Basic research of laser incising to develop fire resistive glulam and cross laminated timber made of Japanese cedar

结果如下：用功率为1kW、脉宽为0.1s的板条CO_2激光器在日本柳杉叶片上可形成直径小于2mm的小孔。激光通过小孔可以使阻燃剂均匀地浸渍到杉片上，且变化较小。集成材由承重部分（未经处理的集成材）、防火熄灭部分（浸渍阻燃剂）和表面部分（未经处理的层板）三个区域组成，通过了一小时的防火性能测试，并获得了政府认证。2013年5月，在东京市中心的防火区，第一座主柱和主梁由一小时防火胶合板组成的建筑完工。

The results are follows; a pinhole whose diameter is less than 2 mm could be made in lamina of Japanese cedar by the slab CO2 laser with the 1 kW power and 0.1 sec pulse duration. The fire retardant could be impregnated evenly with less variation to Sugi lamina through pinholes by laser. The glulam consists of three zones such as load-bearing part (untreated glulam), fire-dieout part impregnated fire-retardant chemicals and surface part (untreated lamina) could pass the one-hour fireproof performance test and got the certificate by the government. The first building whose main column and beam were consisted of the one-hour fire proof glulam was completed in fire protection district of downtown Tokyo in May2013.