Sustainable dyeing of cellulosic fabrics in textile mills

Abstract

A textile mill (100) includes a testing and recipe finalization station (104), pretreatment application machinery (106), dye application machinery (114), and a post-dye processing station (124). An associated process involves applying a pretreatment to the cellulosic fabric for cationizing the cellulosic fabric and applying a dye treatment to the cellulosic fabric. A recipe for the dyeing process includes a predetermined concentration of a cationizing agent of the pretreatment based at least in part on a desired concentration of the dyeing component. A two-stage drying and curing process for the pretreatment and other processing equipment and parameters are also described that ensure a high-quality dyeing process with reduced environmental impacts.

What is claimed: 
     
         1 . A method for use in dyeing cellulosic fabric, comprising:
 establishing a dyeing process for said cellulosic fabric including applying a pretreatment to said cellulosic fabric for cationizing said cellulosic fabric, said pretreatment including a cationizing agent, and applying a dye treatment to said cellulosic fabric, said dye treatment including a dye component;   selecting a nominal recipe for said dyeing process including a predetermined concentration of said cationizing agent based at least in part on a desired concentration of said dye component to be applied to said cellulosic fabric;   first providing said pretreatment in accordance with said nominal recipe;   first applying said pretreatment to said cellulosic fabric;   second providing said dye treatment; and   second applying said dye treatment to said cellulosic fabric.   
     
     
         2 . The method of  claim 1 , wherein said selecting comprises determining said nominal recipe based at least in part on a material of said cellulosic fabric. 
     
     
         3 . The method of  claim 2 , wherein said selecting comprises determining said nominal recipe based at least in part on a cotton content of said material. 
     
     
         4 . The method of  claim 1 , wherein said selecting comprises determining said nominal recipe based at least in part on a wet pick-up of said cellulosic fabric. 
     
     
         5 . The method of  claim 4 , wherein said wet pick-up is determined for the cellulosic fabric and for equipment to be used in applying said pretreatment in production by obtaining a sample piece of said cellulosic fabric, obtaining a preprocessing weight for said sample piece, applying said pretreatment to said sample piece, processing said sample piece in said equipment, obtaining a postprocessing weight of said sample piece, and using said preprocessing and postprocessing weights to obtain a wet pick-up value. 
     
     
         6 . The method of  claim 1 , wherein said selecting comprises determining a concentration of said cationizing agent based on a desired concentration of said dye component and a wet pick-up of said cellulosic fabric. 
     
     
         7 . The method of  claim 1 , wherein said nominal recipe further includes a cross-linking agent and a thermal initiator. 
     
     
         8 . The method of  claim 7 , wherein said cross-linking agent is tetra(ethylene glycol) diacrylate (TEGDA). 
     
     
         9 . The method of  claim 7 , wherein said thermal initiator is sodium persulfate. 
     
     
         10 . The method of  claim 1 , wherein said nominal recipe has a higher ratio of the predetermined concentration of said cationizing agent to said desired concentration of said dye component at a higher desired dye concentration of said dye component than at a lower desired dye concentration of said dye component. 
     
     
         11 . The method of  claim 10 , wherein said ratio is about 2.0 for said higher desired dye concentration and is less than 2.0 for said lower desired dye concentration. 
     
     
         12 . The method of  claim 11 , wherein said higher desired dye concentration is 5%. 
     
     
         13 . The method of  claim 1 , wherein said step of first providing comprises forming a mixture of water, said cationizing agent, a cross-linking agent, a thermal initiator, and at least one additional component. 
     
     
         14 . The method of  claim 13 , where said step of first providing comprises providing a first mixture of said cationizing agent and said cross-linking agent, adding said thermal initiator to said first mixture to provide a second mixture, and adding said at least one additional component after forming said second mixture. 
     
     
         15 . A fabric manufactured by the process of  any of the preceding claims . 
     
     
         16 . A textile product manufactured by the process of  any of the preceding claims . 
     
     
         17 . A method for use in processing a textile product, comprising:
 providing a base fabric;   first applying a pretreatment to said base fabric, said pretreatment effective to reduce an environmental impact associated with dyeing said base fabric;   second applying a dye to said base fabric;   processing said base fabric to ensure even distribution of said dye across said base fabric;   transporting said base fabric to a drying machine; and   drying said base fabric, at said drying machine having a fabric drying interface, using a two-stage drying process including a first stage where a first drying airflow is provided to said base fabric via one or more first ports extending continuously across a majority of a width of said fabric drying interface, and a second stage where a second drying airflow is provided to said base fabric via one or more second ports, each said second port extending across only a minority of a width of said fabric drying interface.   
     
     
         18 . The method of  claim 17 , wherein said base fabric is a cellulosic fabric. 
     
     
         19 . The method of  claim 17 , wherein said base fabric comprises, at least in part, cotton. 
     
     
         20 . The method of  claim 17 , wherein said pretreatment comprises a cationizing agent. 
     
     
         21 . The method of  claim 20 , wherein said pretreatment further comprises a cross-linking agent and a thermal initiator. 
     
     
         22 . The method of  claim 17 , wherein at least one of said first applying and second applying comprises passing said base fabric through a liquid bath. 
     
     
         23 . The method of  claim 17 , wherein said processing comprises passing said base fabric between opposing rollers. 
     
     
         24 . The method of  claim 17 , wherein said transporting comprises delivering said base fabric to said drying machine at a speed that matches a fabric speed of said drying machine. 
     
     
         25 . The method of  claim 17 , wherein said drying machine has a fabric drive for moving said base fabric in a first direction through said drying machine and said width of said fabric drying interface is measured in a second direction transverse to said first direction. 
     
     
         26 . The method of  claim 25 , wherein said one or more first ports comprise a vent having a longitudinal axis extending in said second direction. 
     
     
         27 . The method of  claim 26 , wherein said one or more second ports comprise a circular vent. 
     
     
         28 . A textile product produced using the method of any of  claims 17-27 . 
     
     
         29 . A drying machine for drying a dyed textile product produced by applying a pretreatment to a base fabric for reducing an environmental impact of dyeing said base fabric and applying a dye to said base fabric, said drying machine comprising:
 a first stage where a first drying airflow is provided via one or more first ports, each said first port extending continuously across a majority of a width of a fabric drying interface of said drying machine;   a second stage where a second drying airflow is provided via one or more second ports, each said second port extending across only a minority of a width of said fabric drying interface; and   a fabric drive for moving said base fabric in a first direction through said drying machine between said first stage and said second stage, wherein said width of said fabric drying interface is measured in a second direction transverse to said first direction.   
     
     
         30 . The drying machine of  claim 29 , wherein said one or more first ports comprise a vent having a longitudinal axis extending in said second direction. 
     
     
         31 . The drying machine of  claim 30 , wherein said one or more second ports comprise acircular vent.