Process for making high-strength polylactic acid filament

Abstract

The present invention relates to a process for making high-strength polylactic acid elongated object comprising the steps of making a solution of polylactic acid in a solvent at a concentration of 5 to 50 mass %; spinning the solution through a spinplate comprising at least 1 spinhole to form a fluid elongated object; cooling the fluid elongated object with a cooling medium to form a solvent-containing gel elongated object; removing at least partly the solvent from the gel elongated object to form a solid elongated object; and drawing the elongated object while applying a draw ratio of at least 2, to form a high strength PLA elongated object, characterized in that the cooling medium has a temperature Tq of less than 0° C. The present invention also relates to gel-spun elongated objects comprising PLA with an IV in the range of 4-40 dl/g, and having a tenacity in N/tex such that Ten≥0.146*IV, as well as gel-spun elongated object having a tenacity and a filament titer in tex (t) such that Ten≥1.40*t −0.3. The invention also relates to articles containing said gel-spun elongated objects.

Dependencies are inferred from the claim text.