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Principles of performance testing of laundry detergents
Author(s) -
Vaughn Thomas H.,
Suter H. F.
Publication year - 1950
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02634900
Subject(s) - laundry , reproducibility , dispersion (optics) , test method , pulp and paper industry , carbon black , environmental science , process engineering , computer science , materials science , mathematics , chromatography , composite material , chemistry , engineering , waste management , optics , statistics , physics , natural rubber
Summary Laboratory performance tests for laundry detergents can fill important needs in laboratory development programs and in control testing, in which cases full scale practical testing is inapplicable. It has been found to be unnecessary and undesirable to attempt close simulation of practice conditions. In order to be most useful to the experimental investigator or the manufacturer of detergents the soil removal and whiteness retention properties should be measured by separate tests. A soil removal test has been devised in which the soil, which consists essentially of carbon black, is applied to the test fabric from aqueous medium. Soiling from aqueous medium has advantages with respect to reproducibility in tenacity and in variation and susceptibility to removal by detergents having different degrees of effectiveness. The quantity of soil removed is measured directly by means of light transmission measurements on the soiled detergent solution. This eliminates uncertainties and limitations inherent in the reflectance method and permits the use of high soil loads in the test cloth, which minimizes redeposition effects. Multiple wash tests are not required. The whiteness retention property is determined by agitating unsoiled swatches in the detergent solution containing carbon black dispersion and measuring the reflectance change of the swatches. The results of both tests are expressed in relative terms, reference detergents being used as controls. The precision of the soil removal tests is approximately ±3.4% in terms of mean deviation and that of the whiteness retention test approximately ±5.1%. Both tests have been used over a period of several years for research and control purposes and have been successfully correlated with actual results in commercial laundries.