Harriet H. Prato

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

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.

In Vivo Cutaneous Response to Fabric Part V: Effect of Fiber Type and Fabric Moisture Content on Stratum Corneum Hydration1:

Fabric placed over human skin may change the stratum corneum (SC) hydration level, an important phenomenon because increases in normal levels of SC hydration pose potential health problems. The skin becomes more susceptible to abrasive damage, increases in permeability, and is more prone to microbial growth. The purpose of this study was to determine the effect of fiber type and fabric moisture content on SC hydration. Using three similarly constructed knit fabrics, six fabric type/moisture content combinations were selected for the tests. Using an occluded plastic dome, fabric samples were placed on both “normal” and “hydrated” volar forearm skin of subjects for a specified time period, then removed. Two minutes after removal, evaporative water loss and skin temperature were measured. The design of the study was a randomized complete block with all possible treatment combinations applied to each subject. Data were analyzed using analyses of variance on the linear and quadratic coefficients of best fit lines and Bonferroni t tests. For “normal” skin, SC hydration generally increased as fabric moisture content increased. The SC was significantly drier after being in contact with cotton fabric at regain than at the two moisture content levels above regain, and also under polyester fabric. For hydrated skin, the hydration state was significantly lower under the cotton fabric at regain than at 38.6% moisture content and at saturation, but was not significantly different under the polyester fabric at regain and at saturation.

Relationship of Fiber Content and Fabric Properties to Comfort of Socks

The purpose of the study was to investigate the relationship of fiber content and fabric properties to the subjective evaluation of comfort of socks and to determine the subjective evaluations and laboratory measurements that best predict comfort. Socks made from all synthetic or predominantly cotton fibers were worn during exercise. Laboratory measurements were made on samples of sock fabrics which had been washed but not worn. Subjective evaluations obtained from the participants during the wear study indicated that the socks made from synthetic fibers were slightly more comfortable than the predominantly cotton socks. Prior to the wear study the majority of participants had indicated that they would select cotton socks for maximum comfort. The subjective evaluations of sock softness and foot dryness were found to be the significant determinants of comfort. Neither fiber content nor any of the laboratory measurements (weight, thickness, moisture absorption, air permeability, compressibility, and compressional resiliency) were found to be good predictors of comfort.

Comfort Of Warm-Up Suits During Exercise As Related To Moisture Transport Properties Of Fabrics

To assess the relationship between comfort and moisture transport properties of warm-up suit fabrics, a wear study was designed in which physiological and subjective measurements were obtained from subjects wearing warm-up suits under controlled conditions of exercise and environment. During the wear study, the subjects were under moderate heat stress in the warm environment and under no heat stress in the cool environment. Three fabrics were used in the study. Two of the fabrics were similar in thickness and insulative value but differed in ability to absorb and transport moisture. The other fabric had moisture properties that were similar to one of the above fabrics, but it was thinner and had a lower insulative value. Under cool environmental conditions the three fabrics provided similar levels of comfort. When the wearers were subjected to moderate heat stress, they were most comfortable when wearing either the thinnest fabric or the fabric which absorbed and transported the most moisture. Comparisons between the two fabrics with similar insulative values indicated that the under garments contained less moisture and the wearers felt drier when wearing the suit which had better moisture transport properties. Laboratory measurements of liquid transport and drop absorption were the best predictors of subjective eval uations of wetness and differences in the amounts of moisture in the garments when worn under conditions of moderate heat stress.

IN VIVO CUTANEOUS AND PERCEIVED COMFORT RESPONSE TO FABRIC. PART VI : THE EFFECT OF MOIST FABRICS ON STRATUM CORNEUM HYDRATION

Materials placed over human skin may change the stratum corneum (sc) hydration level, an important phenomenon because increases in normal levels of sc hydration pose potential health problems. This study examines the relationship between fabric moisture content and level of sc hydration so that the role of fabric moisture on sc hydration may be better understood. Three fabric/moisture treatments are placed on the sc—3.5-denier polyester fabric with an initial moisture content of 35% and cotton fabrics with either 44% or 75% initial moisture content—then covered with an occlusive dome. sc evaporative water loss (ewl) is measured before treatment placement and after 30 and 60 minutes of contact. The amount of moisture in the fabric at time of removal is calculated two different ways, and three analyses of variance are done using the evaporative water loss and two fabric final moisture content data sets. The rate of ewl is significantly higher after 30 minutes of treatment contact with sc than after 60 minutes of contact. The amount of moisture in the fabrics is significantly less at time 60 than at time 30, implying that the sc is more hydrated at 30 minutes than at 60 minutes. However, the fabrics contain less moisture when removed at 60 minutes than at 30 minutes. As fabric moisture content decreases, sc hydration decreases. The question we are not able to answer is “Where does the moisture go that is initially in the fabric?’

