纤维素纤维-填料共磨体系下纸张强度与光学性能的双重改善机理研究

Development of new fillers and novel filling technology is one of the hot topics in paper industry. Currently, there is no low cost and effective way to increase paper strength without sacrificing optical properties at a given filler content. Our previous study found that not only paper strength were improved but also paper optical properties can be noticeably increased by co-refining of filler and fiber. However, current theory cannot explain the phenomenon. Therefore, based on the interaction between filler and fiber during refining, three hypotheses, i.e. synergistic grinding, composite reinforcement and lumen loading are proposed to explain the improvement mechanism of the paper strength and optical properties. In this project, the fragmentation/aggregation dynamics and the formation and evolution of fiber-filler composite are investigated. The mathematics model of paper structure and properties will be built based on paper void volume, light scattering coefficient and filler distribution. The results can enrich the theory related to the strength of filled paper and help to develop novel filler technologies.

新型填料及加填技术的开发一直是国内外造纸工业的研究热点之一。当纸张填料含量一定时，采用现有加填方法在改善纸张强度性能的同时，其光学性能往往会有不同程度地下降。前期研究发现，与现有加填方式相比，将填料和纤维在磨浆机中共同磨浆不仅可改善纸张的强度性能，还可大幅提高光学性能。然而，现有理论却无法解释该现象。因此，本课题从磨浆过程填料与纤维的相互作用出发，提出“协同助磨”、“复合增强”以及“胞腔加填”等假设，采用现代仪器分析手段，对纤维素纤维-填料共磨体系下填料破碎/聚集动力学以及纤维-填料复合结构的形成、演变规律进行研究，通过分析纸张孔隙率、光散射系数、填料分布等结构参数，建立加填纸结构与性能模型，揭示共磨体系下纸张强度与光学性能的双重改善机理。研究结果可丰富现有加填理论，为新型造纸填料和高加填技术的开发提供理论依据。

无机矿物填料作为纸张生产的第二大原料广泛用于造纸工业的生产实践中。当纸张填料含量相同时，采用现有浆内加填的方法在改善纸张强度性能的同时，其光学性能会有不同程度的下降。本课题研究发现，与传统加填方式相比，将填料和纤维共同磨浆不仅可改善纸张的强度性能，还可提高纸张的光学性能。项目从磨浆过程中填料与纤维的相互作用出发，构建了不同纤维素纤维-填料共磨体系，揭示了共磨体系下，纸张强度性能、光学性能与结构性能等纸张性能参数及浆料湿部和组分的变化规律，探究了共磨过程中纤维与填料之间发生的“协同助磨”、“复合增强”以及“胞腔加填”等机理，揭示了共磨体系下纸张强度与光学性能的双重改善机理，相关结果可为开发新型高加填纸技术提供理论和技术依据。