Abstract: Polyethylene yarns having tenacities of at least 12 grams per denier are produced at commercially feasible spinning speeds by a process in which a high density polyethylene having a M.sub.n of at least 20,000 and a M.sub.w of less than 125,000 is extruded through a high temperature spinneret (220.degree.-335.degree. C.) to form yarns which are hot-drawn at a temperature between about 115.degree. and 132.degree. C. The yarns produced by this process are particularly useful as industrial cordage.

Abstract: Crimped side-by-side bicomponent filaments consisting of a polyamide and CaF.sub.2 are produced in which the CaF.sub.2 is dispersed in only one of the components.

Abstract: A fabric suitable for use in making sandbags and the method of making the same wherein the fabric is woven from a yarn of twisted staple acrylic fibers having a fiber length of about 7 to 20 cm and a denier per filament of about 5 to 15, preferably 10 to 15, the yarn having a total denier of about 200 to 2650. The yarn is wrapped with a continuous filament yarn of a type which is degraded by ultraviolet light, with the wrapping being done in such a manner that fuzziness of the yarn is reduced to the point where the yarn can be woven into fabric without the use of size and at a weaving efficiency of at least about 70%.

Abstract: An acrylic fiber having improved basic dyeability and hot/wet properties, the fiber being made up of a blend of (a) at least 60 weight percent of a polymer of at least 35 weight percent of acrylonitrile copolymerized with up to 65 weight percent of at least one other mono-olefinic monomer and a minor amount of a sulfonated vinyl monomer with (b) 0.5 to 40 weight percent of the polyterephthalamide of a mixture of 2,2,4 and 2,4,4 trimethyl hexamethylene diamine, the fiber being made up of a two-phase heterogeneous suspension of the polyterephthalamide in a continuous phase of the acrylic polymer. Without the sulfonated vinyl monomer the fiber will have superior hot/wet properties but will show no improvement in dyeability, the dyeability of the fiber being enhanced only when the sulfonated vinyl monomer is present as a part of the acrylic polymer chain.

Abstract: Fiber-forming 6T/6I terpolyamides having melting points below 320.degree. C., glass transition temperatures above 115.degree. C. and good thermal stablities are provided. The terpolyamides may be prepared by melt polymerization and melt spun into useful fibers.

Abstract: A spin-texture process for producing crimped synthetic filaments is described in which freshly extruded filaments are passed over a 20.degree. C.-180.degree. C. roll before they are completely solidified and fully drawn as they leave the roll. In the case of polyamide filaments, spontaneous crimp as well as latent crimp is observed.

Abstract: A melt spinning process for producing nominal 20 denier per filament polyamide yarn having a latent bulk of at least 18% is provided. The process employs polyhexamethylene adipamide modified to contain from 1 to 10 mole % of recurring units of the formula ##STR1## whereby wind-up speeds ranging from 1830 to 4570 meters per minute and higher are attainable. The resulting yarn has a usable bulk, when developed, for carpet yarn applications without further texturing of the yarn.

Abstract: Fiber-forming polymers are prepared from a mixture of the hexamethylene diamine salts of terephthalic acid, isophthalic acid, and a small amount of at least one aliphatic dibasic acid (e.g. adipic acid) having from 5 to 12 carbon atoms. The polymers can be prepared in a batch autoclave and extruded therefrom without cleaning the autoclave between successive runs.

Abstract: Polyethylene yarns having tenacities of at least 12 grams per denier are produced at commercially feasible spinning speeds by a process in which a high density polyethylene having a M.sub.n of at least 20,000 and a M.sub.w of less than 125,000 is extruded through a high temperature spinneret (220.degree.-335.degree. C.) to form yarns which are hot-drawn at a temperature between about 115.degree. and 132.degree. C. The yarns produced by this process are particularly useful as industrial cordage.

Abstract: The productivity of the conventional melt spinning process for producing undrawn polyhexamethylene adipamide carpet and tire yarns is increased by utilizing a heat feed roll (e.g. 80.degree. C.) rather than an unheated feed roll and by eliminating the conventional steam conditioning of the yarn and the convergence guide(s) associated therewith.

Abstract: A process for improving tensile properties of aramid fibers and structurally related fibers is described. The process involves soaking the fibers in a liquid tertiary amine maintained at a temperature of at least 80.degree. C.

Abstract: Polyamide fibers containing one or more of a certain class of poly(copper phosphinates) have improved resistance to color fading when dyed with disperse dyes and exposed to ozone than do corresponding fibers from which the phosphinate has been omitted.

Abstract: High strength fibers of arylene oxadiazole/arylene N-alkylhydrazide copolymers are prepared by a unique solution spinning process, whereby an arylene oxadiazole/arylene N-alkyloxadiazolium hydrosulfate copolymer in sulfuric acid or oleum is extruded into an aqueous coagulation medium in which concurrently a fiber is formed and the latter-mentioned copolymer undergoes a chemical transformation to provide the first-mentioned copolymer.

Abstract: A spin-texture process for producing polyamide yarns is described in which a freshly extruded yarn is passed between two pairs of rotating rolls and then collected. The second pair of rolls (draw rolls) is driven at a peripheral speed greater than that of the first pair of rolls (feed roll and its associated separator roll). The feed roll is maintained and a given temperature which is correlated with other processing conditions to impart a desired level of latent crimp to the yarn. Yarns prepared by the process have a potential bulk of between 10% and 50% and are particularly useful as carpet yarns.

Abstract: A process for incorporating CaF.sub.2 into polyamides is described. The process involves reacting a calcium salt with a fluoride salt in molten polyamide.

Abstract: Anisotropic dopes composed of an aromatic polyamide in oleum are produced by polymerizing an aromatic diamine such as p-phenylenediamine sulfate and an aromatic diacid such as terephthalic acid in sulfur trioxide.

Abstract: Yarns of phenylene oxadiazole/N-alkylhydrazide copolymers are made by a wet spinning process involving the steps of extruding, coagulating, washing, drying, hot-drawing and collecting. These yarns when formed into cord lose considerable tenacity, that is, cords plied from these yarns have considerably less tenacity than the individual yarns making up the cords. It has been found that this loss in tenacity in forming cords can be significantly reduced by applying a certain zirconium-containing finish to the yarn during its preparation. The finish is applied after the yarn is washed and while it is still wet.

Abstract: An electrically conductive side-by-side biconstituent melt spun fiber is provided having a conductive constituent and a nonconductive constituent. Both constituents comprise a relatively nonconductive polymer. The conductive constituent additionally contains an electrically-conductive material, such as carbon black and wraps around the nonconductive constituent.

Abstract: A process for utilizing scrap aromatic oxadiazole/N-alkyhydrazide copolymer by dissolving the scrap copolymer in oleum thereby effecting degradation thereof and heating the resulting solution at a temperature between about 100.degree. C. and 160.degree. C. to form a polymer solution. Articles such as fibers can be shaped from this solution by combining the solution with an aqueous medium such as water.

Abstract: Fibers of arylene oxadiazole/arylene N-alkylhydrazide copolymer and of high tensile strength are prepared by a unique solution spinning process, whereby an arylene oxadiazole/arylene N-alkyloxadiazolium hydrosulfate copolymer in sulfuric acid or oleum is extruded into an aqueous coagulation medium in which concurrently a fiber is formed and the latter-mentioned copolymer undergoes a chemical transformation to provide the first-mentioned copolymer.