| 초록 |
Over the years, due to the importance of polyethylene in the plastic industry, the studies on extrusioninstability have received considerable attention. It is well known that the melt fracture of various shapesand related processing instabilities continue to limit processing rate in many commercially importantpolymer processing [1, 2]. Therefore, over the critical processing rate occurring melt fracture or flowinstability, the melt fracture was fallen off in quality and mechanical properties of final product. In thisstudy, to increase processing rate and improve the quality of final product, a commercial LLDPE wasmodified by adding small amount of Boron Nitride(BN) during extrusion. When the neat LLDPE wasmodified by adding various BN contents, we investigated about the effects of BN on the rheologicalproperties, extrudate swell ratio, processability of LLDPE. Also, processability of capillary flow wasinvestigated as functions of temperature, applied shear rate and the length to diameter (L/D) ratio for theneat LLDPE. Additionally, The relationship between the apparent characteristic relaxation time and thecritical shear rate for the onset of melt fracture and slip was discussed. |
