American Cyanamid Company

Robert P Kreahling

Donald J Casey

David Z Goldenberg

Ronald E Pfeiffer

George K Klausner

Vinod T Sinha

A process for preparing an acrylonitrile polymer fiber is disclosed wherein melt-spun acrylonitrile polymer filaments are maintained in a stretchable state as spun, stretched in at least two stages while maintained in such stretchable stage, the first stage being at a stretch ratio of up to about 5 and the subsequent stretch being at a stretch ratio greater than that of said first to provide a total stretch ratio of at least about 25.

Melt-spinning a plurality of acrylonitrile polymer fibers

Polyester filaments of improved drawability and improved adhesion to rubber are prepared by applying to polyester filaments coated with aromatic isocyanate containing at least two isocyanate groups per molecule 0.02 to 0.4% on weight of fiber of a hydroxy-containing finish less than 1 hour prior to drawing such filaments to 4 to 7 times their undrawn length.

Drawing isocyanate-treated polyester filaments

Polyester filaments treated with aromatic isocyanate to provide improved adhesion to rubber also have improved fatigue resistance and improved drawability provided the aromatic isocyanate used is a mixture of 50 to 90% di-functional aromatic isocyanates and the remainder higher than di-functional aromatic isocyanates.

Treatment of polyester filaments with aromatic isocyanate mixture

There is disclosed an improvement in the continuous melt extrusion of a refractory polymer and its melt assistant by which a porous plug of the composition being extruded is formed between the compressing zone and the melting zone of the extruder so as to prevent loss of vaporized melt assistant by backward escape through the feed inlet.

Growing community of inventors

Fairfield, CT, United States of America

Robert P Kreahling