Patent ID: 8809249

Claim:
A method of removing scale during a wash cycle, the method comprising: diluting a detergent concentrate to form a detergent use solution, the detergent concentrate comprising an alkalinity source constituting between about 1% and about 75% by weight of the detergent concentrate; a surfactant system constituting between about 0.05% and about 25% by weight of the detergent concentrate; and a threshold system constituting between about 0.0005% and about 30% by weight of the detergent concentrate; wherein the threshold system comprises a sulfonate/acrylate copolymer, an acrylate homopolymer and a phosphonoalkane carboxylic acid and wherein the phosphonoalkane carboxylic acid constitutes between about 5% to about 30% by weight of the threshold system, wherein the threshold system has a sulfonate/acrylate copolymer to acrylate homopolymer weight ratio of between about 2:1 and about 1:2 and has an acrylate homopolymer to phosphonoalkane carboxylic acid weight ratio between about 4:1 and 1:1; and wherein the detergent concentrate has a pH of at least about 10; and contacting a substrate with the detergent use solution.