| 摘要 |
PURPOSE:To obtain the titled fiber having high tenacity and modulus, by carrying out the multi-stage drawing of a yarn under a specific condition placing a heater between rollers. CONSTITUTION:The spinning dope obtained from a 3-15wt% solution of a polyethylene having a weight-average molecular weight of >=800,000 is subjected to the multi-stage drawing using a heater attached between rollers. The first-stage drawing is carried out at a feed speed of 0.2-10m/min, a draw ratio of >=10 (70-90% of the maximum draw ratio) and a draw rate (DR1) of 1-15/min. The elontations of the second stage and thereafter are carried out at a draw rate (DRn) of 0.1-3/min. The total draw ratio is adjusted to >=20. The draw rate DRn of the n-th drawing is calculated by the formula [HDn is draw ratio in the n-th drawing; Vn is feed speed (m/min) in the n-th drawing; Ln is the length of the heater (m) in the n-th drawing].
|
