Le. Bailey et al., ELONGATIONAL FLOW PROPERTIES OF LOW-DENSITY POLYETHYLENE AND LINEAR LOW-DENSITY POLYETHYLENE FROM NONISOTHERMAL MELT-SPINNING EXPERIMENTS, Polymer engineering and science, 34(19), 1994, pp. 1485-1491
Low-density polyethylene (LDPE) and also Linear low-density polyethyle
ne (LLDPE) resins can be characterized by the degree of strain hardeni
ng and down-gaging during elongation. A new method for the determinati
on of the apparent elongational flow characteristics is presented. In
a small scale apparatus, a molten monofilament is stretched under noni
sothermal conditions similar to those found in tubular film extrusion.
Measurement of resistance to elongational flow and apparent elongatio
nal strain rates permit the comparison of the processability of differ
ent resins under specified conditions. The effect of melt temperature
and extension ratio are examined. The importance of the molecular stru
cture of both LDPE and LLDPE resins on these properties is also outlin
ed.