10
E. Classen
trials. The fabrics show high values of the wicking power and the cooling power and
the average value over a certain time period. The three fabrics show good cooling
behavior.
The test persons rate the perception (temperature, humidity and comfort) on a
rating box during the subject trials. The subjective temperature is rated by a modified
seven-point Bedfort scale [3]: 1 too cold, 2 cold, 3 slightly cold, 4 neutral, 5 warm,
6 hot and 7 too hot. For humidity, a four-level scale is used: 1 dry, 2 slightly moist, 3
moist and 4 wet. The details of this analysis are reported in the project report [4]. The
analysis of all data which are received from the wearer trials show that fabric 2 tends to
be the best during and in the end the activity program in the temperature and humidity
perception. These results were confirmed by the results of the questionnaires after
every subject trial and the results of the objective data. Fabric 2 shows also the best
values in the investigation with WATson.
4 Conclusion
Differences between cooling textiles could be shown by means of heat release tester
WATson and wear trials. WATson test design can show differences in the heating
power of different cooling textiles during the test program. The test program simulates
the human sweating during activities in warm conditions (temperature 25 °C, relative
humidity 50 %) and the time after activities. The first 10 min simulates the nonsweating phase (pre-exercise state) representative for low metabolic rates without
sweating. After 10 min, the sweating is starting for 1 h. This represents high metabolic
rates with liquid sweat occurring and equates the evaporative heat loss of the human
skin covered with the wet test specimen. After 70 min, the sweating is stopped, and
this represents the activity by rest with low metabolic rates. This equates the wet heat
loss of the human skin covered with the test specimen in wet to dry transition and the
drying time of the test specimen on the human skin. The evaporative cooling power
of a tested sample in the sweating phase can be displayed as a total average over the
sweating phase and as a steady-state average over the last 10 min of the sweating
phase. The closer these 2 bars are together the quicker the build-up of the maximum
evaporative cooling power is. The further these 2 bars are apart the longer it takes
to build up the maximum evaporative cooling power. The drying performance after
activity can be displayed as a momentary value at the 75th min of the test and the
average over the first 10 min of drying out of the sample. The lower the value at the
75th minute and the higher the average value between 70 and 80th minute the quicker
the fabric dries. The higher the value at the 75th minute and the lower the average
value between 70 and 80th minute the longer the fabric dries. The wearer trials of
three different garments show that the results of objective and subjective parameters
of the tested garments are similar and fabric 2 is judged as the best one which is seen
in the WATson test. Because the three tested fabrics have similar properties further
wearer trials with cooling textiles will be performed in the future to correlate the data
of wearer trials.
E. Classen
trials. The fabrics show high values of the wicking power and the cooling power and
the average value over a certain time period. The three fabrics show good cooling
behavior.
The test persons rate the perception (temperature, humidity and comfort) on a
rating box during the subject trials. The subjective temperature is rated by a modified
seven-point Bedfort scale [3]: 1 too cold, 2 cold, 3 slightly cold, 4 neutral, 5 warm,
6 hot and 7 too hot. For humidity, a four-level scale is used: 1 dry, 2 slightly moist, 3
moist and 4 wet. The details of this analysis are reported in the project report [4]. The
analysis of all data which are received from the wearer trials show that fabric 2 tends to
be the best during and in the end the activity program in the temperature and humidity
perception. These results were confirmed by the results of the questionnaires after
every subject trial and the results of the objective data. Fabric 2 shows also the best
values in the investigation with WATson.
4 Conclusion
Differences between cooling textiles could be shown by means of heat release tester
WATson and wear trials. WATson test design can show differences in the heating
power of different cooling textiles during the test program. The test program simulates
the human sweating during activities in warm conditions (temperature 25 °C, relative
humidity 50 %) and the time after activities. The first 10 min simulates the nonsweating phase (pre-exercise state) representative for low metabolic rates without
sweating. After 10 min, the sweating is starting for 1 h. This represents high metabolic
rates with liquid sweat occurring and equates the evaporative heat loss of the human
skin covered with the wet test specimen. After 70 min, the sweating is stopped, and
this represents the activity by rest with low metabolic rates. This equates the wet heat
loss of the human skin covered with the test specimen in wet to dry transition and the
drying time of the test specimen on the human skin. The evaporative cooling power
of a tested sample in the sweating phase can be displayed as a total average over the
sweating phase and as a steady-state average over the last 10 min of the sweating
phase. The closer these 2 bars are together the quicker the build-up of the maximum
evaporative cooling power is. The further these 2 bars are apart the longer it takes
to build up the maximum evaporative cooling power. The drying performance after
activity can be displayed as a momentary value at the 75th min of the test and the
average over the first 10 min of drying out of the sample. The lower the value at the
75th minute and the higher the average value between 70 and 80th minute the quicker
the fabric dries. The higher the value at the 75th minute and the lower the average
value between 70 and 80th minute the longer the fabric dries. The wearer trials of
three different garments show that the results of objective and subjective parameters
of the tested garments are similar and fabric 2 is judged as the best one which is seen
in the WATson test. Because the three tested fabrics have similar properties further
wearer trials with cooling textiles will be performed in the future to correlate the data
of wearer trials.