Applications of scCO2 as a “Green” Solvent in the Textile Industry
It is well recognized that the textile industry is one of the world's largest users of potable water. Supercritical CO2 (scCO2) solvent characteristics can allow it to replace water in many textile operations such as scouring and dyeing, thereby significantly reducing or eliminating water demand.
Having built our first commercial scCO2 textile dye system in the 1997, we are again focused on further development and scaling up the use of scCO2 as a solvent in the textile industry.
This paper will focus on the application of scCO2 to the following textile operations and the accompanied reduction in water, energy and chemicals use and waste generated.
Scouring: Nylon and cotton fabrics were scoured using with scCO2 and showed extraction efficiencies > 95%. Scouring of cotton with scCO2 was also comparable to better than conventional water based scouring. The scCO2 scoured fabrics were tested for mechanical properties and for dyeing by conventional means and were found to be acceptable.
Dyeing of fabric and garments : Polyester and nylon yarn, fabric and garments were dyed in scCO2 using raw or non-formulated disperse dyes, and mixtures of raw dyes. The color uptake in the fabric was measured using a Datacolor colorimeter. A novel dye vessel design and process cycle have been developed which allows reproducible and uniform dyeing in a < 2 hour cycle. Commercial scale-up continues.
Dye Recovery : We have demonstrated in a potential new application in which a significant portion of a dye or dye mixture infused into polyester or nylon can be recovered for re-use by extracting with scCO2. This is not possible in the dyeing process practiced today.
Having built our first commercial scCO2 textile dye system in the 1997, we are again focused on further development and scaling up the use of scCO2 as a solvent in the textile industry.
This paper will focus on the application of scCO2 to the following textile operations and the accompanied reduction in water, energy and chemicals use and waste generated.
Scouring: Nylon and cotton fabrics were scoured using with scCO2 and showed extraction efficiencies > 95%. Scouring of cotton with scCO2 was also comparable to better than conventional water based scouring. The scCO2 scoured fabrics were tested for mechanical properties and for dyeing by conventional means and were found to be acceptable.
Dyeing of fabric and garments : Polyester and nylon yarn, fabric and garments were dyed in scCO2 using raw or non-formulated disperse dyes, and mixtures of raw dyes. The color uptake in the fabric was measured using a Datacolor colorimeter. A novel dye vessel design and process cycle have been developed which allows reproducible and uniform dyeing in a < 2 hour cycle. Commercial scale-up continues.
Dye Recovery : We have demonstrated in a potential new application in which a significant portion of a dye or dye mixture infused into polyester or nylon can be recovered for re-use by extracting with scCO2. This is not possible in the dyeing process practiced today.
