%. The textile leaves the fixation chamber with a water content of 0%-10%.
The fixation chamber 610 further comprises a reflector 630 located beneath the dyed textile 420. The reflector 630 is configured to optimise the amount of discharged energy that is transferred to the dyed textile.
The fixation chamber 610 further comprises a temperature sensor 640 configured to measure the temperature of the dyed textile. The dyed textile enters the fixation chamber at approximately room temperature, which may be between 5° C. and 45° C. degrees, but more preferably may be between 10° C. and 35° C. degrees and most preferably may be between 15° C. and 30° C. The temperature of the dyed textile 420 within the fixation chamber 610 is increased by 5° C. to 240° C. For example, the textile may enter the fixation chamber 610 at approximately 25° C. and leave the fixation chamber 610 at approximately 240° C.
The fixation chamber 610 is configured to enable dispensed dyestuff to diffuse into the textile substrate, chemically react with the substrate; and/or thermally fuse with the substrate.
The internal environment of the fixation chamber 610 is between 100° C. and 300° C. More specifically, the internal environment of the fixation chamber 610 is between 140° C. and 240° C. However, the temperature may be controlled and/or adjusted, in use.
The fluid applicator 430 is located within a chamber 480. The internal temperature of the chamber 480 is between 40-80° C., for example approximately 60° C. The fluid applicator 430 comprises twenty-four (24) nozzles configured to spray the fluid onto the dyed textile. The fluid is a liquid. The fluid is sprayed substantially vertically downwards (i.e. in the direction of gravity). The sprayed fluid fans out between the spray nozzle and the dyed textile such that the sprayed fluid generates a cone-shaped spray pattern. The dyed textile is conveyed at an angle of between 30° and 60° relative to a substantially vertical axis. Consequently, the fluid being sprayed contacts the dyed textile at an angle between 20° and 70°.
The fluid being sprayed is heated above 60° C. or, more specifically, to approximately 80° C.-90° C. via a heating element 705. The heating element 705 is a trace heater. The fluid is sprayed at approximately 45 l/min. Furthermore, the fluid is sprayed at a pressure of approximately 0.7 bar. The apparatus 700 comprises a pump 710 configured to generate the required fluid flow rate and pressure.
In some embodiments, the fluid applicator 430 is configured to rotate. More specifically, the fluid applicator 430 is configured to rotate up to 360 degrees so that the spray nozzles can be used to clean excess dyestuff from within the chamber 480.
The chamber 480 is partially filled with a fluid. The fluid is a liquid. The fluid comprises any excess fluid sprayed by the fluid applicator 430. More specifically, the fluid is predominantly water. However, any suitable fluid may be used. The fluid collects at the bottom of the chamber 480, as shown in
Excess liquid within the chamber 480 overflows the weir 722 and exits the chamber 480 via the drain 720. The drain 720 comprises a pump 724 configured to pump fluid from the drain back to the fluid reservoir 450. The pump 724 is configured to pump fluid at a rate of 12 l/min. The drain further comprises a filtration unit 455 located between the weir 722 and the fluid reservoir 450. The filtration unit 455 is configured to remove contaminants and particulates from within the fluid.
Moreover, the fluid reservoir 450 is in fluid communication with the chamber 480 via a conduit 736 having a pump 738. The pump 738 is configured to pump liquid from the fluid reservoir 450 into the chamber 480 in order to maintain a predetermined liquid level X. the pump 738 is configured to pump liquid at approximately 10 l/min.
In some embodiments, not shown in
The fluid reservoir 450 is configured to contain up to 10 litres of liquid. The fluid reservoir 450 also comprises gas, such as air. The fluid reservoir 450 is in fluid communication with a bulk fluid source 726 via a pump 728. The pump 728 is a bi-directional pump configured to ensure the fluid reservoir continuously contains 10 litres of liquid. The pump 728 is configured to pump fluid at a rate of 10 l/min.
