Apparatus for Evaluating Warmth of Textile Fabrics

Abstract

A semi-automatic apparatus requiring minimum operator attention has been assembled for measuring the thermal transmission of fabrics while subject to moving air at constant tem perature. The apparatus employs the principle of measuring the difference in the amount of energy required to maintain constant temperature in a body when bare and when covered with the test specimen. Conditions have been set up with an air velocity of 12 to 13 m.p.h. so that per formance under fairly severe conditions of use can be approximated. Results are expressed as "thermal efficiency." Formulas are given for converting to other units as desired. The ap paratus has been tested with a variety of fabrics ranging from thin, plain-weave, nylon cloth to heavy woolen blankets, and has been found to differentiate among them in a manner that ap parently takes into account the various fabric properties.