Abstract: A continuous process for the recycling of aramid fiber comprising the following steps: combining aramid fibrous material including non-continuous aramid fibers with sulfuric acid to obtain a spin dope comprising aramid, and processing the spin dope including aramid into a continuous aramid fiber. The invention also pertains to a continuous aramid fiber, preferably obtainable by said process, and to a multifilament yarn including the continuous aramid fiber.

Abstract: A process for manufacturing a fiber including meta-aramid having a breaking tenacity of at least 300 mN/tex including the steps of preparing a spin dope including meta-aramid and sulfuric acid having a concentration of at least 80 wt % and passing the spin dope through a spinneret into a coagulation bath, wherein the spin dope has a meta-aramid concentration of at least 10 wt %. The invention also pertains to a meta-aramid fiber, a multifilament yarn, a textile sheet and protective clothing.

Abstract: A process for manufacturing a fiber including polyetherketoneketone including the steps of: mixing polyetherketoneketone and sulfuric acid having a concentration of at least 90 wt % to obtain a spin dope and passing the spin dope through a spinneret into a coagulation bath, wherein the polyetherketoneketone is dissolved in the sulfuric acid to a concentration of 12 to 22 wt %. Also disclosed are fibers obtainable by the process and polyetherketoneketone fibers having a sulfur content of 0.001 to 5 wt %, based on the weight of the fiber, in particular such fibers having low or high crystallinity, as well as, hybrid yarns and composite materials.

Abstract: A process for manufacturing shaped articles containing carbon nanotubes including the steps of supplying carbon nanotubes in an acidic liquid containing at least one acid, the at least one acid having a Hammett acidity function less than that of 100% sulfuric acid, the at least one acid having a Hammett acidity function equal or more than that of 90% sulfuric acid, and shaping the acidic liquid comprising carbon nanotubes into a shaped article.

Abstract: A process for manufacturing a fiber including polyetherketoneketone including the steps of: mixing polyetherketoneketone and sulfuric acid having a concentration of at least 90 wt % to obtain a spin dope and passing the spin dope through a spinneret into a coagulation bath, wherein the polyetherketoneketone is dissolved in the sulfuric acid to a concentration of 12 to 22 wt %. Also disclosed are fibers obtainable by the process and polyetherketoneketone fibers having a sulfur content of 0.001 to 5 wt %, based on the weight of the fiber, in particular such fibers having low or high crystallinity, as well as, hybrid yarns and composite materials.

Abstract: The invention relates to a method for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising DAPBI, an aromatic para-diamine, and an aromatic para-diacid, wherein the yarn is heated in at least two process steps, characterized in that in a first step the yarn is heated at a temperature of 200 to 360° C. at a tension of at least 0.2 cN/dtex, followed by a second step wherein the yarn is heated at a temperature of 370 to 500° C. at a tension of less than 1 cN/dtex. The invention further pertains to a multifilament aramid yarn spun from a sulfuric acid spin dope and having a tenacity of at least 2500 mN/tex.

Abstract: The invention relates to a method for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising DAPBI, an aromatic para-diamine, and an aromatic para-diacid, wherein the yarn is heated in at least two process steps, characterized in that in a first step the yarn is heated at a temperature of 200 to 360° C. at a tension of at least 0.2 cN/dtex, followed by a second step wherein the yarn is heated at a temperature of 370 to 500° C. at a tension of less than 1 cN/dtex. The invention further pertains to a multifilament aramid yarn spun from a sulfuric acid spin dope and having a tenacity of at least 2500 mN/tex.

Abstract: The invention relates to a method for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising DAPBI, an aromatic para-diamine, and an aromatic para-diacid, wherein the yarn is heated in at least two process steps, characterized in that in a first step the yarn is heated at a temperature of 200 to 360° C. at a tension of at least 0.2 cN/dtex, followed by a second step wherein the yarn is heated at a temperature of 370 to 500° C. at a tension of less than 1 cN/dtex. The invention further pertains to a multifilament aramid yarn spun from a sulfuric acid spin dope and having a tenacity of at least 2500 mN/tex.

Abstract: Disclosed is a composite material comprising PPTA (poly-p-phenyleneterephthalamide) and nanotubes having an aspect ratio of at least 100 and a cross-sectional diameter of 5 nm or less, the composite material containing up to 12 wt. % of nanotubes, obtainable by adding the nanotubes to sulfuric acid, decreasing the temperature to solidify the mixture, adding PPTA to the solid mixture, heating to above the solidifying point and mixing the mixture, and spinning, casting, or molding the mixture to the composite material.

Abstract: The invention relates to a method for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising DAPBI, an aromatic para-diamine, and an aromatic para-diacid, wherein the yarn is heated in at least two process steps, characterized in that in a first step the yarn is heated at a temperature of 200 to 360° C. at a tension of at least 0.2 cN/dtex, followed by a second step wherein the yarn is heated at a temperature of 370 to 500° C. at a tension of less than 1 cN/dtex. The invention further pertains to a multifilament aramid yarn spun from a sulfuric acid spin dope and having a tenacity of at least 2500 mN/tex.

