Aging of oily soils on textile materials: A literature review

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.

Section: Relationship Between the Removal Rate And Composition Of Thesupporting

confidence: 83%

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

Yamada

Tsutsui

Natsuhara

et al. 2007

“…On the basis of these findings, the organic acids, which are dominant odorants in axillary sweat (3), were believed to have only a minor impact on the overall odor impression of washed swatches. In general, the polarity of soils affects the adhesion of the soil onto textile fibers, interaction with the detergent, and the water/soil interfacial energy (4). Under wash at high pH (pH > 9), acids are found in their polar, dissociated form.…”

Section: Resultsmentioning

confidence: 99%

“…Three major glandular systems supply chemicals to the skin surface; the sebaceous, eccrine, and apocrine glands (2,3). Sebum, the sebaceous secretion of the skin, consists of a complex mixture of wax esters, cholesteryl esters, cholesterol and other sterols, squalene, hydrocarbons, and triglycerides that, upon hydrolysis by bacterial and skin lipases, gives mono-and diglycerides and free fatty acids (4). Mono-, di-, and triglycerides and free fatty acids constitute approximately 60% of the human skin surface lipid composition by weight (5).…”

mentioning

confidence: 99%

Primary odorants of laundry soiled with sweat/sebum: Influence of lipase on the odor profile

Munk

Münch

Stahnke

et al. 2000

Odorants still attached to laundry soiled with human axillary sweat and sebum after a mild washing procedure [European full-scale, short-cycle wash (20 min wash, 15 min rinse) at 30°C, using color detergent at 3.5 g/L] were extracted and analyzed by aroma extract dilution analysis. Esters (ethyl-2-methylpropanoate and ethylbutanoate), ketones (1-hexen-3-one and 1-octen-3-one) and, in particular, aldehydes [(Z)-4-heptenal, octanal, (E)-2-octenal, methional, (Z)-2-nonenal, (E,Z)-2,6-nonadienal, (E,Z)-2,4-nonadienal, (E,E)-2,4-decadienal, and 4-methoxybenzaldehyde] were identified as primary odorants. Organic acids, which are dominant characteristic odorants in human axillary sweat, were, on the other hand, effectively removed during the washing process. The influence of lipase activity on the odor profile was investigated by analyzing selected sets of textile swatches, sampled from the right/left axillary of male runners, washed in the presence or absence of lipase. The swatches were examined by a sensory ranking analysis prior to the analytical odor analysis. Swatches selected for the subsequent odor analysis possessed greater odor intensity when washed in the presence of lipase than the corresponding swatches washed in the absence of lipase. The aroma extract dilution analysis revealed that aldehydes were present in slightly greater concentrations in swatches washed in the presence of lipase. The aldehydes are believed to be formed through oxidative degradation of triglycerides present in human sebum, which may be facilitated by lipase. Based on sensory panel results and dilution analysis of odorants, the impact of lipase on the odor impression was, however, minor and thus believed to be inadequate as explanation for malodor generation in laundry as experienced by the consumer.

“…We previously reviewed the research literature on the effect of aging on oily soils (1). Oxidation undoubtedly takes place when oily soils are aged on textile materials.…”

mentioning

confidence: 99%

Aging of oily soils on textiles. Chemical changes upon oxidation and interaction with textile fibers

Chi

Obendorf

1998

Self Cite

Aging of unsaturated oily soils on textile materials produces yellow compounds that are difficult to remove by washing. To investigate changes that occur in oily soils when aged, the aging of squalene and artificial sebum were studied. Proton nuclear magnetic resonance, infrared spectroscopy, gas chromatography, and gel permeation chromatography studies showed that oily soils were oxidized upon aging, forming low molecular weight products that also polymerized to higher molecular weight compounds with prolonged aging. The oxidation products contained hydroxyl, carbonyl, or ester groups. Oxidation compounds with yellow chromophores appeared to be mostly those of the 1000-2500 molecular weight fraction; though in earlier stages of aging, lower molecular weight fractions also contained chromophores. By using glucose as a model compound of cellulose, it was found that yellow oxidation products of aged squalene were covalently bound to the substrate. Because the aging of oily soils is a free-radical oxidation process, oxidation products having chromophores are thought to attach to the cotton substrate through radical coupling. Oily soils also showed possibilities of chemical bonding with nylon but not with polyester. JSD 3, 371-380 (1998).