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One week sweating simulation test with a thermal foot model

Kuklane, Kalev LU ; Holmér, Ingvar LU and Giesbrecht, Gordon (2000) The third international meeting on thermal manikin testing (3IMM) In Arbete och hälsa p.106-113
Abstract
This study aimed to find out how the insulation of the footwear changes over one week of use. A thermal foot model with 8 measuring zones and 5 “sweat glands” was used for tests. A thin sock was donned on the model to allow better water distribution all over the foot surface. Four boots were tested over a period of 5 days. Each day was divided into 9 hour measurement period and 15 hour conditioning period. Boots WS and WN were measured at -10.7±0.9 °C and conditioned at room temperature (20.1±0.5 °C, RH 39±6 %). SG was measured at -20.8±1.0 °C and conditioned in a refrigerator at -5.0±0.8 °C (RH 35±6 %). Due to problems with refrigerator SM was conditioned in an insulated box in cold chamber. However, due to the cold chamber working regime... (More)
This study aimed to find out how the insulation of the footwear changes over one week of use. A thermal foot model with 8 measuring zones and 5 “sweat glands” was used for tests. A thin sock was donned on the model to allow better water distribution all over the foot surface. Four boots were tested over a period of 5 days. Each day was divided into 9 hour measurement period and 15 hour conditioning period. Boots WS and WN were measured at -10.7±0.9 °C and conditioned at room temperature (20.1±0.5 °C, RH 39±6 %). SG was measured at -20.8±1.0 °C and conditioned in a refrigerator at -5.0±0.8 °C (RH 35±6 %). Due to problems with refrigerator SM was conditioned in an insulated box in cold chamber. However, due to the cold chamber working regime it warmed up during night and the average conditioning temperature was 0.9±4.1 °C (RH 78±6 %). SM was measured at -18.7±0.8 °C. The inner-boots and insoles of SG and SM were taken out over night. The first measuring hour was without sweat simulation. During the following 8 hours the water was distributed at a rate of 5 g/h with a peristaltic pump. Footwear was weighed in the beginning and end of each measurement day. Up-down motion at 8 steps (with same foot) per minute was simulated with the help of pneumatic system. Wind from front of 1.5±0.5 m/s (measured at ankle level) was applied. The surface temperature of the foot was kept at 30 °C. The sock dried to start weight over night at room temperature and in the refrigerator (boots WS, WN and SG). In boot SM the water from sock did not evaporate totally over night. Starting from the second day there was observed little frost between shell and inner-boot of SG and between outer and middle layer of SM. The amount of frost increased with each following day. The footwear insulation reduced considerably over 5 days period. The biggest reduction occurred during the first hours of the first day, and could be related to the onset of sweating. Similar, but somewhat smaller change was observed in the beginning of each day. The boots WS and WN did not dry at room temperature over night. During the tests there was minimal evaporation from the footwear due to low environmental temperature. The main heat losses could be related to the increased heat conductivity of the wet footwear insulation. It can be concluded that the footwear insulation reduces considerably over a week if no measures are taken to dry the footwear between use. The possibility to take out the insulation layers enhances the drying. The use of footwear dryers or warm air blowers to dry the footwear between work passes, the often change of socks and the use of absorbing materials inside the footwear at once after doffing them can be recommended. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Arbete och hälsa
editor
Nilsson, Håkan; Holmér, Ingvar; and
issue
2000:4
pages
8 pages
publisher
National Institute for Working Life
conference name
The third international meeting on thermal manikin testing (3IMM)
ISSN
0346-7821
ISBN
91-7045-554-6
language
English
LU publication?
no
id
5d61385d-c0a3-4b94-92b7-3e0068d8bd94 (old id 634838)
alternative location
http://hdl.handle.net/2077/4250
date added to LUP
2008-05-20 15:25:23
date last changed
2016-04-16 03:43:53
@inproceedings{5d61385d-c0a3-4b94-92b7-3e0068d8bd94,
  abstract     = {This study aimed to find out how the insulation of the footwear changes over one week of use. A thermal foot model with 8 measuring zones and 5 “sweat glands” was used for tests. A thin sock was donned on the model to allow better water distribution all over the foot surface. Four boots were tested over a period of 5 days. Each day was divided into 9 hour measurement period and 15 hour conditioning period. Boots WS and WN were measured at -10.7±0.9 °C and conditioned at room temperature (20.1±0.5 °C, RH 39±6 %). SG was measured at -20.8±1.0 °C and conditioned in a refrigerator at -5.0±0.8 °C (RH 35±6 %). Due to problems with refrigerator SM was conditioned in an insulated box in cold chamber. However, due to the cold chamber working regime it warmed up during night and the average conditioning temperature was 0.9±4.1 °C (RH 78±6 %). SM was measured at -18.7±0.8 °C. The inner-boots and insoles of SG and SM were taken out over night. The first measuring hour was without sweat simulation. During the following 8 hours the water was distributed at a rate of 5 g/h with a peristaltic pump. Footwear was weighed in the beginning and end of each measurement day. Up-down motion at 8 steps (with same foot) per minute was simulated with the help of pneumatic system. Wind from front of 1.5±0.5 m/s (measured at ankle level) was applied. The surface temperature of the foot was kept at 30 °C. The sock dried to start weight over night at room temperature and in the refrigerator (boots WS, WN and SG). In boot SM the water from sock did not evaporate totally over night. Starting from the second day there was observed little frost between shell and inner-boot of SG and between outer and middle layer of SM. The amount of frost increased with each following day. The footwear insulation reduced considerably over 5 days period. The biggest reduction occurred during the first hours of the first day, and could be related to the onset of sweating. Similar, but somewhat smaller change was observed in the beginning of each day. The boots WS and WN did not dry at room temperature over night. During the tests there was minimal evaporation from the footwear due to low environmental temperature. The main heat losses could be related to the increased heat conductivity of the wet footwear insulation. It can be concluded that the footwear insulation reduces considerably over a week if no measures are taken to dry the footwear between use. The possibility to take out the insulation layers enhances the drying. The use of footwear dryers or warm air blowers to dry the footwear between work passes, the often change of socks and the use of absorbing materials inside the footwear at once after doffing them can be recommended.},
  author       = {Kuklane, Kalev and Holmér, Ingvar and Giesbrecht, Gordon},
  booktitle    = {Arbete och hälsa},
  editor       = {Nilsson, Håkan and Holmér, Ingvar},
  isbn         = {91-7045-554-6},
  issn         = {0346-7821},
  language     = {eng},
  number       = {2000:4},
  pages        = {106--113},
  publisher    = {National Institute for Working Life},
  title        = {One week sweating simulation test with a thermal foot model},
  year         = {2000},
}