Most fibers used today are synthetic, and are produced by melt spinning. They are primarily thermoplastic materials that are melt extruded through small holes and drawn down in air to filaments, thinner than human hair. The filaments are often mechanically spun (twisted) into yarn, which is then woven into fabric, tufted into carpet or stranded into rope.
HDPE can be spun (drawn down) to fine thickness — less than 20 microns. That fineness is difficult for LDPE to achieve because the molecular entanglements of LDPE's long chain branching retards draw down. However, The Dow Chemical Company (Dow) discovered that lower density (lower modulus) fibers could be spun with linear low density polyethylene. The family of ASPUN™ Fiber Grade Resins from Dow based on that technology has been in existence since 1983. Grades were developed for the major fiber processes (cardable staple, spun bond and melt blown) and for both single and bi-component (multilayer) filaments.