>Mechanical energy of the machine itself is responsible for 85% of the soil removal during the cleaning cycle; the detergent contributes the other 15%. Thermal energy is in a sense a secondary effect, contributing to the effectiveness of both the mechanical and chemical components of cleaning.
(From “Liquid Detergents, 2nd Edition”.)
>The primary role of pre-wash is to quickly and mechanically scrape off already loose particles and to dilute pigments before a hot main wash cycle. Already loose particles are a nuisance worth quickly clearing, and pigments can transfer to plastics at some typical wash temperatures, so pre-wash has some value. Tomato sauces (and turmeric) are insidious in this regard. Because I think this latter point might be novel, I’ll quote Whirlpool:
>Pink/orange discoloration of plastics is usually caused by carotenoid, a class of typically red/orange pigments found in foods such as tomatoes and turmeric. When carotenoids are dissolved in oils, they become easily absorbed into many plastics, mainly when heat is also applied. Because the resulting stain is absorbed into the plastic, water-based bleaches are ineffective.
>Pre-rinsing or using a Rinse Hold cycle will reduce the chance of staining. Regular use of a rinse cycle and an air-dry or energy-saving dry option will >reduce the likelihood of staining.
hence, running tap to get hot water into machine is actually counterproductive. dishwasher manufacturers know what they do when they run pre-wash with cold water
>Mechanical energy of the machine itself is responsible for 85% of the soil removal during the cleaning cycle; the detergent contributes the other 15%. Thermal energy is in a sense a secondary effect, contributing to the effectiveness of both the mechanical and chemical components of cleaning.
(From “Liquid Detergents, 2nd Edition”.)
>The primary role of pre-wash is to quickly and mechanically scrape off already loose particles and to dilute pigments before a hot main wash cycle. Already loose particles are a nuisance worth quickly clearing, and pigments can transfer to plastics at some typical wash temperatures, so pre-wash has some value. Tomato sauces (and turmeric) are insidious in this regard. Because I think this latter point might be novel, I’ll quote Whirlpool:
>Pink/orange discoloration of plastics is usually caused by carotenoid, a class of typically red/orange pigments found in foods such as tomatoes and turmeric. When carotenoids are dissolved in oils, they become easily absorbed into many plastics, mainly when heat is also applied. Because the resulting stain is absorbed into the plastic, water-based bleaches are ineffective.
>Pre-rinsing or using a Rinse Hold cycle will reduce the chance of staining. Regular use of a rinse cycle and an air-dry or energy-saving dry option will >reduce the likelihood of staining.
(From https://producthelp.whirlpool.com/Dishwashers/Dishwasher/Was...)
hence, running tap to get hot water into machine is actually counterproductive. dishwasher manufacturers know what they do when they run pre-wash with cold water