Parts-washing method

Abstract

A parts-washing method is described. The method comprises: (a) contacting a part with an aqueous liquid cleaning composition in a contact zone at a temperature of less than 45 degrees C., wherein the aqueous liquid cleaning composition comprises at least one alkoxylate surfactant; (b) passing at least part of the aqueous liquid cleaning composition from the contact zone to a separation housing; (c) separating the aqueous liquid cleaning composition in the separation housing to form an upper oily phase, an intermediate aqueous phase and a lower particulate phase; and (d) withdrawing at least a portion of the intermediate aqueous phase for use as the aqueous liquid cleaning composition in the contact zone.

1 . A parts-washing method comprising:
 a) contacting a part with an aqueous liquid cleaning composition in a contact zone at a temperature of less than 45 degrees C., wherein the aqueous liquid cleaning composition comprises at least one alkoxylate surfactant;   b) passing at least part of the aqueous liquid cleaning composition from the contact zone to a separation housing;   c) separating the aqueous liquid cleaning composition in the separation housing to form an upper oily phase, an intermediate aqueous phase and a lower particulate phase; and   d) withdrawing at least a portion of the intermediate aqueous phase for use as the aqueous liquid cleaning composition in the contact zone.   
     
     
         2 . A parts-washing method as claimed in  claim 1 , wherein the separation housing comprises a base portion and an outlet, said base portion being configured to facilitate withdrawal of the lower particulate phase through the outlet. 
     
     
         3 . A parts-washing method as claimed in  claim 1 , which further comprises withdrawing the lower particulate phase for disposal. 
     
     
         4 . A parts-washing method as claimed in  claim 1 , wherein the portion of the intermediate aqueous phase is filtered prior to use as the aqueous liquid cleaning composition in the contact zone. 
     
     
         5 . A parts-washing method as claimed in  claim 1 , wherein the intermediate aqueous phase that is withdrawn and optionally filtered is substantially transparent. 
     
     
         6 . A parts-washing method as claimed in  claim 1 , wherein the separation housing comprises a further outlet positioned to allow withdrawal of the intermediate aqueous phase for use as the aqueous liquid cleaning composition in the contact zone. 
     
     
         7 . A parts-washing method as claimed in  claim 6 , wherein a filter is positioned in or adjacent the further outlet. 
     
     
         8 . A parts-washing method as claimed in  claim 1 , wherein the aqueous liquid cleaning composition is delivered onto the part using a nozzle. 
     
     
         9 . A parts-washing method as claimed in  claim 8 , wherein the aqueous liquid cleaning composition is delivered onto the part at high pressure. 
     
     
         10 . A parts-washing method as claimed in  claim 8 , wherein the aqueous liquid composition is delivered as a foam. 
     
     
         11 . A parts-washing method as claimed in  claim 1 , wherein the contact zone comprises a soaking bath. 
     
     
         12 . A parts-washing method as claimed in  claim 11 , wherein the part and aqueous liquid cleaning composition are introduced into the soaking bath and ultrasonic waves are propagated through the aqueous liquid cleaning composition in the soaking bath. 
     
     
         13 . A parts-washing method as claimed in  claim 11 , wherein the part and aqueous liquid cleaning composition are introduced into the soaking bath and the aqueous liquid composition is mechanically agitated. 
     
     
         14 . A parts-washing method as claimed in  claim 1 , wherein the aqueous liquid cleaning composition comprises at least two ethoxylated surfactants. 
     
     
         15 . A parts-washing method as claimed in  claim 14 , wherein the aqueous liquid cleaning composition additionally comprises an anionic surfactant. 
     
     
         16 . A parts-washing method as claimed in  claim 1 , wherein the part is contacted with the aqueous liquid cleaning composition in the contact zone at a temperature of 10 to 35 degrees C. 
     
     
         17 . A parts-washing method as claimed in  claim 1 , wherein the separation step is carried out at a temperature of 10 to 35 degrees C. 
     
     
         18 . A parts-washing method as claimed in  claim 1 , wherein the part comprises a metal part. 
     
     
         19 . A parts-washing method as claimed in  claim 1 , wherein steps a) to d) are repeated for a plurality of cycles. 
     
     
         20 . A parts-washing method as claimed in  claim 19 , wherein, once steps a) to d) are repeated for a plurality of cycles, the separation housing is emptied and re-filled with a fresh source of the aqueous liquid cleaning composition before steps a) to d) repeated for a further plurality of cycles. 
     
     
         21 . A parts-washing method as claimed in  claim 1 , wherein the aqueous cleaning composition is contacted with the part in the contact zone at the ambient temperature of the surroundings. 
     
     
         22 . A parts-washing method as claimed in  claim 1 , wherein the aqueous cleaning composition is not heated prior to contact with the part in the contact zone.