Method of and apparatus for the production of pads or mats of fibers from thermoplastic materials

Abstract

Abstract The invention relates to the production of homogeneous and structurally resistant sheets or mats of thermoplastic fibers, such as glass fibers, issuing from a rotary centrifuge above a traveling conveyor. The molten filaments, discharged in radial directions is substantially horizontal planes, are transformed into fibrous form by a downwardly directed annular attenuating gaseous blast, and the resulting annular curtain of fibers is guided through a shaping assembly comprising a tuyere having a circular inlet and an elongated rectangular outlet with substantially elliptical intermediate sections of increasing flatness therebetween in the direction of travel of the curtain of fibers. The flattened curtain of fibers then passes through a shaping member formed essentially of a pair of large trapezoidally-shaped plane surfaces of predetermined spacings therebetween to obtain critical cross-sectional areas at its inlet and outlet as well as at intermediate portions thereof, with convergent portions between said surfaces, as well as provisions for the introduction of air into the interior thereof, which aid in the conveyance of the fibers to the outlet of said shaping member in proximity to the conveyor, whereon they are deposited smoothly across substantially the entire width thereof without the formation of lumps or nodules.

Inventors

• 👤 J Kirchheim

Bibliographic Details