Fabric Material Properties

Aaron Packard

Me En 340 Heat Transfer

16 April 2007

Introduction

• Body uses evaporative cooling for temperature regulation

• Jersey material influences the effectiveness of evaporative cooling

• Influential factors

– Material conduction coefficient

– Fabric weave and pattern

– Moisture wicking capabilities

• Compared Cotton to Polyester

Heat Transfer Problem

• Calculated convective heat coefficient for free convection

• Thermal conductivity of fabric varies with:

– Material

– Weave and fabric pattern

– Moisture content

• Heat generation of body is dependent on current metabolic rate

Solution

• Difficulty of modeling

• Experimentation

– Measure body surface temperature

– Warm up with heart rate at 153 bpm

– Stop at steady state surface temperature

– Cool down with fan

Results and Conclusions

• Shirt – Less wicking of moisture causes

perspiration to remain closer to the skin and reduces the amount of heat that can be transferred from the surface through evaporative cooling.

• Jersey– Better breath-ability– Wicks moisture and diffuses it

over a greater surface area allowing for more effective evaporative cooling.

Body Surface Temperature

82

84

86

88

90

92

94

96

98

0 100 200 300 400 500 600 700 800 900

Time (Sec)

Tem

pera

ture

(F)

Jersey

T-Shirt