Effect of fiber type and fabric moisture content on the hydration state of human stratum corneum

Abstract 1. 1. The purpose of this study was to determine the effect of fiber type and fabric moisture content on SC hydration. 2. 2. Using three similarly constructed fabrics, six fabric type/moisture content combinations were selected. 3. 3. Fabric swatches were placed on both “normal” and “hydrated” volar forearm skin of five subjects for a specified period, then removed. 4. 4. Two minutes after removal, evaporative water loss (EWL) and skin temperature were measured. 5. 5. Data were analyzed using analyses of variance and Bonferroni t-tests. 6. 6. For normal skin, SC hydration generally increased as fabric moisture content increased. SC was significantly drier after being in contact with cotton swatches at regain than at the two moisture content levels above regain, and also under polyester swatches. 7. 7. For hydrated skin, hydration state was significantly lower under the cotton swatch at regain than at 38.6% moisture content or at saturation, but was not significantly different under the polyester swatch at regain or at saturation.

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

Response surface methodology was used to visualize the interactive effects of de tergent concentration, agitation time, and wash temperature on removal of soil from fabrics. Plots of the whiteness index of fabrics after repeated soiling and laundering indicated that maximum whiteness occurred at approximately 0.20% detergent con centration. The wash temperature required for maximum whiteness varied with fabric type. Changes in length of agitation time within the limits of the study had a minor effect on soil removal. Labeled components of synthetic sebum could be completely removed from acrylic and nylon fabrics. Both polar and nonpolar components became trapped in the cotton fibers. Removal of nonpolar triolein from polyester was in complete and decreased as wash temperature increased. Particulate soil, as measured by x-ray fluorescence of silicon, could be completely removed from all fabrics except the acrylic.

Line-Dried vs. Machine-Dried Fabrics: Comparison of Appearance, Hand, and Consumer Acceptance

The objectives of this study were to evaluate the effect of line drying on smooth ness and stiffness of fabrics, to determine whether consumer acceptance of fabric appearance and hand is related to certain economic and attitudinal factors, and to evaluate changes in the laundering process that would optimize the appear ance and hand of line-dried fabrics. Smoothness and stiffness of fabrics were measured after machine, line, and modified line-drying treatments. Consumer participants rated the acceptability of fabric appearance and hand, and responded to questions about their attitudes toward energy conservation and environmental concern. In most cases, line-dried fabrics were significantly stiffer than machine- dried fabrics but were equally acceptable with respect to hand. Line drying re sulted in a more wrinkled appearance which was less acceptable than the ap pearance of machine-dried fabrics. Factors which were related to the acceptance of fabric appearance were knowledge of the cost of machine drying, the fastid iousness of the individual, and attitude toward conservation. Briefly tumbling previously line-dried fabrics in a machine dryer resulted in appearance and hand that would have been acceptable to most consumer participants while still saving energy.

Performance of Garments Related to Initial Cost and Care

A wear study, which included 30 different mens shirts varying in color and price, was con ducted to determine the long-term effects of washing temperature and the price/quality relationships with respect to garment performance. After 40 wash/wear cycles, there were few differences in color change, appearance, and soil removal resulting from laundering in hot water as compared to warm water. Little color transfer was found during the washing process. The wear study results and laboratory measurements of color change, wrinkle recovery, seam strength, and fabric strength were related to shirt price. The lower-priced shirts were found generally to have better overall perfor mance than the higher-priced garments.

The Influence of Individual Differences on Garment Wear and Wear Evaluation

Using correlation and stepwise multiple regression techniques, the garment wear scores from a wear study of mens polyester/cotton durable-press trousers were found to be related to: (1) an estimate of the physical activity of the wearer during the wear period, (2) the wearers height and weight, and (3) Thurstone temperament scores for Dominant and Vigorous. For this sample of 22 men, the resulting regression equation accounted for 67% of the wear score variability. The correlation between the wearers estimate of the severity of wear and the garment wear score was low. The addition of Thurstone temperament scores for Active, Impulsive, Dominant and Reflective improved the prediction of the regression equation and indicated the importance of personality characteristics in the evaluation of wear.