Filaments having trilobal or quadrilobal cross-sections

Multilobal fibers composed of a thermoplastic polymer, said fiber having a cross-section comprised of a central core having three or four T-shaped lobes projecting therefrom, each of said T-shaped lobes having a leg and a cap, the legs of each of said lobes intersecting at the center of said core such that the angle between the legs of adjacent T-shaped lobes is in the range of from about 80.degree. to about 130.degree., the legs of each of said T-shaped lobes having an average length, "W.sub.1 ", of from about 4.5 to about 25 .mu.m. from the center of sa1d central core, and an average width, "W.sub.t ", of from about 0.5 to about 20 .mu.m, the caps of each of said T-shaped lobes having an average length, "C.sub.l ", of from about 4.5 to about 50 .mu.m and each of the caps having an average width, C.sub.t ", of from about 0.5 to about 20 .mu.m, wherein the relative values of W.sub.1, W.sub.t, C.sub.1 and C.sub.t are selected such that:

• C.sub.1 (max)=2W.sub.1 -2C.sub.t and
• C.sub.1 (min)=2W.sub.t.