Abstract: A catalyst suitable for use in the preparation of fiber-forming polyesters and the method of making the same, wherein a tetraalkyl ammonium hydroxide is reacted with germanium dioxide, the reaction product being useful as a catalyst in the formation of fiber-forming polyesters.

Abstract: The method for production of polyester staple yarn having sufficiently low elongation and shrinkage and high tenacity and modulus for use in thread, sewing thread, cord, twine and in cordage products, wherein a tow of conventionally spun polyester filaments is drawn in an aqueous draw zone and then dried at 130.degree. to 140.degree. C, stretched 1.1 to 1.2X and then heat set at 170.degree. to 200.degree. C. The tow is then crimped, cut to staple and spun into yarn. The dwell time between the drying step and the step of stretching 1.1 to 1.2 times is sufficiently low that this stretch can be accomplished before the fibers in the tow can crystallize to the point that this stretch cannot be achieved. Dwell time in the heat set zone must be at least 10 seconds.

Abstract: In a strand forming machine wherein a polymeric strand in molten form is fed downward into and through an upright tube positioned below the surface of a liquid quenching medium in a container having a bottom and side walls, the improvement comprising a hollow element mounted in the container and surrounding the tube, the hollow element extending above the side wall of the container and having a channel extending outwardly over the wall of the container in such a manner that in the event the strand fails to pass through the tube the excess molten strand will accumulate in and flow outward through the channel to a location outside the container.

Abstract: A semi-continuous polyester esterification process employing continuous feeding and discontinuous withdrawal is combined with a plurality of batch polycondensation processes to produce outstanding polyester polymer with improved flexibility (of process and product) and efficiency.