عنوان مقاله [English]
Utilization of long fiber chemical pulp to enhance the strength properties of mechanical and chemi-mechanical pulp is served as a common approach by the papermakers. Therefore softwood long fibers were exposed to chemical modification by cationic agent, EPTMAC, with the aim of reducing its consumption. Then, the cationised fibers were mixed with CMP pulp with given ratios and the handsheets were made. To evaluate cationization effect on long fiber consumption, the burst strength, tensile strength, tear strength and the degree of fines retention were determined. The results indicated that mixing cationised long fibers with CMP leads to enhance strength properties and fines retention, however high level of cationisation especially at high mixing ratio had partially negative effect on tear strength of hand sheets. The properties of hand sheets were improved significantly at 5% (based on O.D fiber weight) cationic agent. Generally, by cationic modification of long fibers by EPTMAC, their consumption can be reduced during mixing with CMP, while acceptable strength properties of resulted sheets are achieved too.