The chamber 480 comprises a mechanical agitator in the form of two rollers 462, 464. The first roller 462 is located upstream of the fluid applicator 430 and the second roller 464 is located downstream of the fluid applicator 430. The two rollers 462, 464 are configured to reciprocate along a first axis substantially parallel to the movement of the dyed textile between the first and second rollers 462, 464 such that the dyed textile is stretched. Furthermore, the two rollers 462, 464 are configured to reciprocate along a second axis transverse to the movement of the dyed textile between the first and second rollers 462, 464 such that the dyed textile is sheared. These two reciprocating movements agitate the fibres of the dyed textile. Moreover, the movement of the dyed textile is configured to massage applied chemistry, such as softeners or fragrance, into the dyed textile fibres. The reciprocation of the rollers 462, 464 is controlled via a rotating cam 732.
The chamber 480 further comprises a nip roller 766 configured to apply a pressure to the dyed textile as it passes between the nip roller 766 and a second roller, which in this instance, is roller 464. However, in other embodiments not illustrated in
The fluid removal device 440 comprises a tube 770 configured to eject a gas onto the textile. The gas is air. However, any suitable gas may be used. In some embodiments, the gas may comprise a fragrance. The gas is also heated to between 40-100° C. More specifically, the gas is heated to between 60-95° C. or, most specifically, the gas is heated to between 80-90° C. The gas is heated via a plurality of finned heaters 772. The gas is expelled from the tube 770 at a speed between 50-160 m/s. More specifically, the gas is expelled from the tube 770 at a speed between 80-140 m/s or, most specifically, the gas is expelled from the tube 770 at a speed between 100-120 m/s.
The fluid removal device 440 further comprises a collection chamber 773 configured to collect the fluid, comprising liquid and gas, and any solids, including, but not limited to contaminants and excess dye particulates, that pass through or are expelled from the surface of the dyed textile 420 in the vicinity of the tube 770. The collection chamber 773 comprises a knife-edge roller 778 configured to contact the dyed textile 420 in the vicinity of the fluid removal device 440. More specifically, the collection chamber comprises a plurality of knife-edge rollers 778. The knife-edge rollers 778 support the dyed textile 420 in order to minimise the deflection of the dyed textile that is generated as a result of the fluid removal device 440.
The collection chamber 773 is in fluid communication with a separation unit 774 configured to separate gas from liquid and solids. The separation unit 774 comprises a vortex or cyclone configured to collect liquid and solid particles at a first end 775, such as the base, and expelled gas from a second end 776, such as the top. The first end 775 of the separation unit 774 is in fluid communication with the fluid reservoir 450 via a pump 715. The pump 715 is configured to pump the fluid collected at the first end 775 of the separation unit 774 back to the fluid reservoir 450 at a rate of 3 l/min. The second end 776 of the separation unit 774 is in fluid communication with the tube 770 via the plurality of finned heaters 772. The apparatus 700 further comprises a fan 781 configured to generate gas flow within a conduit 782 connecting the tube separation unit 774 to the tube 770.
The dyed textile downstream of the fluid removal device 440 comprises a liquid content of less than 15%, or more specifically, a liquid content between 5-10%.
The chamber 480 further comprises an ioniser 771 configured to ionise the air in the vicinity of the dyed textile adjacent to the fluid removal device 440. This reduces the charge, thus surface tension, of the dyed textile.
This invention is further illustrated by the following examples, which are for illustrative purposes only, and are not intended to limit the invention, as described above. Modifications may be made to the provided examples without departing from the scope of the invention.
The use of a continuous digital dyeing process as described in WO 2020/208362 was employed for the roll-to-roll deposition step in this example. A commercially available dispersive dyestuff was applied to a 100% polyester textile with high precision and control over homogeneity and wet add-on. The digital approach ensures that all deposited dyestuff is required for the target shade, ensuring no wash steps are required to remove excess dyestuff to achieve good colourfastness. The resulting wet loaded textile was passed through an infra-red (IR) fixation chamber to remove carrier water used in the deposition process. The use of IR further enhances the homogeneity of dyestuff across the web width of the textile and ensures limited aggregate formation during whilst the textile is wet.
The resulting roll of dry dyed textile was then then conveyed into the first chamber having a set temperature of 200° C. The line speed was then set as to allow for a 5 minute dwell time for the textile in the first chamber. The heat-treated roll is held in the first chamber to ensure no heat is lost from the roll and cut to a set size of 100m length.
