The Effect of Wash Temperature on Removal of Particulate and Oily Soil from Fabrics of Varying Fiber Content

Abstract

In the laundry process relatively high wash temperatures have traditionally been used for optimum soil removal. The use of lower wash temperatures could result in a substantial reduction in the amount of energy used in laundering. One of the purposes of this study was to determine soil removal at a range of wash temperatures with detergents of different formulations from cotton, polyester, and cotton/polyester fabrics. A second purpose was to evaluate the use of x-ray fluorescence analysis as a quantitative measure for determining particulate soil removal from fabrics. The samples were soiled by application of clay and either unlabeled or doubly-labeled synthetic sebum. Removal of oily soil was determined by measuring the radioactivity of the samples. Clay removal was measured by x-tay fluorescence analyses of iron and silicon, and overall soil removal was measured by changes in reflectance. Both clay and oily soil appeared to be best removed from cotton fabrics by higher wash temperatures. Low wash temperatures were best in removing the nonpolar fraction (triolein) of oily soil from polyester. Use of phosphate-built anionic detergents generally resulted in better soil removal than other types, regardless of wash temperature. Wash temperatures as low as 10°C gave acceptable soil-removal levels. Iron content varied with clay-particle size, thus silicon was the preferred indicator of clay content of fabrics.

Soil Remaining on Fabrics after Laundering as Evaluated by Response Surface Methodology

“…These polar components were much more easily removed from the cotton and polyester fabrics than was the nonpolar triolein, agreeing with previous research [3,4,9,13,16,17]. The removal of both polar and nonpolar components was similar for the acrylic and nylon fabrics.…”

“…The inverse relationship between wash temperature and removal of the nonpolar triolein from polyester is visible in the response surface plots. This relationship has been previously noted [3,4,9]. Fort et al [3] found evidence of slight diffusion of tristearin into polyester films at high temperatures; however, Obendorf el at.…”

“…components of the oily soil remaining on the samples were made as previously described [9] and are reported as a percentage of the total amount of radioactivity applied.…”

Aging of oily soils on textile materials: A literature review

“…Soap formation due to the presence of fatty acids aids removal of other oily soils as well. Several studies (1,39,41,42) have reported that residual oily soil contains a greater percentage of nonpolar components than fresh oily soil. Polar soils tend to be more easily removed in aqueous detergent systems.…”

Laundry Detergency of Solid Nonparticulate Soil or Waxy Solids: Part II. Effect of the Surfactant Type

“…Moreover, sodium lauryl sulfate (anionic surfactant) was the best candidate for fatty soil removal from the cellulose whereas nonylphenyl polyethylene glycol (nonionic surfactant) was the best for the polyethylene terephthalate (hydrophobic surface). Morris and Prato () found that the removal of both particulate and oily soils from cotton fabric increased with an increase in washing temperature whereas for a nonpolar–oily–soil on the polyester surface, the removal increased with decreasing washing temperature. Illman et al () and Spangler et al () found similar results for sebum removal from dacron, nylon, or polyester; i.e.…”