Filamento de poliéster semicristalino obtido por fiação em meio em fusão e estiramento e processo de fabricação de um filamento de poliéster semicristalino sintético obtido por extrusão em meio em fusão de pelo menos um filamento

摘要

PCT No. PCT/FR97/01193 Sec. 371 Date May 25, 1999 Sec. 102(e) Date May 25, 1999 PCT Filed Jul. 3, 1997 PCT Pub. No. WO98/01609 PCT Pub. Date Jan. 15, 1998The invention concerns polyester filaments and method for manufacturing same. More particularly it concerns a filament made of glycol ethylene polyterephtalate or polynaphtalate having high mechanical properties, and a method for stretching polyester filaments. It is obtained by a stretching process comprising two steps including a first step in which a low stretching ratio is applied, to cause minimal crystallization of the polymer and, a second step with a high stretching ratio. The global stretching ratio can reach values higher than 12. The filament has in particular an expanded elastic range that enables the improvement of its useful properties, for instance for manufacturing screen printing grids.