Patent ID: 7479165

Claim:
A method of enhancing removal of dirty motor oil from polyester/cotton which method comprises washing a laundry fabric comprising said polyester/cotton in a wash liquor in a washing machine, said wash liquor containing surfactant material, wherein during a single wash cycle no more than 10% by weight of the wash liquor is drained from the washing machine, wherein the concentration of the surfactant material in the wash liquor is substantially constant during the wash cycle, and wherein said method comprises the step of changing the ionic strength of the wash liquor by addition of one or more ionic ingredients thereto during the wash cycle; wherein the wash cycle comprises at least a first phase and a second phase, and wherein the ionic strength of the wash liquor is higher during the second phase than the first phase; wherein either or both phases have a duration of from 2 to 60 minutes; wherein during at least part of said first phase, the ionic strength of the wash liquor is from 0.001 to 0.06 M and during the second phase the ionic strength of the wash liquor is from 0.01 to 0.5 M; wherein addition of ingredients to change ionic strength and reach the second phase is effected (1) by dosing from a dosing device attached to the machine or (2) by cycling at least part of the wash liquor through an external dosing device and back into the machine; wherein during at least 50% of the time of variation of the ionic strength, the wash liquor has a temperature of from 5° C. to 60° C. and wherein the ionic ingredient comprises sodium, potassium or ammonium chloride salt.