Novel CO₂ laser drawing of thermotropic liquid crystal polymer and poly(ethylene 2,6-naphthalate) blend fibers

Thermotropic liquid crystal polymer (TLCP)/poly(ethylene 2,6-naphthalate) (PEN) were prepared by a melt blending, and were melt spun by a spin-draw process. In this study, we suggest novel drawing technology using the CO ₂ laser that can directly and uniformly heat up fiber inside to prevent the formation of ununiform structures in conventional heat drawing process. The properties of the heat/laser drawn TLCP/PEN blend fibers were superior to those of any other handled fibers, and were rather more excellent than those of TLCP/PEN blend fibers annealed at 135°C for 10 min. It was confirmed that the CO₂ laser drawing made it possible to achieve the optimal drawing effect by draw ratio. The combined heating and CO₂ laser-drawing method has a great potential for industrial applications as a novel fiber-drawing process, and it can also be applied continuously to conventional spin-draw system.