Machine Dishwashing

Since nearly all products for washing and dishwashing are complex mixtures of different ingredients, an in-situ access to the relevant data is of high interest This can be achieved by using on-line sensors in the specific applications. Washing and dishwashing machines equipped with on-line sensors will be discussed as an... 

Applications focus on turbidity, conductivity, water hardness, mass, and concentration, which are measured in automatic washing and dishwashing machines. 

The turbidity level or more exactly the optical transmittance and reflectance provides a range of information about the washing and rinsing water in automatic washing and dishwashing machines. The most important parameters are soil and detergent concentration, both of which have an impact on turbidity. 

Phosphonates are surface-active chelants and are widely used in industry for scale and corrosion control, and in cleaning agents, dispersants, and other applications. The annual sales of phosphonates in the U S A amount to over two billion dollars per year [8]. Phosphonates inhibit calcium scale formation by interfering with the crystal structure of calcium salts, making the crystals softer so that they are more easily removed by washing - the threshold effect [9]. A key application is controlling scale particularly in hard-to-reach places such as laundry and dishwashing machines. 

Liquid formulations have since been introduced as well and often contain a bentonite-based clay substance to prevent the liquid product from seeping out of a standard automatic dishwashing machine powder dispenser. 

U.S. 6448212 07/2000 Holderbaum et al.l Henkel KgaA Laundry detergent portion for use in a washing/dishwashing machine for a program taking place in an aqueous phase... 

The concept of using mechanical devices for dishwashing was documented as early as 1865 with the issuance of a U.S. Patent to J. Houghton [1], Subsequently several companies tried to manufacture and market automatic dishwashing machines for home as well as for institutional use [2,3], However, it was not until the early 1950s that both detergents and mechanical dishwashers became widely available to consumers. By the early 1990s, an estimated 50% of the households in the U.S., 25% in Europe, and 8% in Japan had automatic dishwashers [4],... 

FIG. 9.1 Stainless steel inside of an automatic dishwashing machine. (Courtesy of the General Electric Co.)... 

Essential to the development of new LADD products is the evaluation of their performance. It is important that the test conditions closely reproduce the conditions encountered by the consumer under typical household situations therefore, prototype formulas are usually tested in actual dishwashing machines using real food soils. 

Application method Automatic dishwashing machine Manufacture Ribbon or paddle blender... 

The hand dishwash liquid market has remained static for a number of years. This is due to an increase in the use of dishwasher machines, which will eventually cause a decline in the manual products. Ethanol is present at low levels in many hand dishwash products. Machine dishwasher products are mainly powder detergents. The machines also used a rinse aid which contains a short chain alcohol, usually isopropanol. 

The polycarboxylate builders inhibit the growth of inorganic crystals, which would be formed in their absence during the washing process when phosphate-free or low-phosphate detergents are used. Another function of the polycarboxylates is their ability to disperse soil as well as prevent redeposition of the soil and minimize incrustations of insoluble salts on the fabric. Polycarboxylates are also used as dispersants and to provide shine in formulations for automatic dishwashing machines. 

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