Influence of Thermal Shrinkage on Protective Clothing Performance during Fire Exposure: Numerical Investigation

Abstract

The thermal shrinkage of protective clothing during fire exposure plays a crucial rule in reducing the clothing protective performance. The transversal reduction in the fabric perimeter around the body due to the fabric thermal shrinkage causes a dynamic reduction in the air gap between the clothing and the body. This leads to a dynamic change in the heat transfer modes within the gap. Despite of its influential effect on the clothing performance, the thermal shrinkage of protective clothing during fire exposure has not been yet addressed in the literature. This can be attributed to the absence of a gap model that can capture the reciprocal change in heat transfer modes within the gap due to clothing shrinkage. This paper develops a finite volume model to investigate the influence of the fabric thermal shrinkage on protective clothing performance. A special attention was drawn to the model of the air gap between the clothing and skin as it responds directly to the clothing thermal shrinkage. The influence of a variation in the fabric shrinkage rate and the overall reduction in the fabric dimensions was investigated. The paper demonstrates that the clothing protective performance continuously decreases with the reduction in the fabric dimensions while the decay in the clothing protective performance is limited to small shrinkage rates of the fabric. Moreover, this decay in the clothing performance vanishes at high shrinkage rates of the fabric.

Development of a multi‐layered skin simulant for burn injury evaluation of protective fabrics exposed to low radiant heat

“…For comparison, the corresponding properties of human skin are also presented which are derived from international standards (forearm only), 12,24 researches from in vivo studies, [28][29][30][31][32] as well as studies in thermal protective clothing research field. [33][34][35][36][37][38] The thickness of S170 could be well controlled with a precision of less than 5 μm. The pre-experimental results showed that there was a linear relation between the set thickness before curing and the resulting thickness after curing.…”

“…The measured properties of S170 and S184 are shown in Table . For comparison, the corresponding properties of human skin are also presented which are derived from international standards (forearm only), researches from in vivo studies, as well as studies in thermal protective clothing research field …”

Termal Koruyucu Giysilerin Koruma Performansı Üzerinde Hava Boşluklarının Etkisi

“…Termal koruyucu giysilerin yoğun ısıya maruz kalmaları neticesinde giysilerde ısıl büzülme oluşabilmekte ve bu büzülme ile vücut etrafında sarılı olan kumaş çapında enine yönde bir azalma gerçekleşerek, giysi ve vücut arasında oluşan hava boşlukları dinamik olarak küçülmektedir [51]. Li ve diğerleri (2015) ani yanma durumunda oluşan ısıl büzülmeyi etkileyen faktörleri belirlemek için yapmış oldukları çalışmalarında ısıl büzülmenin aleve maruz kalma koşulları, kumaş özellikleri, giysi bedeni ve vücudun hareket durumundan etkilendiğini belirlemişlerdir.…”

“…Çalışma sonucunda giysinin aleve maruz kalması neticesinde koruma performansının kumaşın boyutlarında meydana gelen azalmaya bağlı olarak azaldığı tespit edilmiştir. Ayrıca giysilerin koruma performansı üzerinde giysi çapındaki azalmanın kumaş büzülme hızına göre daha etkili olduğu gözlenmiştir [51].…”

Quantitative assessment of the thermal stored energy in protective clothing under low-level radiant heat exposure

“…2–4 The failure of protection observed in emergency conditions should be partly due to thermal degradation or thermal shrinkage of protective clothing that may destroy the integrity of the clothing. 5,6 However, it is reported that skin burn commonly occurs in the low-level thermal radiation ranging from 5 to 20 kW/m 2 . 7,8 Contrary to emergency conditions, exposures to low-level thermal radiation are generally not sufficient to degrade the protective clothing.…”