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Research and Development on Wood-Carbon Composites from Charcoal of Wood Thinnings as an Electromagnetic Shield and Fire Resistive Material

木材间伐木炭木炭复合材料作为电磁屏蔽和防火材料的研究与开发

基本信息

批准号：
03556025
负责人：
ISHIHARA Shigehisa
金额：
$ 10.24万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

In order to develop new materials utilizing wood thinnings, residues and wastes from wood industries, forestry wastes, and unused wood species, research and development studies on carbon composites (carbon-phenolic formaldehyde resin sphere) from charcoal of wood materials and bamboo were conducted. Wood charcoals carbonized at a high temperature were highly electric conductive, highly thermal conductive, highly resistive to heat and fire, and were neither melted nor softened under red heat. Various kinds of wood charcoal were used in the manufacture of electromagnetic shield and fire resistive composites.Relationships between carbonizing temperature and the fire resistive composites were examined and discussed. Fire resistivity of the carbon composites were tested by an oxygen index method in accordance with the Japan Industrial Standards(JIS) K 7201, by a burn-through method, and by cutting with oxygen-acetylene torch. Electromagnetic shielding property of the composites was tested b … More y a dual chamber method in accordance with ASTM ES7-83. Fire resistive and shielding effects of the carbon composites from wood and wood components were improved by the increase of the carbonizing temperature.The low combustibility of the composite boards from charcoal carbonized at 800ﾟC or above was due to the graphitization of charcoal. Fire endurance of the composite boards was improved by time delay in the burn-through method and this is due to the resistivity, isotropically high thermal conductivity and slow oxidation of charcoal graphatized by high temperature carbonization.The high electromagnetic shielding efficiency of the composite boards from wood charcoal carbonized at 1200ﾟC or above was also due to the graphitization of the charcoal and isotropically high electric conductivity of the composite boards.The electromagnetic shielding and the fire resisting performance of the carbon-composite-powder overlaid particleboards were evaluated in full-scale test in accordance with US MIL STD 285 and JIS A 1304,respectively.The fire endurance of the carbon-composite overlaid particleboard was improved both at time delay ignition and temperature rise at the unexposed surface when compared with the controls of the same board thickness and density. The electromagnetic shielding effectiveness was over 40 dB( - 70dB) against electric field, which satisfied a standard as shielding materials for partitions and enclosures of office buildings and computer aids.Wood particles metalized by an electroless plating were found suitable as a raw core material for the electromagnetic shield carbon-wood composites. Less

为了开发利用木材间伐物、木材工业的剩余物和废弃物、林业废弃物和未使用的木材的新材料，进行了由木质材料的木炭和竹子制成的碳复合材料（碳-酚醛树脂球）的研究和开发。在高温下煅烧的木炭具有高导电性、高导热性、高耐热性和耐火性，并且在红热下既不熔化也不软化。将不同种类的木炭用于制备电磁屏蔽材料和阻燃复合材料，研究和讨论了炭化温度与阻燃复合材料的关系。通过根据日本工业标准（JIS）K 7201的氧指数法、通过烧穿法和通过用氧-乙炔炬切割来测试碳复合材料的耐火性。B测试了复合材料的电磁屏蔽性能 ...更多信息 y根据ASTM ES 7 -83的双室法。提高炭化温度可提高木质及木质构件炭复合材料的阻燃性和屏蔽效果，而800 ℃以上炭化炭复合材料的低燃烧性是由于炭的石墨化所致。在烧穿法中通过时间延迟提高了复合板的耐火极限，这是由于电阻率，高温炭化石墨化的木炭具有各向同性的高导热性和缓慢的氧化性，在1200 ℃以上炭化的木炭复合板具有高的电磁屏蔽效能也是由于木炭的石墨化和各向同性的高导电性根据US MIL STD 285和JIS A 1304在全尺寸试验中评价碳-复合-粉末覆盖刨花板的电磁屏蔽和耐火性能，碳纤维复合材料的耐火极限复合贴面刨花板与对照板相比，在未暴露表面的延迟点火和温升方面都有所改善厚度和密度。结果表明，该复合材料的电磁屏蔽效能大于40 dB（-70 dB），可作为办公楼隔墙、围护结构和计算机辅助设备等的屏蔽材料。少