PARTS-WASHING METHOD
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 A parts-washing method as claimed in claim 1 , wherein the intermediate aqueous phase that is withdrawn and optionally filtered is substantially transparent.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.