The purpose of this study was to compare plate and conical refiner fillings in refining of softwood and hardwood pulp fibers. Contrary to expectations, better tensile strength values were achieved when BSW was refined...The purpose of this study was to compare plate and conical refiner fillings in refining of softwood and hardwood pulp fibers. Contrary to expectations, better tensile strength values were achieved when BSW was refined with conical fillings and the development of strength was found to be insensitive to variations in refining intensity. A bar microprofile was measured with the aid of a profilometer. The leading edges of conical filling bars were found to be rounder. A possible reason for the better tensile strength of pulp refined with conical fillings is that the round edge helps large SW fiber flocs to enter the space between the bars, resulting in less heterogeneous or more efficient treatment of fibers. The recorded gap closure values supported the above interpretation. The gap between conical fillings was found to become wider when pulp consistency and thus fiber flocculation increased, whereas increased pulp consistency decreased the gap between plate fillings, which was further reflected as increased fiber cutting. The reduction in fiber length was proportional to the increase in gap closure, supporting the earlier theory that fibers are squeezed and crushed between the bars. More attention should be paid to the wear of filling materials when refining BSW. A filling material which wears so that the bar edges are rounded would seem to promote high tensile strength and high average fiber length.展开更多
The conditions of preparation and performance of a new structure of cationic organic polymeric micropaticles (CPMP) mainly composed of styrene and DADMAC were studied. And its application on retention and drainage on ...The conditions of preparation and performance of a new structure of cationic organic polymeric micropaticles (CPMP) mainly composed of styrene and DADMAC were studied. And its application on retention and drainage on bleached hardwood pulp was investigated and compared with that of APAM and CPAM. The results show that the retention and drainage of CPMP on pulp is in positive proportion to the rise of the potential of the solution, and the first-pass retention ratio of bleached hardwood pulp goes up with the increase of the CPMP content. The functions of CPMP and CPAM are affected less by the shear force and the pH value of the system compared to that of APAM, and effect on retention of CPMP3 is appropriate to that of CPAM, but superior to that of APAM.展开更多
文摘The purpose of this study was to compare plate and conical refiner fillings in refining of softwood and hardwood pulp fibers. Contrary to expectations, better tensile strength values were achieved when BSW was refined with conical fillings and the development of strength was found to be insensitive to variations in refining intensity. A bar microprofile was measured with the aid of a profilometer. The leading edges of conical filling bars were found to be rounder. A possible reason for the better tensile strength of pulp refined with conical fillings is that the round edge helps large SW fiber flocs to enter the space between the bars, resulting in less heterogeneous or more efficient treatment of fibers. The recorded gap closure values supported the above interpretation. The gap between conical fillings was found to become wider when pulp consistency and thus fiber flocculation increased, whereas increased pulp consistency decreased the gap between plate fillings, which was further reflected as increased fiber cutting. The reduction in fiber length was proportional to the increase in gap closure, supporting the earlier theory that fibers are squeezed and crushed between the bars. More attention should be paid to the wear of filling materials when refining BSW. A filling material which wears so that the bar edges are rounded would seem to promote high tensile strength and high average fiber length.
文摘The conditions of preparation and performance of a new structure of cationic organic polymeric micropaticles (CPMP) mainly composed of styrene and DADMAC were studied. And its application on retention and drainage on bleached hardwood pulp was investigated and compared with that of APAM and CPAM. The results show that the retention and drainage of CPMP on pulp is in positive proportion to the rise of the potential of the solution, and the first-pass retention ratio of bleached hardwood pulp goes up with the increase of the CPMP content. The functions of CPMP and CPAM are affected less by the shear force and the pH value of the system compared to that of APAM, and effect on retention of CPMP3 is appropriate to that of CPAM, but superior to that of APAM.
