Verification study on the performance of binder-less insulation panel made of wood shavings for wooden frame houses

本研究开发的保温板是由木屑压成密度为110 kg/m^3的垫子组成的，没有任何粘结剂。这块垫子是用塑料薄膜覆盖的，起到了防潮的作用。在本研究中，对防火安全和隔热性能进行了调查。用全尺寸厚的木框墙进行的防火试验表明，填充我们的保温板的测试墙比填充玻璃纤维的墙具有更高的隔热性能。这是因为木屑的炭化会产生水，由于塑料薄膜的存在，其中一些水会留在我们的面板后表面附近，因此，水会消耗汽化能量，导致温度保持在低于100℃左右。隔热性能相当于日本建筑标准法规定的60分钟准防火性能。虽然我们的人造板的导热系数大于玻璃纤维，但在25℃下测得的热扩散率在0.4mm2/S之间，由于更高的热容，大约是玻璃纤维的一半。对一栋单层实验房进行的保温性能测试表明，无论是冬季还是夏季，室内温度的周期性变化都小于使用玻璃纤维绝缘体时的周期性变化。这是因为木屑的储热能力高于玻璃纤维。此外，即使在冬季，当面板表面之间的温差上升20℃时，我们的面板的较低温度表面也没有发现蒸汽凝结。

The insulation panels developed in this study are composed of wood shavings compressed into a mat with a density of 110 kg/m^3 without any binder. This mat is lapped with plastic film that works as a damp proof course. In this research, fire safety and thermal insulation capacity were investigated. Fire tests conducted with a full-scale-thick wooden frame wall revealed that the test wall filled with our insulation panels had a higher heat shielding performance than the walls filled with fiber-glass. This is because charring of wood shavings generates water and some of it remains near the rear surface of our panels due to an existence of plastic film, and consequently, the water consumes vaporization energy and resulted in keeping a temperature lower than around 100 ℃. The heat shielding performance was found to have a quality equivalent to the 60-minute quasi-fireproof performance stipulated in the Building Standard Law of Japan.Although thermal conductivity of our panel is greater than that of fiber glass, thermal diffusivity measured at 25℃ ranged from 0.4 to 0.5 mm^2/s and are about half the value of fiber-glass due to higher heat capacity. Thermal insulation capacity tests conducted with a one-story experimental house revealed that the cyclic change of room temperature in both winter and summer was smaller than when fiber-glass insulators were used. This is because the heat storage capacity of wood shavings higher than fiber-glass. Furthermore, no vapor condensation was recognized on the lower temperature surface of our panel even when temperature difference of 20℃ rose between panel surfaces in winter.