Polytrimethylene terephthalate fiber and method for producing same

Abstract

The polytrimethylene terephthalate fiber satisfies the requirements that a peak value of the thermal stress of the fiber be present in the temperature range of from 40 to 100° C., the peak value be 0.1 to 0.8 cN/dtex, and the fiber have an elongation at break of 60 to 200%. The method for producing a fiber includes melting and solidifying polytrimethylene terephthalate, and then winding up the solidified polytrimethylene terephthalate at a winding speed of 1,000 m/minute or more, and heating the resultant polytrimethylene terephthalate using a heated roller at a temperature which is ±20° C. of the glass transition point of polytrimethylene terephthalate, and drawing the heated polytrimethylene terephthalate at a draw ratio of 1.0 to 2.0 times, and further winding the drawn polytrimethylene terephthalate round a heated roller at 50 to 150° C. and then winding up the resultant polytrimethylene terephthalate at a rate of 2,000 to 4,800 m/minute.

Dependencies are inferred from the claim text.