Advanced Materials Research Vol. 796

Abstract: Thermal insulation and flame-retardant (TIFR) protective clothing, which has good thermal protective performance (TPP), could protect people from high-temperature or flame in casting industry, the petrochemical industry, fire industry and et al. That is, TIFR protective clothing must have certain function of slowing or restraining heat transmission, and insulating radiant heat and convection heat from high temperature heat source. The construction of TIFR protective clothing is being developed from single layer to multi-layer fabrics made by flame-retardant (FR) fibre. In this paper, based on TPP-206 tester, the TPP coefficient of single and multi-layer fabrics with flame-retardant were measured, and the TPP of TIFR protective clothing was analyzed. TPP coefficient of single fabrics included the FR viscose non-woven fabric do not meet the standard. That of all of multi-layer fabrics meet the standard requirement, and the FR viscose/wool blended fabric is not suitable for fire fighter. It is significant and the most observable effect to put the PTFE membrane between the outer layer and the insulating layer. It could improve the overall thermal protection performance.

Abstract: Firefighter's protective clothing provide protection for the firefighter's torso, neck, arms, and legs, but excluding the head, hands. The performance index for textile burning behaviour include afterflame time, afterglow time, damaged length, damaged area, dimensional stability to heat, ignition time and so on. The purpose of Standard is to provide minimum performance requirements for protective clothing for firefighters, whilst fighting fires. Within national standard GB 8965.1-2009 protective clothing, flame-retardant protection, part 1: flame-retardant protective clothing, the performance requirement are divided into three grade: A grade, B grade, C grade. The performance requirements C grade is the lower level, A grade, the higher level. The level of personal protection chosen should be based on the outcome of a risk assessment. Within national standard GB/T 17591-2006 flame retardant fabrics, assessment criteria are divided into two grade: B1 grade and B2 grade. The performance requirements B2 grade is the lower level, B1 grade, the higher level. Within standard GA 634-2006 protective clothing for proximity fire fighting and GB/T 5444-1997 textiles-burning behaviour-vertical method, the performance requirement are not classification. In different standard, the test parameters, such as the specimen dimension, specimen quantity and the flame height, are different. In order to establish suitable standard system, some effective standard should be revised. The standard system should cover the general clothing design, the minimum performance levels of the materials used, and the methods of test to be used to determine these performance levels. For adequate overall protection against the risks to which firefighters are likely to be exposed, additional personal protective equipment to protect the head, face, hands and feet should also be worn, along with appropriate respiratory protection where necessary.

Abstract: Synthetic textile such as polyester and poly-urethane has been used for underwear in terms of moisture release and function in underwear. However, the synthetic underwear has high risk for skin burns due to melting and shrinking by heat. Thermal protection and comfort in fire fighter protective clothing is always trading off, but fire fighters tend to use the synthetic underwear to feel comfort and function during firefighting operation without understanding of the risk for skin burns by the textile. Objective of this study is to investigate if the synthetic underwear plays a significant role in moisture and metabolic heat transfer within the fire fighter clothing by total heat loss measurement. Measurement of the total heat loss has been conducted by the ASTM F-1868 instrument (Kato-Tech, Co. Ltd., Japan). Three type of fire fighter clothing, one station wear, and five types of underwear have been used for the test. Test has been conducted for each clothing and combination of clothing. The results shows that range of total heat loss is 322.3 W/m² to 385.3 W/m², 857.9 W/m², 782.3 W/m² to 897.3 W/m² for three fire fighter clothing, one station wear and five underwear, respectively. However, when the fabrics of fire fighter clothing, station wear and underwear were piled up, the range of total heat loss decreased to 242.1 W/m² to 304.4 W/m². The data indicates that the fire fighter's multi-layer fabric controls the heat and moisture transfer within fire fighter clothing and no positive contribution by any types of underwear.

Abstract: During firefighting, within firefighter clothing, underwear and station wear gets heavily wet due to firefighting water and moisture from the body. Water has higher thermal conductivity relative to air and it has been expected that heavily wet condition within the firefighter clothing makes faster skin burns. The objective of this study is how the wet condition within a firefighter clothing makes faster heat transfer from feeling pain and to being 2^nd degree of skin burns relative to the dry condition in case of routine firefighting operation in a building (up to 20 kW/m²). Aramid station wear and cotton underwear, generally used by a Japanese firefighter, have been selected and cut 0.15 m x 0.15 m to attach an ISO 9151 copper sensor. A cone shape electric heater, which produces 12 kW/m² to 20 kW/m², was used to heat the fabrics. Scenario of fabrics are that (1) wet station wear and dry underwear, (2) wet station and wet underwear, (3) dry station wear and wet underwear, and (4) dry station wear and dry underwear. Evaluation method was by a heat transfer index (HTI) by ISO 9151. The time to rise temperature of 12 and 24 °C (HTI₁₂ and HTI₂₄), and heat transfer rate (dT/dt) were investigated for above four scenarios. The result shows that there was significant impact by condition of station wear, but little impact by underwear. In heat transfer rate (dT/dt) analysis, for the situation of feeling pain to the 2^nd degree of skin burns (from HTI₁₂ to HTI₂₄), heat transfer rate was about 50% higher relative to the dry station wear condition. This result indicates that it is possible to be 2^nd degree of skin burns easily as soon as a firefighter feels the pain, if he/she wears wet station wear.

