牛皮卡纸用针叶木硫酸盐浆蒸煮技术的比较

Comparison of cooking technologies for production of softwood kraft liner pulp

作为瓦楞纸板的底层和顶层材质,牛皮卡纸在美国及其他世界各地是主要纸产品之一,并且是一个在制浆造纸领域有着发展前景的产品。然而,多年来,牛皮卡纸的制浆技术发展有限,这是由于大多数国家瓦楞纸板的标准有定量要求而没有强度要求。随着222/41规则的出台,在美国这种只看定量不关注强度的情况有所改善。近来,人们研发了一项新的制浆技术,采用该新蒸煮技术蒸煮针叶木能在较高的硬度下蒸煮成浆,并且使纤维得到很好的分离,浆渣率也低。将采用新蒸煮技术与传统蒸煮技术蒸煮的牛皮卡纸用浆以卡伯值进行对比,以比较两种蒸煮浆的蒸煮质量。研究中发现,两种蒸煮浆最大的不同是,采用新蒸煮工艺,其H因子要求低和蒸后浆强度增加,这两项指标通常用来衡量浆的抗张吸收能量,新蒸煮技术要求相对低的H因子和蒸后浆强度增加,这有利于牛皮卡纸用纸浆制浆技术的发展。

Kraft liner, used as the top and bottom layers in corrugated board, is one of the major paper products in the United States and worldwide and is a long-term growth business area for the pulp and paper industry. However, for many years pulping development for kraft liner has been limited. The lack of development may be because corrugated board standards in many countries have specified basis weight and not strength demands on the corrugated board. With the modifications of Item 222/Rule 41, the situation in the United States has changed. Recently, a new cooking technology has been developed enabling defibration of softwood pulps at considerably higher kappa number with low reject content. Pulp quality as a function of kappa number has been evaluated for this new cooking technology compared to pulp produced using a conventional kraft liner cooking technology. Lower H-factor demands and increased strength, measured as tensile energy absorption, were the most important differences found between the two cooking systems in this study. A new cooking technology may contribute to development of pulping for kraft liner. Key words： low-temperature impregnation; a two-vessel steam/liquor phase digester system; tensile energy absorption index; pulp sheet density