纤维原位合成硅酸钙及其造纸性能

In-situ Synthesis of Calcium Silicate in Fiber and its Properties in Paper Making

研究了以粉煤灰脱硅液和石灰乳为原料,在针叶木浆纤维的细胞腔壁以及分丝帚化形成的网络空间内原位合成硅酸钙的工艺条件,并利用纤维原位合成硅酸钙复合纸浆抄造文化用纸.实验确定该方法制备文化用纸的最佳工艺条件:纤维在脱硅液内的润浸时间为4,h,纸浆打浆度40,°SR,粉煤灰脱硅液中Si O2质量浓度50.0,g/L,石灰乳中有效钙(Ca O)质量浓度185.0,g/L,搅拌速率400,r/min,反应温度90,℃,反应时间60,min.在此条件下,文化用纸中的填料留着率可达到80%,以上,强度符合复印纸国标要求.采用扫描电子显微镜-能谱(SEM-EDAX)、X射线衍射仪(XRD)、红外光谱(IR)对合成产物及文化用纸的结构、性能进行了表征.结果表明,硅酸钙在纤维细胞腔和细胞壁以及分丝帚化形成的网络空间内均有生成.

This paper reports on fiber in-situ synthesis of calcium silicate from sodium silicate solution, lime milk, and fiber, for usage in fine paper-making. The /n-fiber synthesis technique was used to load man-made calcium silicate into paper. The experiments determined the optimum conditions for papermaking as follows： in pre-processing, fiber should be immersed in silicon solution for 4 h, pulp freeness 40 °SR, the SiO2 concentration of the silicon solution 50.0 g/L, the effec- tive calcium concentration in the milk of lime 185.0 g/L, stirring speed 400 r/min, the reaction temperature 90 ℃, and the reaction time 60 min. Under these conditions, the filler retention rate in fine paper could reach more than 80%, and the qual- ity of the paper is in line with the national standards for copy paper. Scanning electron microscopy and spectroscopy （SEM- EDX）, X-ray diffraction （XRD）, and infrared spectroscopy （IR）were used to analyze the paper products and their struc- tures. The results showed that the calcium silicate was generated within the cell lumen, cell wall, and other open space of the fibers.