Supercritical fluid material scouring

Abstract

Supercritical fluid (“SCF”) is used to scour a target material to leave scour elements, such as oligomers and oils from the target material. Carbon dioxide (“CO2”) is introduced into a pressure vessel also containing the target material to be scoured. The CO2 is raised in temperature and pressure to a SCF state. The CO2 is recirculated within the pressure vessel to scour the target material. An exchange of the CO2 is occurs allowing for the scoured elements to be removed from the CO2 and therefore from within the pressure vessel. Operation variables such as temperature, pressure, time, internal flow rate, and CO2 exchange are adjusted to achieve a scouring of the target material.

What is claimed is: 
     
         1 . A method of scouring and finishing a target material with supercritical fluid (“SCF”), the method comprising:
 positioning a target material in a pressure vessel; 
 initiating a pressurization cycle of a scouring process in the pressure vessel; 
 initiating a scouring cycle of the scouring process in the pressure vessel; 
 initiating a depressurization cycle of the scouring process in the pressure vessel; 
 introducing a finishing material into the pressure vessel; 
 initiating a pressurization cycle of a dyeing process in the pressure vessel; 
 initiating a dyeing cycle of the dyeing process in the pressure vessel; and 
 initiating a depressurization cycle of the dyeing process in the pressure vessel. 
 
     
     
         2 . The method of  claim 1 , wherein the target material is not removed from the pressure vessel between the initiating of the depressurization cycle of the scouring process and the initiating the pressurization cycle of the dyeing process. 
     
     
         3 . The method of  claim 1 , wherein at least a portion of carbon dioxide used in the scouring process is also used in the dyeing process. 
     
     
         4 . The method of  claim 1 , wherein a flow rate within the pressure vessel is maintained at a non-zero value during the scouring cycle and during the depressurization cycle of the scouring process. 
     
     
         5 . The method of  claim 4 , wherein the flow rate is in a range of 175-240 m 3 /hr during the scouring cycle of the scouring process. 
     
     
         6 . The method of  claim 4 , wherein the flow rate is in a range of 90-130 m 3 /hr during the depressurization cycle of the scouring process. 
     
     
         7 . The method of  claim 1 , wherein a temperature in the pressure vessel is maintained above a threshold value during the depressurization cycle of the scouring process. 
     
     
         8 . The method of  claim 7 , wherein the threshold value is 100 Celsius. 
     
     
         9 . The method of  claim 1 , wherein the target material is a rolled material or a spooled material. 
     
     
         10 . The method of  claim 1 , wherein the target material is a polyester material. 
     
     
         11 . The method of  claim 1 , wherein the scouring cycle of the scouring process removes scoured elements from the target material using SCF carbon dioxide (“CO 2 ”). 
     
     
         12 . The method of  claim 11 , wherein the scoured elements comprise at least one of oligomers or oils. 
     
     
         13 . The method of  claim 12  further comprising adding a surfactant to aid in the bonding between the SCF CO 2  and the at least on one of oligomers or oils. 
     
     
         14 . The method of  claim 11 , wherein at least a portion of the CO 2  from the pressure vessel is exchanged during the scouring process. 
     
     
         15 . The method of  claim 14 , wherein the CO 2  is filtered as the CO 2  is exchanged to separate at least a portion of the scoured elements from the CO 2 .