北美地区杨树木材利用现状与前景

过去20多年, 北美地区的杨树已经从杂草树种转变为产生巨大经济效益的用材林树种, 杨树木材因其具有较高纤维素含量和较低的木质素含量, 适合用作纸浆和纸制品的原料。杨木制浆方法有机械法、化学法、半化学法和化学机械法, 杨木浆可以作为高级纸、纸板、新闻纸和包装纸。杨木牛皮纸浆与针叶材牛皮纸浆混合, 具有良好的成纸性能, 透明度高, 适合制作高级用纸。杨木也是传统的锯材、单板和胶合板工业的原材料, 用来生产锯材、单板、胶合板、木质复合板、包装箱、集装箱、火柴杆和筷子等。最近10年杨木定向刨花板和结构复合板产量显著增加, 利用前景广阔。从资源生产的角度来看, 在改良木材化学组成、纤维质量和自然耐久性等方面进行木材性质改良的转基因杨树研究取得了长足进展。从资源利用角度来看, 高价值的工程复合板和高得率的纸浆和纸产品将会在未来发展中快速增长。

Achievements in the Utilization of Poplar Wood in North America and Guideposts for the Future

From an early status as a"weed tree",poplar has become an important commercial genus in North America during the past 20 years.The wide and varied uses of poplar wood now include pulp and paper,lumber,veneer,plywood,composite panels,structural composite lumber,containers,pallets,furniture components,match splints and chopsticks.The high cellulose and relatively low lignin content make poplars well suited for pulp and paper products.The wood can be pulped by all commercial pulping methods,such as mechanical,semi-chemical,sulphate and sulphite processes.Poplar pulps are utilized in fine papers,tissues,paperboard,newsprint and packaging papers.Poplar kraft pulps,when blended with softwood kraft,are particularly well suited for fine paper manufacture because of inherently desirable properties,such as excellent sheet formation,high opacity,good bulk and good printability.While poplar wood continues to be an important raw material in the traditional lumber,veneer and plywood industries,the most remarkable recent achievement in poplar utilization is the phenomenal growth of the oriented strandboard and structural composite lumber industries in North America during the past decade.The future for poplar utilization is bright.On the resource production side,opportunities for genetically modifying important wood properties,such as chemical composition,fiber quality and natural durability of wood,can now be realized.On the resource utilization side,high-value engineered composites and high-yield pulp and paper products will represent the strongest growth sectors for poplar fibre during the coming decades.