| 摘要 |
<p>Process making use of semi-crystalline thermoplastic polymer comprises extruding thermoplastic and cooling it to temperature T1, where T1 > crystallisation temperature, Tc and < Tf + 5 degrees C, Tf = melting point of thermoplastic; stretching extrudate; allowing extrudate to relax at temperature T3, where Tc < T3 < Tf, for time = average relaxation time of thermoplastic; and soaking extrudate at temperature T4, where T4 < Tc. Also claimed is film made by said process.</p> |
