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Xerox University Microfilms 300 North Zeeb Road Ann Arbor, Michigan 48106 I 76-6510 CRIPPEN, Loretta Kaye, 194$- MOISTURE TRANSPORT PROPERTIES OF SELECTED KNIT FABRICS. The University of North Carolina at Greensboro, Ph.D., 1975 Home Economics Xerox University Microfilms , Ann Arbor, Michigan 48106 @ 1975 LORETTA KAYE CRIPPEN ALL RIGHTS RESERVED MOISTURE TRANSPORT PROPERTIES OF SELECTED KNIT FABRICS by Loretta Kaye Crippen A Dissertation Submitted to the Faculty of the Graduate School at The University of North Carolina at Greensboro in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Greensboro 1975 Approved by Dissertation Adviser APPROVAL PAGE This dissertation has been approved by the following committee of the Faculty of the Graduate School at The University of North Carolina at Greensboro, Dissertation 'VVWgJ.L. 9l *4 v l R 15~ Date of Acceptance by" Committee ii CRIPPEN, LORETTA KAYE. Moisture Transport Properties of Selected Knit Fabrics. (1975). Directed by Dr. Victor Salvin. Pp. 291. The purpose of this research was to examine the role of fiber content and fabric structure on the moisture transport properties of selected knit fabrics. Moisture transport is an important factor in clothing comfort as related to evaporative cooling. Test fabrics included jersey and interlock weft knit structures in 100 percent cotton, 100 percent polyester, and 50/50 percent cotton/ polyester. The knits represented double and single knit structures and hydrophobic, hydrophilic, and blended fibers. No standard moisture transport test methods have been adopted for apparel fabrics. Most tests used previously measured only vapor transport in ambient air currents. A series of four moisture transport tests were developed to more fully replicate use conditions which included vapor and liquid transport with and without moderate air currents over the upper surface of the fabric. The volumetric test method developed used a water filled vessel attached to a capillary tube. The amount and rate of moisture transport were determined. The vapor tests were performed with the fabric 1.5 cm from the moisture surface. A wicking polyurethane sponge, in contact with the water supply and test fabric, was used for the liquid test method. Differences in data were due to variations in experimental procedure and variations in knit structure and finishing. The moisture transport test series examined two fabric variables, fiber content and fabric structure, and two treatment variables, air velocity and moisture form. Four-way analysis of variance suggested that the following main effects were statistically significant at the .05 level: fiber content, fabric structure, and air velocity. Newman-Keuls1 statistical analysis suggested that moisture transport rate for 50/50 percent cotton/polyester, the fastest transporter, did not significantly differ from 100 percent polyester. However, the 50/50 percent cotton/ polyester and the 100 percent polyester differed signifi­ cantly from 100 percent cotton, the slowest transporter. The interlock knit structures transported signifi­ cantly more moisture than the jersey knit structures. The use of moderate air currents over the upper surface of the fabric resulted in a significant increase in moisture transport over the use of ambient air. The following interaction effects were suggested to be significant at the .05 level: fabric structure/air velocity, fiber content/moisture form, fiber content/air velocity, fabric structure/fiber content/moisture form, fabric structure/fiber content/air velocity, and fiber content/moisture form/air velocity. No significant first- order interaction effect was suggested between fiber content and fabric structure. Spearman rho rank order correlation was used to determine whether a relationship existed between the following: (1) various tests in the moisture transport test series, (2) tests in the moisture transport test series and basic fabric property tests such as vertical wicking which are frequently used as indicators of moisture transport, and (3) various basic fabric properties. No correlations were statistically significant between the various tests in the moisture transport test series which used either the same moisture form or air velocity. Not all the tests in the moisture transport series suggested a correlation with a basic fabric property. Use of the four tests in the moisture transport test series was recommended to more fully replicate use conditions. Additional research to examine moisture transport as related to physiological clothing comfort; is needed. A standard test method which replicates various use condi­ tions should be adopted for industry use. ACKNOWLEDGEMENTS The author wishes to thank everyone who offered technical assistance and encouragement during this research project. Special appreciation is expressed to Dr. Victor Salvin who directed the dissertation. Other committee members who offered assistance included Dr. Eunice Deemer, Dr. Mildred Johnson, Dr. Pauline Keeney, Dr. Sigrid Trombley, and the late Dr. Frances Buchanan. Thanks is expressed to Dr. Richard Resurreccion who prepared the diagrams. Appreciation is expressed to everyone who aided with the statistical and computer analyses. Gratitude is expressed to the textile companies that donated test fabrics for this research. Additional thanks are expressed to the faculty at California State University at Los Angeles, family, and friends for their encouragement. iii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS iii LIST OF TABLES x LIST OF FIGURES xiv Chapter 1. INTRODUCTION 1 STATEMENT OF THE PROBLEM 5 DEFINITIONS OF TERMS 6 2. REVIEW OF LITERATURE 9 CLOTHING COMFORT 9 HISTORY OF MOISTURE TRANSPORT RESEARCH ... 12 MOISTURE TRANSPORT MECHANISMS AND PROCESSES 13 SYSTEM VARIABLES 24 Environmental Variables 24 Physiological Variables 26 Clothing Variables 33 TEST APPARATUS AND PROCEDURES 52 Moisture Transport Tests 54 Basic Fabric Properties Tests 62 3. EXPERIMENTAL RESEARCH DESIGN AND PROCEDURE . 66 RESEARCH DESIGN 66 Moisture Transport Tests 66 Correlation 71 Assumptions and Limitations 73 iv Chapter Page TEST PROCEDURES 74 Test Specimen Preparation 74 List of Tests Performed 76 Moisture Transport Test Method 78 Evaluation of Wettability 90 Vertical Wicking Test Procedure 93 Percent Moisture Regain after Static Absorption 97 Moisture Imbibition after Centrifugation . 99 Designation of Yarn Construction 101 Wale Count 102 Thickness 102 Weight 102 Air Permeability 102 Dimensional Stability and Scouring .... 104 Moisture Regain 105 4. PRESENTATION OF DATA AND RESULTS . 106 DESCRIPTIVE PROPERTIES OF TEST FABRICS ... 107 MOISTURE TRANSPORT TEST SERIES Ill Main Effects 113 Interaction Effects 128 Summary of Moisture Transport Test Series 131 CORRELATIONS 134 CORRELATION BETWEEN MOISTURE TRANSPORT TESTS IN THE SERIES 135 v Chapter Page Correlations Between Vapor Form/Ambient Air and Vapor Form/Moderate Air Currents 136 Correlations Between Liquid Form/Ambient Air and the Liquid Form/Moderate Air Currents 137 Correlations Between Vapor Form/Ambient Air and Liquid Form/Ambient Air .... 137 Correlations Between Vapor Form/Moderate Air Currents and Liquid Form/Moderate Air Currents Tests 138 Summary of Correlations Between Tests in the Moisture Transport Test Series . 139 Correlation Between Tests in Moisture Transport Series and Fabric Property Tests Used as Indicators 140 Correlation Between Tests in the Moisture Transport Test Series and Vertical Wicking 141 Correlation Between Tests in the Moisture Transport Test Series and Drop Absorption 142 Correlation Between Tests in the Moisture Transport Test Series