Abstract: Disclosed is a composite material comprising PPTA (poly-p-phenyleneterephthalamide) and nanotubes having an aspect ratio of at least 100 and a cross-sectional diameter of 5 nm or less, the composite material containing up to 12 wt. % of nanotubes, obtainable by adding the nanotubes to sulfuric acid, decreasing the temperature to solidify the mixture, adding PPTA to the solid mixture, heating to above the solidifying point and mixing the mixture, and spinning, casting, or molding the mixture to the composite material.

Abstract: The invention pertains to a composite material comprising PPTA (poly-p-phenyleneterephthalamide) and nanotubes having an aspect ratio of at least 100 and a cross-sectional diameter of 5 nm or less, the composite material containing up to 12 wt. % of nanotubes, obtainable by adding the nanotubes to sulfuric acid, decreasing the temperature to solidify the mixture, adding PPTA to the solid mixture, heating to above the solidifying point and mixing the mixture, and spinning, casting, or molding the mixture to the composite material. The process comprises the steps: a) adding nanotubes having an aspect ratio of at least 100 and a cross-sectional diameter of 5 nm or less to sulfuric acid at a temperature above the solidifying point of the sulfuric acid; b) decreasing the temperature to below the solidifying point of the sulfuric acid and mixing for a sufficient time to solidify the mixture; c) adding PPTA to the solid mixture; and d) heating to above the solidifying point and mixing the mixture.

Abstract: The invention pertains to a composite material comprising PPTA (poly-p-phenyleneterephthalamide) and nanotubes having an aspect ratio of at least 100 and a cross-sectional diameter of 5 nm or less, the composite material containing up to 12 wt. % of nanotubes, obtainable by adding the nanotubes to sulfuric acid, decreasing the temperature to solidify the mixture, adding PPTA to the solid mixture, heating to above the solidifying point and mixing the mixture, and spinning, casting, or molding the mixture to the composite material. The process comprises the steps: a) adding nanotubes having an aspect ratio of at least 100 and a cross-sectional diameter of 5 nm or less to sulfuric acid at a temperature above the solidifying point of the sulfuric acid; b) decreasing the temperature to below the solidifying point of the sulfuric acid and mixing for a sufficient time to solidify the mixture; c) adding PPTA to the solid mixture; and d) heating to above the solidifying point and mixing the mixture.

Abstract: A process for preparing fibers from an optically anisotropic solution containing either one of cellulose or cellulose derivatives by extruding the solution through a non-corroding spinneret and coagulating the resulting extrudates in a coagulant, the coagulant being a liquid which contains mostly water and to which cations have been added.

Abstract: The present invention is directed to a multifilament yarn having regenerated cellulose filaments.

Abstract: Cellulose fibres and filaments are prepared from a spinnable, cellulose-containing solution containing 94-100 wt. % cellulose, water, and phosphoric acid and/or anhydrides of phosphoric acid. The resulting cellulose fibres and filaments have an elongation break point greater than 7%. The cellulose-containing solution used to prepare the fibres and filaments may be either isotropic or anisotropic. The cellulose-containing solution is coagulated in a liquid containing water and cations, and the cations are preferably monovalent. Fibres and filaments prepared in this manner are especially suitable for use in textiles.

Abstract: A process for preparing a material having a high water and salt solutions absorbency, the material containing mainly cellulose that is dissolved in a solvent containing phosphoric acid, a solution is obtained that contains 94-100 wt. % of the following constituents:cellulose,phosphoric acid and/or its anhydrides, andwater,the solution is then coagulated and washed in a liquid containing less than 50 wt. % of water. This process can be used to obtain cellulose products, such as fibers or pulp, which have a high water and (isotonic) salt solutions absorbency.

Abstract: Cellulose extrudates can be made from an optically anisotropic solution containing 94-100 wt % of: cellulose; phosphoric acid and/or its anhydrides; and water by extruding the solution, coagulating the formed extrudates, and then aftertreating those extrudates so that they have a degree of acidity which at least equals 7. Fibers obtained by such a processs possess particularly good thermal stability and are suitable for use as a reinforcing material.

Abstract: The disclosure describes a process for the preparation of regenerated cellulose filaments from an anisotropic solution including cellulose formate, phosphoric acid, and formic acid in which the formed cellulose formate filaments are dried to a moisture content of not more than 15% prior to regeneration and after regeneration the filaments are washed and dried under low tension. In this manner cellulose multifilament yarns of high breaking load and high elongation at break can be obtained, which in addition have a very regular linear density.

Abstract: An optically anisotropic solution containing cellulose and inorganic acids of phosphorus contains 94-100 wt % of the following constituents: cellulose; phosphoric acid and/or its anhydrides; and water; and 0-6 wt % of other constituents. This solution can be prepared in an apparatus in which intensive mixing is made possible by the shearing forces generated by mixers and kneaders in the apparatus. The solution can be used in making pulp, hollow fibres, staple fibre, membranes, nonwovens, or films.