Amulti filament yarn is composed of a bundle of very thin, infinitely long threads. The threads are generally referred to as filaments.
These yarns are generally spun on vertical machines with filaments extruded out of the spinnerets and air-cooled before getting wound onto spools.
After this, the thin filaments (maximum about 280) are stretched to the required draw ratio in a more or less continuous drawing process. Multifilament yarns containa multitude of fine, continuous filaments (often 5 to 100 individual filaments)usually with some twist in the yarn to facilitate handling.
Sizes range from 600 to 5040 denier up to a few hundred denier.
Because of the very small diameters of the filaments in multifilament yarns, their bending stiffness is much lower than that of monofilaments. This leads to muchmore flexible end-products. Furthermore, using multifilament yarns, denserfabrics can be obtained yielding smaller pores.