锯末粉真空绝热板的制备及性能

当前,真空绝热板主要采用成本较高的气相二氧化硅或不可再生的玻璃纤维作为芯材,为减少真空绝热板的成本,提高木材锯末粉的高值化利用,以木材锯末粉为原料、环氧树脂为胶黏剂制备真空绝热板,研究了木材锯末粉粒度(30～60,≥60～100和≥100～300目)和不同芯材密度(0.2,0.3,0.4和0.5 g/cm3)对真空绝热板性能的影响。试验结果表明,当密度为0.3 g/cm3时,随着锯末粉目数的增加,芯材静曲强度仅增加5%,因此,锯末粉目数对芯材静曲强度影响不明显。当锯末粉粒度为≥100～300目时,随着芯材密度的增加,芯材静曲强度增幅可达132%,因此,芯材密度对静曲强度影响明显。在满足自身成型的基础上,密度为0.2 g/cm3的芯材静曲强度可满足欧洲建筑保温材料的要求。当木材锯末粉目数小于300目且密度为0.3 g/cm3时,随着木材锯末粉目数的增加,芯材的平均孔径减小,芯材孔隙率增加,导热系数减小; 当木材锯末粉粒度为≥100～300目时,随着芯材密度的增加,芯材的平均孔径减小,芯材孔隙率减小,导热系数增大; 当木材锯末粉粒度为≥100～300目、芯材密度为0.2 g/cm3时,木材锯末粉真空绝热板的导热系数最低,仅为0.010 5 W/(m？K)。
Vacuum insulation panels(VIP)is regarded as one of the most promising solutions for high performance thermal insulation, and the insulation performance of VIP mainly depends on the core material. At present, the VIP mostly uses the high cost of fumed silica or non-renewable glass fiber as the core material. In order to reduce the cost of VIP and increase the utilization of wood sawdust, the VIP was prepared with wood sawdust as raw material and epoxy resin as adhesive. The influence of particle size(30-60 mesh, ≥60-100 mesh and ≥100-300 mesh)of wood sawdust and the density of core material(0.2 g/cm3, 0.3 g/cm3, 0.4 g/cm3 and 0.5 g/cm3)on the thermal insulation performance of wood sawdust VIP was examined. The results showed that, when the density of the core material was 0.3 g/cm3, with the increase of the particle size of core material, the modulus of rupture(MOR)of the core material increased by only 5%, demonstrating that the particle size of the core material had no obvious effect on the MOR. When the particle size of the core material was ≥100-300 mesh, with the increase of the density of the core material, the MOR of the core material increased by 132%, indicating that the density of the core material had an obvious effect on the MOR. When the density of the core material was 0.2 g/cm3, the MOR of the core material could meet the requirements of the European standard for the insulation materials in the construction application. When the particle size was lower than 300 mesh and the density of the core material was 0.3 g/cm3, with the increase of wood sawdust powder mesh, the average pore size of the core material decreased, the porosity of the core material increased, and the thermal conductivity decreased. When the particle size of wood sawdust was ≥100-300 mesh, with the increase of the core material density, the average pore size and the porosity of the core material decreased, and the thermal conductivity increased. When the particle size of wood powder was ≥100-300 mesh and the core material density was 0.2