Martin Camenzind

Thermal energy transfer through heat protective clothing during a flame engulfment test

The flame engulfment test according to ISO 13506 assesses the protective performance of ready-made heat and flame protective clothing when exposed to a flash fire condition using an instrumented manikin. It uses a thermal model of the human skin to predict the risk of skin burns. This evaluation method is based on a pass/fail criterion, as either a burn is predicted or not. Therefore, it provides only limited information about the transfer of heat through the protective clothing. In this study, we investigated the use of the total transferred energy as an improved characterization method of the performance of the garments. We defined an energy transmission factor as the quotient between the transferred energy on the clothed manikin divided by the transferred energy registered by the nude manikin during calibration. We analyzed the performance of seven garments and show that the energy transmission factors can be assessed with very high repeatability. When comparing the results of the right and left arms and legs, we found very high correlation coefficients of 0.96 and 0.98, respectively, showing that the thermal insulation of the garments tested was very symmetrical. This new assessment method will be proposed for the revision of ISO 13506.

A new method to assess the influence of textiles properties on human thermophysiology. Part I

Purpose – The purpose of this paper is to determine the validity and inter-/intra-laboratory repeatability of the first part of a novel, three-phase experimental procedure using a sweating Torso device. Design/methodology/approach – Results from a method comparison study (comparison with the industry-standard sweating guarded hotplate method) and an inter-laboratory comparison study are presented. Findings – A high correlation was observed for thermal resistance in the method comparison study (r=0.97, p<0.01) as well as in the inter-laboratory comparison study (r=0.99, p<0.01). Research limitations/implications – The authors conclude that the first phase of the standardised procedure for the sweating Torso provides reliable data for the determination of the dry thermal resistance of single and multi-layer textiles, and is therefore suitable as standard method to be used by different laboratories with this type of device. Further work is required to validate the applicability of the method for textiles wit...

Flexible textile light diffuser for photodynamic therapy

In this article a new medical application is introduced using textile production techniques to deliver a defined radiation dose. The advantage for photodynamic therapy (PDT) is that a flat luminous textile structure can homogeneously illuminate unequal body surfaces. The optical properties of this two-dimensional luminous pad are characterized with a set of bench-scale tests. In vitro investigations on petri dishes with cultivated cells and first clinical tests on animal patients are promising. In addition first measurement results are presented together with an outlook to future developments.

Exercise intensity dependent relevance of protective textile properties for human thermo-physiology

During firefighting, thermoregulation is challenged due to a combination of harsh environmental conditions, high metabolic rates and personal protective clothing (PPC). Consequently, investigations of thermoregulation in firefighters should not only consider climate and exercise intensity, but technical properties of textiles too. Therefore, laboratory textile performance simulations may provide additional insights into textile-dependent thermoregulatory responses to exercise. In order to investigate the thermo-physiological relevance of textile properties and to test how different garments affect thermoregulation at different exercise intensities, we analyzed the results of a standard laboratory test and human subject trials by relating functional properties of textiles to thermo-physiological responses. Ten professional, healthy, male firefighters (age: 43 ± 6 y, weight: 84.3 ± 10.3kg, height: 1.79 ± 0.05m) performed low and moderate intensity exercise wearing garments previously evaluated with a sweating torso system to characterize thermal and evaporative properties. Functional properties of PPC and the control garment differed markedly. Consequently, skin temperature was higher using PPC at both exercise intensities (low: 36.27 ± 0.32 versus 36.75 ± 0.15℃, P < 0.05; moderate: 36.53 ± 0.34 versus 37.18 ± 0.23℃, P < 0.001), while core body temperature was only higher for PPC at moderate (37.54 ± 0.24 versus 37.83 ± 0.27℃, P < 0.05), but not low-intensity exercise (37.26 ± 0.21 versus 37.21 ± 0.19, P = 0.685). Differences in thermal and evaporative properties between textiles are reflected in thermo-physiological responses during human subject trials. However, an appropriate exercise intensity has to be chosen in order to challenge textile performance during exercise tests.

