Oily Grime Formed on Hard Surfaces of Kitchen Appliances: (Part 2) Kinetics of Oily Grime Removal

Abstract

The oily grime adsorbed to the surfaces of kitchen appliances ages to become difficult to remove using normal dishwashing detergents. Artificial grime models similar to actual grime were prepared using composition data of the oily grime obtained in previous work. To evaluate typical cleaning products, one needs to observe their efficacy against actual and artificial grime using precise and objective evaluation methods. In the present work, the kinetic method was applied to actual kitchen grime. The grime-removal rate constants were calculated by monitoring absorbance of the cleaning fluids, and the results are discussed based on the compositions of the detergents and grime. One commercial detergent, with pH adjusted to 9.7, consisted mainly of spirit solvent and had two rate constants, k 1 (fast) and k 2 (slow), which indicated the removal rates of THF-soluble and THF-insoluble oily grime, respectively. With a second commercial detergent that contained mainly an alkali agent at pH 11.8, the removal rates were extremely fast for both THF-soluble and THF-insoluble grime. The alkalinity worked effectively against both types of grime. The effects on the removal rates of various ingredients that could be added to the cleaning products were also investigated and the overall removal rates were highly dependent on the pH of the fluids and slightly dependent on the kinds of alkalies used. The present kinetic method was found to be useful for evaluating the capability of the detergents. The plural rate constants observed for a single grime sample, which previously were not well understood, could be interpreted in terms of the compositions of the grime.

Dirt and Grime in Bathrooms: Their Chemical Composition and the Origin of the Triacylglycerols Contained Therein

“…In earlier reports we noted that the oily grime generated on fans and filters in household kitchens consisted of triacylglycerols and their derivatives, and they came entirely from cooking oils [10,11]. Cooking oils were detected even in living spaces away from the kitchen, especially in households where the living spaces were open plan, and those cooking oils interfere with analyses of the relatively small quantity of coexisting human sebum.…”

Performance Improvement of Cleaning Formulations for the Exterior Surface of High‐Speed Trains

“…Effects can be achieved by adding organic solvents into surfactant aqueous solutions: improving the storage stability of cleaners and increasing the ability of cleaners to dissolve oily soils. When the pH value of the solutions is not high enough, the effects of solvents become more obvious (Yamada et al, 2007). Hydrotropes, such as alkylbenzene sulfonates and alkylnaphthalene sulfonates, are short‐chain organic compounds with polar groups that could serve as agents to dissolve poorly water‐soluble substances into water (Burns, 1999), which is reflected in increasing the cloud point of nonionic surfactants and improving the transparency of detergents at operating temperatures.…”