MONOFILAMENT HAVING HIGH TENACITY AND HIGH TENSILE UNIFORMITY AND METHOD AND APPARATUS FOR SPINNING AND DRAWING IT

摘要

PURPOSE: To obtain the subject filament having a standard deviation of tenacity and a tanacity of values in specific ranges, respectively by treating a quenched multifilament under specific conditions. CONSTITUTION: A multifilament sent from an air gap 13 and a quench bath 14 is drawn in at least about 3.0 draw ratio while being heated in a state provided with at least 10 wt.% water by a steamer 26. Further the filament is drawn while being heated by radiation by a heater 34. The total draw ratio is at least about 5.5. An oriented thermoplastic multifilament having a tenacity greater than about 7.5 g/d at a standard deviation in tenacity of less than 0.25 is obtained.