Flame retardance of insolubilized silica inside of wood material

Abstract

Beech wood boards were studied with a cone calorimeter. As the specific density of these materials is greater, the total amounts of CO and CO 2 produced were bigger than values measured on spruce specimens. Also, the shape of the heat release rate (HRR) curve was different as its second peak was bigger than the one observed on spruce wood. It was shown that impregnation of wood with water solutions of H 3 BO 3 resulted in decreased HRR values with increasing acid concentrations. Mass loss and CO and CO 2 production rates also decrease in the same way. Impregnation with water-soluble NaOH-silica resulted in improved data, when compared to untreated specimens, but were not better than those obtained with H 3 BO 3 . Simple mixing of both fire retardants gave no improvement, nor was the two-step impregnation with drying effective after the first step. When the second step-treatment with acid was followed without drying after impregnation with NaOH-silica in the first step, then improvement was evident. This is explained by precipitation of the silica content inside the material when the NaOH was neutralized with H 3 BO 3 , which could penetrate inside when the material was not dried before the second step. The improvement resulted in lower smoke production and longer times to ignition.

Mineralization of wood by calcium carbonate insertion for improved flame retardancy

“…In mineralized wood, both peak HRR are substantially decreased and shifted to longer exposure times (Table 1), which indicates a lower fire growth rate and enhanced char stabilization. In essence, the PHRR values are reduced to a similar extent as in other fire-retardant systems reported in the literature (Simkovic et al 2005;Simkovic et al 2007;Hagen et al 2009;Grześkowiak 2012;Mahr et al 2012). As the mass loss values of unmodified and mineralized woods are comparable (Table 1), it can be assumed that the improved fire retardance of mineralized wood results from a combination of both physical and chemical effects.…”

Smoke Hazard Assessment of Cypress Wood Coated with Boron/Silicon Sol Compounds

“…목재는 화재 또는 고강도 열원과 접촉 시 열분해 및 연 소에 취약하여 목재 방염성의 개선이 더 중요 해지고 있다. 목재의 방염성을 개선하기 위한 많은 연구가 수행되었지만 표면 코팅의 함침, 혼입 및 형성을 포함한 세 가지 주요 접 근법이 실제로 효율적이고 실현 가능한 것으로 간주되고 있다 (1)(2)(3) . 실외 및 실내용 비독성, 내구성, 안전 및 내화성 목재 제품의 개발이 매우 중요하며 목재의 보호를 강화하 기 위해 최근 수십 년 동안 다양한 유기 및 무기 화합물이 연구되었다.…”

Combustion behavior of Scots pine (Pinus sylvestris L.) sapwood treated with a dispersion of aluminum oxychloride-modified silica

“…There are few reports concerning the fire properties of silica-treated woods (Acton 2013). Sodium silicate (water glass) may serve as a fire retardant for wood (Fuchs 1825;Šimkovic et al 2005) and this method was recently patented (Slimak and Slimak 2014). The mode of action is due to NaOH-catalyzed charring of wood and formation of a silicate barrier.…”