Flow and Die-Swell Behavior in Extrusion of PLLA Melts

摘要

The rheological properties of two kinds of poly (L-lactic acid) melts (Al-1001 and 403 2D) have been investigated using a melt flow indexer within the temperature range from 170 to 190°C and load varying from 2.16 to 12.5 kg. It was found that the melt volume flow rate (MVR) and extrudate swell ratios (B) increased non-linearly with increasing load when the temperature was constant; the MVR increased while the B decreased with a rise in temperature for both the AI-1001 and 4032D melts; the relationship between the MVR and temperature obeyed expression like as the Arrhenius equation when the load was fixed. Under the same test conditions, the values of the MVR and B of the AI-1001 melt were higher than those of the 4032D melt, and the sensitivity of the MVR and B to the load for the former is higher than those for the latter.