A double label radiotracer approach to detergency studies

Abstract

The comparative detergency of a series of built detergents of commercial interest has been measured via the use of a doubly labeled multicomponent synthetic soil. Four test fabrics: cotton, nylon, Dacron, and Dacron/cotton were soiled with the seven-component soil, which was in turn almost completely and then individually labeled. The fabrics were washed in a conventional Tergotometer under cold-water and hotwater conditions. Analyses of the fabrics before and after washing were made by liquid scintillation counting.Two sets of experiments were run, the first based on cold-water detergent formulation (heavy-duty liquid), the second based on hotwater detergent formulation (heavy-duty powder). A number of nonionic surfactants were compared with linear alkyl aryt sulfonate in the first set, and two anionics were compared with two nonionies in the second set.Expressing results as total detergency, i.e., amount of soil removed from all four fabrics, it.was found that, under cold-water conditions, LAS (average side chain Cls) is significantly less effective than the nonionics investigated. The linear primary alcohol (C12-C~ and C14-C15) ethoxylates removed slightly more soil than the ethoxylates of a Ziegler alcohol (C14, C16, Cls) and random secondary alcohols (Cll-C1.~). The same tabulation for the heavy-duty powder formulations under hot-water conditions showed LAS to be least effective over-all, sulfated linear primary alcohol somewhat more effective, and ethoxylated linear, primary alcohol slightly more effective still.Redeposition of the various soil components onto unsoiled cotton was found to be slight, ranging from 0.2% to 1.7% of the amount in the wash water.

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.…”

“…In woven cotton fabrics, the formation of neps has been attributed to fiber properties such as immaturity, staple length, fineness and moisture content [3,4] and to handling methods in production such as over or under beating the fibers in the carding or ginning op-…”

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.…”

“…In contrast to fatty acids, triglycerides are generally difficult to remove by laundering (35)(36)(37)(38)(39). Retention of triglycerides becomes more severe with successive soilings and washing.…”