Abstract: The use of primary and secondary amines and certain other compounds in ferricyanide assisted oxygen delignifying bleaching of lignocellulosic pulps permits more rapid removal of a desired amount of lignin from the pulp and, hence, the retention of higher pulp viscosity.

Abstract: High crimp, high strength, hollow rayon fibers or filaments which maintain their hollowness after being immersed in water and subsequently dried, and have a crimped configuration such that there is in excess of about 20 crimps per inch, preferably between about 25-30 crimps per inch, are provided by an in-line process whereby a viscose solution containing a blowing agent is extruded into an aqueous acid coagulating bath. The conditions of the process result in hollow filaments that are substantially irreversible since they remain hollow and do not collapse even after repeated washing and drying cycles. The hollow filaments possess high crimp, such as about 25-30 crimps per inch, which will permit ease in carding and blending with other fibers. The high crimp hollow fibers also possess high strength nearly equivalent to that of high wet modulus rayon fibers.

Abstract: High crimp, high strength, hollow rayon fibers or filaments which maintain their hollowness after being immersed in water and subsequently dried, and have a crimped configuration such that there is in excess of about 20 crimps per inch, preferably between about 25-30 crimps per inch, are provided by an in-line process whereby a viscose solution containing a blowing agent is extruded into an aqueous acid coagulating bath. The conditions of the process result in hollow filaments that are substantially irreversible since they remain hollow and do not collapse even after repeated washing and drying cycles. The hollow filaments possess high crimp, such as about 25-30 crimps per inch, which will permit ease in carding and blending with other fibers. The high crimp hollow fibers also possess high strength nearly equivalent to that of high wet modulus rayon fibers.

Abstract: A method of producing textile-like non-woven essentially binderless webs from fiber furnishes at least about 70% of which comprise man made non-fibrillatable low denier fibers having no large area flat surfaces and which are at least about 1/4 inch in length with a length to diameter ratio of between about 400:1 and 700:1. The method includes a wet laying system in which sufficient wetting agent is added to the water used in dispersing the fibers to wet the fibers completely and reduce the surface tension of the water to between about 30-35 dynes. It also includes agitating the dispersion vigorously to create tumbling water surface conditions in which up to, but less than about 4% by volumeof air is entrained in the water in the form of tiny air bubbles to create a water/air emulsion in which the fibers are dispersed without generating any substantial amount of surface foam.