Fiber Drawing
A process for drawing a continuous fiber or monofilament from a supply of viscous liquid through a calibrated orifice has been developed. The steps included forming a laminar flow in a moving screen of fluid, and introducing the fiber into that moving stream at a predetermined distance from the calibrated orifice such that the fiber is fully solidified and formed before a frictionally generated pulling force is applied to the fiber. The fiber is, then pulled or drawn into a continuous fiber or monofilament without any physical or mechanical handling. A monofilament or continuous fiber drawn in such a process has a diameter which, for all practical purposes, is constant. However, the diameter can be changesby makingadjusting the operating conditions. This process is suitable for the very high drawing speeds required for the economical production of "Beta" or other types of textile fibers. This process is adaptable for drawing monofilament or continuous fibers such as nylon, rayon, viscose and so on; as well as being especially suited for drawing continuous fibers of glass. The rate at which the monofilament or continuous fiber is drawn can be varied (a) by changing the velocity of the moving stream of fluid; (b) by altering the diameter of the calibrated orifice (or as it is known in the glass-making industry, the "bushing" orifice) from which the fiber is initially drawn; (c) by varying the viscosity of the liquid at the source, from which the fiber is made; or (d) by various combinations thereof. Preferably, the fluid which is used in the present process is a gas or vapour, commonly air, although steam or some other vapor or gas could also be used, so long as the vapour or gas is chemically inert relative to the material of which the continuous fiber is made. (Schmidt, US Patent 3,945,815; 3/23/1976)
Recent Journal Articles
2/4/2011
Ultradrawing properties of ultrahigh- molecular-weight polyethylene/carbon nanotube fibers prepared at various formation temperatures
(59–68)Polymer International 60 #1 (2011)
Yeh et al from Taiwan and China studied the influence of formation temperature on the ultradrawing properties of ultrahigh-molecular-weight polyethylene/carbon nanotube (UHMWPE/CNT) fiber specimens. The achievable draw ratio (Dra) values of UHMWPE/CNT as-prepared fibers reach a maximum when they are prepared with the optimum CNT content and formation temperature. The Dra value of UHMWPE/CNT as-prepared fibers produced using the optimum CNT content and formation temperature is about 33% higher than that of UHMWPE as-prepared fibers produced using the optimum concentration and formation temperature. The percentage crystallinity (Wc) and melting temperature (Tm) of UHMWPE/CNT as-prepared fiber specimens increase significantly as the formation temperature increases. In contrast, Wc increases but Tm decreases significantly as the CNT content increases. (RDC 2/3/2011)