Abstract: In this study, the effect of different undergarments on micro-climate environment under anti-static dust-free clothing was investigated. Five male undergraduates participated in wear trials conducted in a climate chamber of 24 ± 1°C and 60 ± 5%RH, three undergarments of different materials were worn under an antistatic dust-free overall respectively. While subjects doing mild exercise, the temperature and relative humidity under the undergarment was measured at chest, and the skin temperature at arm, chest, thigh and calf were measured. It was found that undergarment made of plain woven fabric was the best to keep the relative humidity on skin surface low and mean skin temperature stable during mild exercise among three undergarments of different materials. It was demonstrated that hydrophilic fiber might not the best material of undergarment for protective clothing, knitted fabrics which have more volume to hold water might not be good either. It was showed that materials absorb water and moisture and quick dry is suitable to undergarment for protective clothing.

Abstract: High-temperature protective clothing is one kind of the most widely used protective clothing. This research regarded the thermal protective clothes for labors work in high-temperature metallurgical steel iron workshop as the study object. In the form of questionnaires, according to the actual high temperature working environment, we extracted the necessary wear performances for thermal protective clothing as factors on the questionnaire survey. Then we issued survey questionnaires to labors work in different workshop in a major metallurgical steel iron industry. By analyzing the statistical information with SPSS, we discussed the subjective performances of the overalls mainly from the protective performance and comfortable performance. The results indicated that the pure cotton overalls, which were used for the investigated metallurgical steel iron enterprise, fall short of the satisfaction requirements in all aspects, for example, thermal insulation, flame retardant, moisture vapor transmission, abrasion resistance and strength. As a result, the study could point out the drawbacks of the high-temperature overalls for ironworkers used in present. This research could have a certain guiding significance in the development and improvement on performances of high-temperature protective overalls. To sum up, this paper could provide scientific basis for future researches to improve the functionalities and wearabilities of the high-temperature protective overall for the ironworkers.

Abstract: Under high temperature condition, determination of phase transition temperature and combination of PCM layer with the other layers affect the thermal buffering properties of the protective clothing. In this paper, Body-clothing-environment temperature gradient was analyzed. Related data was obtained from the dressing experiments. After that, phase transition temperature range of the protective clothing was determined. Temperature and humidity of human skin and microclimate were tested respectively with different positions of PCM layer. Finally, the optimization layer configuration was suggested.

Abstract: Fiber air dispersion system (FADS) is a new flexible ventilation terminal in ventilated areas. It can be used in both air transmission and air diffusion. The cloth duct made of flame retardant polyester is critical. The conditioned air can be dispersed to environment by not only micro pores in the fabric but also slot and orifice on the fabric. The micro-pores in the fabric exist in the yarns and fibers. The laser can be used to cut the slot and orifice on the fabric. They can be designed based on the application. In this paper, air dispersion models and basic characteristics of fiber air dispersion system were introduced. Based on computational fluid mechanics theory, the flame retardant cloth ducts (FRCD) is regard as an isotropic porous media. The air dispersion physical model for micro porous that sends the air to the environment was established. And the Carman-kozeny equation was used in this model, which was described the airflow field in the FRCD. Finally the airflow field in the FRCD was numerically simulated with the FLUENT software based on the finite element method. The air flow resistance of the fabrics was calculated by the Darcy model.

Abstract: In low temperature environment, the lack of a proper thermal protection can cause human body frostbite, or even cause death. In this paper, the computational method of theoretical relationship between the phase change materials content in protective clothing, protective time and the working environment temperature was proposed when took into account the comfort requirement of human bodies, clothing thermal properties and heat loss through clothing system. This theoretical model could be used to predict the relationship between the protective material content and the protection time of phase change protective clothing. Experimental results show good accordance with the theoretical prediction.

Abstract: .In order to design better anti-radiation and electromagnetic shielding fabric and the clothing and makes it maintained better of electromagnetic shield effectiveness, the influence of radiation source, radiation distance, anti-electromagnetic radiation material, fabric structure, gap size, holes area, clothing exposed area as well as the tunnel effect and so on the fabric radiation protection performance were comprehensively discussed in this article. As well, according to these influence factor analysis the regular conditions that the electromagnetic shielding fabric and garment design should be meet. The analysis result indicated that the shielding effectiveness of the fabric was decreased with the increase of the radiant frequency, the fabric slit size, the hole area and enhanced with the growing of the metal content, the organizational structure close degree as well as the radiation distance.In the case of the equal shielding effect, the bigger exposed area leads weaker electromagnetic shielding effectiveness and if the exposed area oversize can cause the shield effect vanished. Also the clothing shield potency was related to the opening radius, the length, the inside and outside dielectric constant, the permeability of the shirt or cuff. The comprehensive effectiveness of electromagnetic shielding fabrics will be gradually improved if they can meet these regular conditions continually.