Melt-drawing, cooling, attenuating, and heat treating under tension, of filament

Abstract From the Canadian patent

A fiber which will perform in pile fabrics such as carpets is made from a low cost polymer for example, copolymers of ethylene and vinyl acetate. This fiber is characterized by an elastic modulus of from 5,000 to 60,000 psi, an area moment of inertia of from 400 x 10-14 to 7,000 x 10-14 in4, and a stiffness parameter (as defined herein) of from 1 x 10-5 to 1 x 10-8 lb - in2. For good coverage, the pile fabric made from such fiber will have a minimum of 4,000 fibers per square inch of backing and a minimum pile height of 1/8 inch, The invention also provides for a method of making a fiber of the above characteristics which includes sequential steps of extruding drawing, rapid cooling, …