The discrete roll of 100 m was then moved into the second chamber for two hours for additional treatment. To enable the production rate of the fixation unit to be maintained, several rolls are cut and stored in the second chamber in sequence, ensuring each roll is exposed to the same thermal conditions. The roll was then removed and stored for cooling.
Additional diffusion occurs during the cooling step. As a consequence of the low thermal conductivity of the textile the substrate nearest the core will maintain a sufficient temperature to allow for further diffusion enhancement.
The resulting product was of an improved colourfastness whilst the hand feel of the textile was not affected.
The dyestuff deposition method is the same as applied in Example 1.
The resulting roll of dry dyed textile was then conveyed, in a roll-to-roll manner, into the first chamber having a set temperature of 170° C. Moreover, steam was added to the first chamber to create a high humidity environment. The line speed was then set as to allow for an 8 minute dwell time for the textile in the heated steam zone. The treated substrate was then folded loose into an insulated drum and cut to a specific length of 500m. The drum was then heated by an external heat source to 180° C. for 1 hour for additional thermal treatment. The resulting product is of an improved colourfastness whilst the hand feel of the textile is not affected.
The resulting drum of textile can be held in an insulated environment, such as the second chamber, to limit cool down of the textile. This extends the time at temperatures deemed sufficient for thermally enhanced diffusion. The insulated carrier will also be movable to ensure the dyed textile can be moved.
A commercially available dyestuff with high fastness properties and minimal or colourless formulation auxiliaries was applied in the described method using a digital dye method. The exact amount of dyestuff was applied to achieve the target shade and the loaded textile was dried using IR heat. The use of minimal or colourless auxiliaries, such as surfactants or levelling agents can further enhance the wash-less fastness performance with this method.
The dry dyed substrate was then processed for 3 minutes at 220° C. within the fixation chamber. The resultant hot substrate was re-rolled into a consolidated roll within the first chamber to ensure that the textile retains heat, minimising any requisite additional heating to maintain the target temperature. The resulting roll was then moved into the second chamber, where one or more rolls are also incubated and held at a range of temperature steps for varying amounts of time. The specific temperature profile is dyestuff and/or textile specific. However, it will typically take the form of 20° C. steps from 180° C. to 140° C. with typical step times of 20 min. This will be controlled by the second chamber.
The dyestuff deposition method is the same as applied in Example 1.
A commercially available dispersive dyestuff was applied with a high precision and control over homogeneity and wet add on. The digital approach ensures that almost all deposited dyestuff is required for the target shade, ensuring minimal excess unfixed dye remaining on the surface, following drying by IR heat and initial thermal processing of 5 minutes at 200° C. within the fixation chamber
The resultant source material was then processed by exposure to a recirculated fluid flow, a combination of water and silicone softener. The fluid was applied to the textile by spray nozzles at a flow rate of 15 L/min, providing a wet add-on of 150% of the initial source textile weight. The textile was then agitated by the use of textured rollers, as to provide movement between the fibres and expose all excess dye to the fluid. This mechanical agitation process also improved penetration of finishing chemistries. The wet add on was then reduced to 20% using vacuum removal. This process of application, agitation and removal was repeated, as to achieve the optimum results. The resultant high colourfastness textile was then dried to <10% wet add on and the fluid that was removed from the textile by vacuum was continually recovered by filtration and reverse osmosis to yield pure water throughout the duration of the process.
The dye deposition method is the same as applied in Example 1, 2 and 4.
The resulting dyed source material was then processed by exposure to a recirculated fluid bath. The textile was dipped through the fluid bath and a wet add on of 300% of the textile weight was achieved. The wet add on was then reduced to 100 by the use of nip rollers following the bath and mechanical agitation was applied by use of rotating brushes at 5× relative speed to the web line speed, creating agitation within the textile. The fluid was then removed by vacuum, yielding a wet add on of 40%, and the fluid was recovered by filtration and recycled within the fluid system. The resulting textile was dried to completion by heat application.
Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure. “and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example “A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.
Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described. It will further be appreciated by those skilled in the art that although the invention has been described by way of example with reference to several embodiments. It is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2109535.1 | Jul 2021 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2022/051704 | 7/1/2022 | WO |
