无胶生态树皮板的研究现状及展望

树皮是一种量大且可再生的天然生物质纤维材料,但是一直未被科学有效地利用。目前树皮的利用途径主要有物理利用和化学利用两种。随着木材资源的短缺,人们愈加重视树皮作为人造板原料的物理利用途径。笔者总结了国内外无胶生态树皮人造板的研究现状,重点介绍了无胶树皮板的制造技术和研究方法。虽然国外学者对无胶生态树皮板进行了诸多研究,但是依然停留在实验室研究阶段,相对于木质生态板,树皮板价格上并无优势,因此产业化尚未开展; 而国内学者对此领域的研究才刚起步。树皮化学成分和纤维形态、树皮单元尺寸、预处理和热压工艺,尤其是热压温度对无胶树皮板的物理力学性能影响较大,在今后的研究中应加以重视。此外,无胶树皮板胶合机理的研究主要有热重分析、差示扫描量热分析法、傅里叶变换红外光谱分析法和扫描电子显微镜分析法等,在今后的研究中可供借鉴选用。最后对无胶树皮板的研究方向和发展前景进行了展望。
As one of the abundant and renewable natural bio-based materials, bark is underutilized economically and scientifically. Up to now, there are mainly two ways to utilize bark, namely physical methods(e.g. biofuel, plant culture substrate, bark compost, wood composites, soil conditioner, and cork products)and chemical methods(e.g. animal fodder, activated carbon and adsorbent, extracted tannin as wood adhesive and pharmacy). Along with the shortage of wood resources, as one special material for panels, bark has been received a glowing attraction recently. This research mainly focused on the global research status of binderless ecological bark-based panels and reviewed the manufacture process and methodologies of the bark-based panels. The results showed that, although the foreign scientists have conducted many studies on the binderless bark-based panels, this technology has not been commercialized owing to its high cost in comparison with ecological wood-based panels. Moreover, the similar studies of this technology in China are limited or just nascent. Based on the previous literature, it was found that the bark chemical compositions, fiber configurations, bark element size, pre-treatment and hot-pressing process especially for hot-pressing temperature had a great influence on the physical and mechanical properties of the final products. In addition, the bonding mechanism of bark-based panels was examined using thermogravimetric analysis, differential scanning calorimetry method, Fourier transform infrared spectroscopy and scanning electron microscope analysis, which would provide a scientific foundation for the further research. Finally, the development and future research directions of binderless ecological bark-based panels were discussed