Advanced

Insulation of safety footwear: effects of steel toe cap in the cold

Kuklane, Kalev LU (1997)
Abstract (Swedish)
Abstract in Uncoded languages

Praegune kaitsejalatsite testimise standard (EN 344) kontrollib soojapidavuslikke omadusi vaid jalatsi ühes punktis mõõtes temperatuuri muutust. Meetod, mis kasutab termilist jala mudelit võimaldab mõõta jalatsi soojaisolatsiooni üheaegselt erinevates piirkondades ning ühtlasi ka jalatsi kui terviku soojaisolatsiooni.

Selle uurimuse käigus on soojendatava jala meetodit edasi arendatud. Praegu on võimalik simuleerida higistamist ja hinnata niiskumisest ja aurustumis-soojakadudest põhjustatud soojapidavuse vähenemist.

Käesolevas töös hinnati erinevate soojapidavusastmega kaitsejalatseid (alates õhukestest kummisaabastest kuni paksude talvesaabasteni). Jalatsid toodeti nii... (More)
Abstract in Uncoded languages

Praegune kaitsejalatsite testimise standard (EN 344) kontrollib soojapidavuslikke omadusi vaid jalatsi ühes punktis mõõtes temperatuuri muutust. Meetod, mis kasutab termilist jala mudelit võimaldab mõõta jalatsi soojaisolatsiooni üheaegselt erinevates piirkondades ning ühtlasi ka jalatsi kui terviku soojaisolatsiooni.

Selle uurimuse käigus on soojendatava jala meetodit edasi arendatud. Praegu on võimalik simuleerida higistamist ja hinnata niiskumisest ja aurustumis-soojakadudest põhjustatud soojapidavuse vähenemist.

Käesolevas töös hinnati erinevate soojapidavusastmega kaitsejalatseid (alates õhukestest kummisaabastest kuni paksude talvesaabasteni). Jalatsid toodeti nii terasvarbakaitsega kui ka ilma selleta ja see võimaldas uurida terasninamiku termilist mõju erinevates tingimustes.

Lisaks mõõtmistele jala mudeliga tehti mõõtmisi ka katseisikutega. Tulemusi kombineeriti kaitsejalatsite soojapidavuslike omaduste hindamiseks.

Kaitsejalatsite soojaisolatsioon võib kõikuda sõltuvalt jalatsi piirkonnast ja saapa soojaisolatsiooni astmest. Soojade talvesaabaste kõige nõrgemini soojustatud piirkond oli varbad ja ilma sooja hoidva kihita saabastel oli selleks piirkonnaks kand. Higistamise simuleerimine (10 g/h 1.5 tunni jooksul) vähendas jalatsite soojaisolatsiooni 30-37 % sõltuvalt jalatsi soojaisolatsiooni astmest. Kahanemine oli suurem talvesaabaste puhul. Näib, et terasvarbakaitse mõjutab jala nahatemperatuuri ja muudab soojakadusid jalast.



Popular Abstract in Swedish

Nuvarande standard om skyddsskor (EN 344) testar den termiska isoleringen bara i en punkt i skor genom att mäta en temperaturändring. Metoden som använder en termisk fotmodell möjliggör att mäta isolation hos skor båda i olika zoner och i hela skon.

I detta forskningsprojektet har metoden med uppvärmd fot modell vidare-utvecklas. Det är möjligt att simulera svettning och bestämma ändring i isolation av skor beroende på fukt och värmeförlust genom avdunstning.

I projektet har skyddsskor med olika isoleringsnivåer (från tunna gummistövlar till tjocka vinterstövlar) undersökts. Skorna var tillverkade båda med och utan stålhätta och den termiska påverkan av stålhättan under olika betingelser studerades.

Förutom mätningar på fotmodell gjordes försök med försökspersoner. För att bedöma termiska egenskaper hos skyddsskorna användes data från försökspersoner och fotmodell tillsammans.

Isolationen hos skyddsskor varierar beroende på område, tjocklek och materjal. Varma vinterstövlar hade den lägsta isolationen vid tårna medan den kallaste zonen i gummistövlar var vid hälen. Simulering av svettning (10 g/h) minskade isolationen med 30-37 % beroende på modell. Minskningen var större i vinterstövlar. Det förefaller som om stålhättan har en inflytande om än litet på fotens hudtemperatur och modifierar värmeförlusterna från foten. (Less)
Abstract
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... (More)
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. (Less)
Please use this url to cite or link to this publication:
author
supervisor
organization
publishing date
type
Thesis
publication status
published
subject
pages
23 pages
publisher
Luleå University of Technology
language
English
LU publication?
no
id
8e9809cb-f7a6-43b3-998b-9b06ac5b93cd (old id 591847)
alternative location
http://pure.ltu.se/portal/files/106197353/LTU_LIC_9727_SE.pdf
date added to LUP
2008-09-24 13:13:51
date last changed
2016-10-26 09:28:01
@misc{8e9809cb-f7a6-43b3-998b-9b06ac5b93cd,
  abstract     = {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.<br/><br>
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.<br/><br>
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.<br/><br>
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.<br/><br>
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.},
  author       = {Kuklane, Kalev},
  language     = {eng},
  note         = {Licentiate Thesis},
  pages        = {23},
  publisher    = {Luleå University of Technology},
  title        = {Insulation of safety footwear: effects of steel toe cap in the cold},
  year         = {1997},
}