Automatic machine laundering of fabrics
First Claim
1. A method of laundering fabrics in an automatic washing machine having a drum, wherein the automatic washing machine is operated so as to cause it to run through at least one wash cycle and at least one rinse cycle, which method comprises:
- (a) during the at least one wash cycle forming in the drum an aqueous washing liquor containing a detersive surfactant component and a detergent builder component, the aqueous wash liquor having pH above about 7;
(b) contacting fabrics to be laundered with the aqueous wash liquor in the drum;
(c) during the rinse cycle, forming in the drum an aqueous rinse liquor and contacting the fabrics with said rinse liquor; and
(d) adding to the rinse liquor sufficient acid source to bring the pH of the rinse liquor into the range of from about 4 to about 7.
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Accused Products
Abstract
The invention provides a method of laundering fabrics in an automatic washing machine having a drum wherein the automatic washing machine is operated so as to cause it to run through at least one wash cycle and at least one rinse cycle. Such a method comprises: (a) during the at least one wash cycle forming in the drum an aqueous washing liquor containing a detersive surfactant component and a detergent builder component, the aqueous wash liquor having pH above about 7; (b) contacting fabrics to be laundered with the aqueous wash liquor in the drum; (c) during the rinse cycle forming in the drum an aqueous rinse liquor and contacting the fabrics with the rinse liquor; (d) adding to the rinse liquor sufficient acid source to bring the pH of the rinse liquor in the range of from about 4 to about 7, preferably from about 4.5 to about 6.5. The use of this lowered pH in the rinse liquor gives a variety of cleaning benefits, and preferably fabric care benefits in combination with rinse additive, in the context of an automatic washing process. The invention also provides particular systems for application of the acid source to the rinse liquor.
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Citations
19 Claims
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1. A method of laundering fabrics in an automatic washing machine having a drum, wherein the automatic washing machine is operated so as to cause it to run through at least one wash cycle and at least one rinse cycle, which method comprises:
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(a) during the at least one wash cycle forming in the drum an aqueous washing liquor containing a detersive surfactant component and a detergent builder component, the aqueous wash liquor having pH above about 7;
(b) contacting fabrics to be laundered with the aqueous wash liquor in the drum;
(c) during the rinse cycle, forming in the drum an aqueous rinse liquor and contacting the fabrics with said rinse liquor; and
(d) adding to the rinse liquor sufficient acid source to bring the pH of the rinse liquor into the range of from about 4 to about 7. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for providing sequential addition of wash additives and rinse additives to the wash and rinse cycles, respectively, of a fabric laundering operation carried out in a drum-containing automatic washing machine, which system comprises:
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(a) a unit dose package comprising at least one compartment containing wash additive material comprising a detersive surfactant component and a detergent builder component, said wash additive material serving to provide aqueous wash liquor having a pH of above about 7; and
at least one additional compartment containing an acid source sufficient to bring the pH of rinse liquor formed during said rinse cycle to a pH of from about 4 to about 7;
(b) a rigid housing structure into which at least the rinse additive compartment(s) of said unit dose package can be inserted at the beginning of the laundering operation, said housing structure being positioned within the drum of said automatic washing machine in a location which brings it into significant contact with wash and rinse water during the laundering operation;
(c) means associated with said wash additive material compartment(s) of the unit dose package to open said wash additive compartment(s) and to thereby release the contents of said wash additive compartment(s) into the aqueous wash liquor in said drum;
(d) means associated with said housing structure or with said rinse additive compartment(s) of said unit dose package or with both to open said rinse additive compartment(s) and to thereby release the rinse additive contents thereof into said housing structure, said rinse additive compartment opening means being activated by centrifugal force applied to said rinse additive compartment(s) during the spin cycle occurring in the operation of said automatic washing machine; and
(e) means for transferring said rinse additive material from said housing structure into the aqueous rinse liquor formed in said washing machine drum during the rinse cycle of said fabric laundering operation. - View Dependent Claims (19)
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Specification