Insulation of safety footwear: effects of steel toe cap in the cold
Author
Summary, in English
Present standard on safety footwear (EN 344) checks the insulation only at one point in the shoes by means of measuring the temperature change. A method that uses thermal foot model allows to measure footwear insulation simultaneously at various locations and for whole footwear as total.
In the cause of the present research the method of heated foot model has been developed further. Now it is possible to simulate sweating and evaluate reduction of insulation of footwear due to wetting and evaporative heat loss.
Safety footwear with various insulation levels (from thin rubber boots to thick winter boots) was evaluated. The footwear was manufactured both with and without steel toe cap and this allowed to study the thermal effect of steel toe cap in different conditions.
The subjects were used in addition to physical measurements on foot model. Data from subjects and foot model was used in evaluation of thermal properties of safety shoes.
The insulation of safety footwear can vary depending on region and insulation level of the footwear. Heavy winter boots had lowest insulation in toe zone and thin boots had heel zone as the coldest region. Sweat simulation (10 g/h during 1.5 hours) reduced insulation of a footwear 30-37 % depending on insulation. Reduction was bigger in warm winter boots. A steel toe cap in a footwear seems to have an influence on foot skin temperature and it modifies the heat losses from the foot.
In the cause of the present research the method of heated foot model has been developed further. Now it is possible to simulate sweating and evaluate reduction of insulation of footwear due to wetting and evaporative heat loss.
Safety footwear with various insulation levels (from thin rubber boots to thick winter boots) was evaluated. The footwear was manufactured both with and without steel toe cap and this allowed to study the thermal effect of steel toe cap in different conditions.
The subjects were used in addition to physical measurements on foot model. Data from subjects and foot model was used in evaluation of thermal properties of safety shoes.
The insulation of safety footwear can vary depending on region and insulation level of the footwear. Heavy winter boots had lowest insulation in toe zone and thin boots had heel zone as the coldest region. Sweat simulation (10 g/h during 1.5 hours) reduced insulation of a footwear 30-37 % depending on insulation. Reduction was bigger in warm winter boots. A steel toe cap in a footwear seems to have an influence on foot skin temperature and it modifies the heat losses from the foot.
Publishing year
1997
Language
English
Links
Document type
Licentiate thesis
Publisher
Luleå University of Technology
Topic
- Production Engineering, Human Work Science and Ergonomics
Status
Published
Research group
- Thermal Environment Laboratory
Supervisor
- Ingvar Holmér
- John Abeysekera