4
E. Classen
effect of textile material is not limited to the use of clothing textiles; the cooling
effect is also interesting in the field of bedding, seats and technical textiles.
The cooling of a textile cannot be determined with the conventional test methods
of the clothing physiology. To determine the cooling power of fabrics, the new heat
release tester WATson was developed in Hohenstein. With WATson, the cooling
power of cooling materials can be determined and compared. However, the measured
cooling power is only a physical value. Without the correlation of these values with
data of subject trials, the cooling power does not give any information about the
perception of the human body and the achieved cooling effect.
2 Materials and Methods
2.1 Materials
The textile materials were commercially available fabrics for sport wear (see Table
1). The material composition was taken from the product information of the manufacturer. The mass per unit was determined according to DIN EN 12127. The thickness
was determined according to DIN EN ISO 53855.
All fabric samples were washed once prior to testing on household washing,
30 °C, line drying with a standard detergent (ECE-2 Standard Detergent 1998) in
accordance with ISO 6330 (procedure 4M for polyester (PES), polyamide (PA) and
polypropylene and procedure N for cotton (CO)).
For sample preparation, three specimens measuring 25 cm × 25 cm were cut
out. The test specimens were conditioned for 12 h prior to measurement under the
climatic conditions of the testing protocol.
2.2 WATson
The test device WATson is placed in a climate chamber to ensure constant and defined
ambient climate during the test run (ambient temperature (T a ) of 30 ± 0.5 °C and
relative humidity of in the climate chamber (rH a ) of 70% ± 10%). The evaporative
heat loss test device WATson consists of a heated plate with sweat glands and is
technically and electrically designed to mimic human thermoregulation (see Fig. 1).
The area of the measuring head is 400 cm
2 (20 cm × 20 cm). The heated plate
is set to an average skin temperature (T s ) of 32 ± 0.1 °C. The temperature of the
measuring head is held constant at the set temperature by controlled electrical heating.
This electrical heating power to maintain this set temperature (i.e., the heat loss) is
recorded at 1 datapoint per second (1 Hz) and is stated as “P heating ” in W.
The four inner sweat glands supply deionized water (i.e., “sweat”) via a peristaltic
pump with a pumping rate (i.e., sweat rate) of 8 ± 0.1 g/h. Wind is one important
E. Classen
effect of textile material is not limited to the use of clothing textiles; the cooling
effect is also interesting in the field of bedding, seats and technical textiles.
The cooling of a textile cannot be determined with the conventional test methods
of the clothing physiology. To determine the cooling power of fabrics, the new heat
release tester WATson was developed in Hohenstein. With WATson, the cooling
power of cooling materials can be determined and compared. However, the measured
cooling power is only a physical value. Without the correlation of these values with
data of subject trials, the cooling power does not give any information about the
perception of the human body and the achieved cooling effect.
2 Materials and Methods
2.1 Materials
The textile materials were commercially available fabrics for sport wear (see Table
1). The material composition was taken from the product information of the manufacturer. The mass per unit was determined according to DIN EN 12127. The thickness
was determined according to DIN EN ISO 53855.
All fabric samples were washed once prior to testing on household washing,
30 °C, line drying with a standard detergent (ECE-2 Standard Detergent 1998) in
accordance with ISO 6330 (procedure 4M for polyester (PES), polyamide (PA) and
polypropylene and procedure N for cotton (CO)).
For sample preparation, three specimens measuring 25 cm × 25 cm were cut
out. The test specimens were conditioned for 12 h prior to measurement under the
climatic conditions of the testing protocol.
2.2 WATson
The test device WATson is placed in a climate chamber to ensure constant and defined
ambient climate during the test run (ambient temperature (T a ) of 30 ± 0.5 °C and
relative humidity of in the climate chamber (rH a ) of 70% ± 10%). The evaporative
heat loss test device WATson consists of a heated plate with sweat glands and is
technically and electrically designed to mimic human thermoregulation (see Fig. 1).
The area of the measuring head is 400 cm
2 (20 cm × 20 cm). The heated plate
is set to an average skin temperature (T s ) of 32 ± 0.1 °C. The temperature of the
measuring head is held constant at the set temperature by controlled electrical heating.
This electrical heating power to maintain this set temperature (i.e., the heat loss) is
recorded at 1 datapoint per second (1 Hz) and is stated as “P heating ” in W.
The four inner sweat glands supply deionized water (i.e., “sweat”) via a peristaltic
pump with a pumping rate (i.e., sweat rate) of 8 ± 0.1 g/h. Wind is one important