The microclimate in protective footwear – study with use of a thermal foot model

W artykule przedstawiono wyniki badań mikroklimatu obuwia ochronnego wyznaczonego na termicznym modelu stopy. Stwierdzono, że w obuwiu ochronnym z podnoskami kompozytowymi stopa jest lepiej wentylowana z uwagi na paroprzepuszczalny charakter materiału w okolicy palców, w porównaniu do obuwia z podnoskami metalowymi. Izolacyjność obuwia była lepsza w przypadku występowania w obuwiu podnosków metalowych. Wartości odchylenia standardowego potwierdziły mały rozrzut wyników pomiarów; wartości względnego błędu przypadkowego wartości średniej (przy p=0,95) potwierdziły dobrą dokładność przyrządu pomiarowego.This paper presents investigation results of microclimate parameters of protective footwear for a thermal foot model. The standards harmonized with the Directive 89/686/EEC are currently used for assessing protective properties. They concern only assessment of hygienic materials used in manufacturing [1-6]. An alternative can be tests on a thermal foot model fit in terms of the feasibility of five variants of construction protective footwear (with high upper) [7-9]. The study was performed on the thermal foot model which ensures the release of water in a manner similar to human sweat glands and heat dissipation by conduction, convection and radiation in proportions similar to those at different speeds of real sweat, different time use of the footwear and different possibilities of simulated movement of the foot. The test method includes monitoring the simulated release of moisture in seven segments and heat release in nine independent isothermal zones (Figs. 3, 4). Based on the results, it was found that the footwear with a composite toe cap foot (Fig. 1) was better ventilated (Fig. 5) because of permeable material around the fingers, compared to the footwear with a steel toecap (Fig. 2). There was greater loss of insulation for the footwear with a composite toecap with and without a function of perspiration (Fig. 6). The values of standard deviations and variation coefficients confirmed the small scattering of measurements, the values of the relative random error of the mean (at p = 0.95) confirmed the good accuracy of the measuring instrument (Tables 5, 6)