Research Of Fireproof And Heat-insulation Composite Fabrics With Shape Memory Alloy

According to the instantaneous high-temperature fire environment that firefightersmay face, a kind of composite fabrics which could provide adequate protection for specialparts of the body (such as the back) in such environment was researched. The fabric is notonly fire protection and heat insulation, but is also very light. From outside to inside, thefabric is composed of a fireproof outer layer, a reflective layer, a heat-insulation layer and aflame-retardant inner layer. In this paper, theoretical analysis was used to establish therequirements of the composite fabrics and each layer. According to the requirements,appropriate materials for each layer were selected, and the relative performance of thematerial was tested. The application of air layer and silica aerogels as the heat-insulationlayer was proposed. Fireproof and heat-insulation performance of several differentcombinations were studied. Finally, ANSYS software was applied to stimulate theheat-transfer model for the fabrics. A kind of composite fabrics with excellent performanceof thermal insulation and fire protection was obtained. The contents and conclusions of thispaper can be summarized as following four aspects.First, each layer’s performance requirement of the composite fabrics was studied. Therequirement for the using temperature and limiting oxygen index of the fireproof outerlayer, reflectivity of the reflective layer, insulation layer’s using temperature and thermalconductivity, flame-retardant layer’s using temperature and flammability were defined.Through theoretical analysis, appropriate materials were selected as the layers of thecomposite fabrics and their relative performance was tested. The results showed that basaltfiber could withstand high temperature above800℃and have insulating properties, whichis suitable for the outer layer; aerogels have a low-density, high using temperature andpermanent insulation performance, which is suitable for thermal layer material; shapememory spring’s of action temperature is about45℃, with a certain degree of elasticity, can form a20mm insulating air layer; PSA fabric has high using temperature, good flameretardancy and thermal stability, can be used as the flame-retardant inner layer.Second, the composite fabrics’ performance requirements were established. Thethermal protective performance (TPP value) is required greater than60. The fireproof andheat-insulation is defined as: after heated by800℃flame for60seconds cold facetemperature of the fabric is not higher than50℃, after heated by450℃flame for180seconds cold face temperature of the fabric is not higher than50℃. Instantaneousthermal-insulation composite fabrics with shape memory alloy and the permanent-insulation composite fabrics with aerogels were studied respectively, including theircombination way, thermal protective performance and heat insulation performance.ORIGN analysis software was used to analysis the experimental data. The results showedthat: instantaneously insulate composite fabrics’ TPP value is47.6, the cold facetemperature reached to50℃after burning on the450℃flame for20seconds,, the coldface reached to50℃after burning on the800℃flame for15seconds;permanent-insulation composite fabrics’ TPP value is greater than60, buring on the450℃flame for140seconds the cold face temperature reached to50℃, burning on the800℃flame for44seconds the cold face temperature reached to50℃.Third, the composite fabrics with shape memory spring and aerogels were studied,including the combination way, heat-insulation performance and fireproof performance.And the obtained data was anlysised by using ORIGN analysis software. The resultsshowed that: burning on the450℃flame, the temperature of the composite fabrics’ coldface was never higher than50℃, burning on the800℃flame for90seconds the compositefabrics’ cold face temperature reached to50℃. TPP test showed the thermal protectionperformance is better than60, both the thermal protection performance and fire-protectionperformance are excellent.Fourth, the heat-transfer model of the fabrics was stimulated by ANSYS. The resultsof simulation and results of experimental matched well, especially single heat transfermodel for aerogels. The model is basically effective.