Process for the production of detergent tablets for dishwashing machines

Claim 1

The process of producing a stable, dual-function, phosphate- and metasilicate-free, low-alkaline detergent tablet for dishwashing machines comprising: a) agglomerating a homogeneous, spray-dried granular alkaline detergent additive with builders, nonionic surfactants and water to form an agglomerate, said additive comprising (1) 35 to 60% by weight of sodium salts of at least one homopolymeric or copolymeric (meth) acrylic acid, (2) 35 to 50% by weight of anhydrous sodium carbonate, (3) 4 to 20% by weight of anhydrous sodium sulfate, and (4) 1 to 7% by weight of water, all weights being based on the weight of said granular detergent additive, b) treating said agglomerate with hot air in a fluidized bed, c) mixing said agglomerate with a bleaching agent, and d) tabletting said agglomerate and bleaching agent mixture to provide a tablet containing 5 to 30% by weight of said granular detergent additive 5 to 40% by weight of trisodium citrate dihydrate, 5 to 60% by weight of anhydrous sodium carbonate, 3 to 15% by weight of bleaching agent, and 3 to 15% by weight of water, wherein said tablet has a broad dissolving profile whereby at least 10 to 40% by weight of said tablet is dissolved in cold water flowing into a dishwashing machine during the prerinse cycle and at least 60 to 90% by weight of said tablet is available for the main dishwashing cycle.