Evaluation of thermo-physiological comfort of clothing using manikins

This book chapter discusses the evaluation of thermo-physiological comfort of regular- (e.g., formal clothing, informal clothing, casual clothing) and specialized-clothing (e.g., first-responders’ protective clothing, defense-personnel’s protective clothing, healthcare-personnel’s protective clothing). For this the importance for measuring and evaluating the thermo-physiological comfort of clothing is comprehensively explained. In general the thermo-physiological comfort of clothing is widely measured using a sweating thermal manikin; thus working principles of different sweating thermal manikins (e.g., Finnish manikin “Coppelius,” Swiss manikin “SAM,” Hong Kong manikin “Walter,” United States manikin “Newton”) are outlined. Additionally the existing standard methods to evaluate and calculate the thermo-physiological comfort of clothing by manikins are elucidated. By using these methods, many researchers have further investigated the thermo-physiological comfort of different types of regular- and specialized-clothing in the last few decades. In this chapter the findings of these researchers are critically assessed. Through this critical assessment, different approaches to improve the thermo-physiological comfort of clothing are suggested. Finally the key issues related to the evaluation of thermo-physiological comfort of clothing are highlighted to provide the future research directions. These issues are mainly directed toward the development of state-of-the-art testing methods to measure the thermo-physiological comfort of clothing. Overall, this chapter will provide insight into designing clothing that can provide optimal thermo-physiological comfort to wearers in their daily life.

Testing of Hot-water and Steam Protective Performance Properties of Fabrics

This chapter discusses the testing and characterization of hot water and steam protective performance of clothing that is regularly worn by high-risk sector workers, namely firefighters, defense personnel, oil and gas industry workers, and cooks/chefs. In the introductory section of this chapter, the hazardous working environments faced by these workers are briefly highlighted in order to better understand the importance of testing and characterizing the hot water and steam protective performance of their clothing. Thereafter, various standardized or customized bench-scale tests aimed at evaluating the hot water and steam protective performance of the fabrics used in the clothing are introduced. The evaluation of the hot water and steam protective performance of whole garments using full-scale instrumented manikin tests is also described. In the last few years, with these bench-scale and full-scale tests, researchers have studied the hot water and steam protective performance of different types of fabrics and garments. In this chapter, these studies are briefly reviewed for characterizing the different factors that affect the hot water and steam protective performance of the fabrics or clothing. In general, it has been identified that these factors are mainly related to the fabric properties (e.g., thickness and air permeability), garment design (e.g., fit and style), and characteristics of the hot water or steam exposure (e.g., temperature, pressure). Finally, this chapter is concluded by highlighting some key issues related to the hot water and steam protective performance of the clothing. These issues are mainly related to the existing test methods and/or fabric materials used in the clothing. In the future, these issues need to be resolved in order to develop high performance hot water and steam protective clothing. This development could provide the better occupational health and safety for firefighters, defense personnel, industrial workers, and/or cooks/chefs.

Evaluation of heat and flame protective performance of clothing using manikins

In this chapter we discuss the evaluation of heat and flame protective performance of clothing regularly worn by the working personnel (e.g., firefighters, industry workers, soldiers), especially for work in hazardous fire and high-temperature environments. As the protective performance of clothing is mainly evaluated using flash fire manikins, this chapter firstly outlines the background of developing the manikins. To date, few instrumented stationary and dynamic flash fire manikins have been developed in different parts of the world. The design and working principle of these instrumented stationary and dynamic flash fire manikins are thoroughly discussed and compared. By employing the instrumented stationary flash fire manikins, different standardized methods have been developed in the last few decades for calculating the protective performance of clothing. Furthermore, many researchers used these standardized and/or customized methods to examine the protective performance of different types of clothing. This chapter analytically reviews the standardized methods and critically assesses the previously conducted research in order to develop an in-depth understanding of the protective performance of clothing. Finally, different key issues related to the protective performance evaluation of clothing are highlighted. In future, these issues need to be resolved in order to develop high-performance heat and flame protective clothing. These developments could provide a better protection and safety for the working personnel, namely firefighters, industry workers.