| 摘要 |
PURPOSE:To produce the subject fiber high strength, high modulus and excellent dimensional stability under heat and resistant to thermal deterioration in rubber in high efficiency by melt-spinning a polyester having a specific viscosity, drawing the obtained intermediate oriented fiber in a plasma and heat-treating in relaxed state to obtain a highly oriented fiber. CONSTITUTION:Direct spinning and drawing of a polyester fiber can be carried out by melt-spinning polyester chips having an intrinsic viscosity [eta] of >=0.8, cooling and solidifying the spun fiber, winding the solidified fiber around a take-up roller to obtain an intermediate oriented fiber having a birefringence of 30X10<-3> to 100X10<-3> and a density of 1.335-1.380g/cm<3>, successively introducing the intermediate oriented fiber into a drawing zone, drawing the fiber in the first state of the drawing zone at a draw ratio of 1.4-3.5 under the application of a tension of 2.0-5.0g/d in a plasma atmosphere having reduced pressure, transferring the drawn fiber to a relaxed heat-treatment zone and subjecting to the heat-treatment under relaxation of 0-10% to form a highly oriented polyester fiber having a birefringence of >=180X10<-3>. |
