Abstract: A textile substrate made from reinforcing fibers for the production of composite-material preforms, Including an unidirectional composite consisting of at least one flat layer of multifilament reinforcing yarns arranged alongside and parallel to one another and joined by transverse threads, whereby a nonwoven of thermoplastic polymer material is arranged on the at least one flat layer of multifilament reinforcing yarns and is adhesively bonded to the flat layer of multifilament reinforcing yarns. The textile substrate wherein the transverse threads have a core/sheath structure with a first component forming the sheath and a second component forming the core, wherein the first component has a lower melting point than the second component, the first component is a fusible thermoplastic polymer material and the multifilament reinforcing yarns arranged alongside one another are joined together via the first component of the transverse threads by meltbonding.

Abstract: Method for producing a textile unidirectional fabric, wherein at least one planar layer of multi-filament reinforcement threads arranged parallel to each other are woven with each other over transverse threads, wherein transverse threads having core-sheath structure and titer of 10 to 40 tex are used as transverse threads, wherein transverse threads have a first component, which structures sheath, and second component, which structures core, wherein first component has lower melting temperature than second component, first component is meltable thermoplastic polymer material and, via first component of transverse threads, adjacently arranged multi-filament reinforcement threads are connected to each other by hot melting, wherein alleys are formed in unidirectional fabric by interweaving multi-filament reinforcement threads together with transverse threads, by means of which a permeability of 10 to 600 l/dm2/min can be established.

Abstract: A textile substrate made from reinforcing fibers for the production of composite-material preforms, Including an unidirectional composite consisting of at least one flat layer of multifilament reinforcing yarns arranged alongside and parallel to one another and joined by transverse threads, whereby a nonwoven of thermoplastic polymer material is arranged on the at least one flat layer of multifilament reinforcing yarns and is adhesively bonded to the flat layer of multifilament reinforcing yarns. The textile substrate wherein the transverse threads have a core/sheath structure with a first component forming the sheath and a second component forming the core, wherein the first component has a lower melting point than the second component, the first component is a fusible thermoplastic polymer material and the multifilament reinforcing yarns arranged alongside one another are joined together via the first component of the transverse threads by meltbonding.

Abstract: A pre-impregnated yarn including a bundle of reinforcing fiber filaments having a bundle interior and a bundle outer side, a first resin composition, and a second resin composition. The first resin composition includes at least one urethane resin, H1, produced from a reaction of a bifunctional aromatic epoxy compound based on bisphenol A, an aromatic polyisocyanate, and a polyalkylene glycol; an oxyalkylated bisphenol A resin, H2; and aromatic polyhydroxy ether P1. The filaments are impregnated with and at least partially connected via the first resin composition. The first resin composition is present in a concentration of 0.1 to 4 wt % relative to a total weight of the pre-impregnated yarn. The second resin composition is on the bundle outer side in the form of particles or drops adhering to the filaments, and is in a concentration of 0.5 to 14 wt % relative to the total weight of the pre-impregnated yarn.

Abstract: A non-crimp fabric includes at least two superimposed layers made from multifilament reinforcing yarns arranged parallel to each other, and at least one layer made from a non-woven made from thermoplastic polymer material on and/or between the layers made from multifilament reinforcing yarns, wherein the non-woven includes a first polymer component and a second polymer component whose melting temperatures lie below the melting or decomposition temperature of the reinforcing yarns. The first polymer component has a lower melting temperature than the second polymer component, and the first polymer component is soluble in epoxy matrix resins, cyanate ester matrix resins, benzoxazine matrix resins, or mixtures thereof. The second polymer component is not soluble in epoxy matrix resins, cyanate ester matrix resins, benzoxazine matrix resins, or mixtures thereof. A preform is made from the non-crimp fabric.

Abstract: A fiber preform for producing fiber composite structures, a wall thereof including a first zone made from reinforcing fiber bundles having a first resin composition and a second zone made from at least one fiber tape comprising at least one unidirectionally directed reinforcing yarn strand having a second resin composition. The reinforcing fiber bundles in the first zone are oriented in different spatial directions to each other when viewed in a direction parallel to the extension of the thickness. Each reinforcing fiber has a length of from 3 to 50 mm, and contains the first resin composition in a concentration of from 1 to 10 wt % of the fiber weight. The wall of the fiber preform has a proportion of reinforcing fibers of more than 35 vol %, and the second zone forms a discrete region when viewed in a direction perpendicular to the thickness extension of the wall.

Abstract: Carbon fibers and carbon fiber yarn consisting of carbon fibers, the fibers having been pretreated by electrochemical oxidation, characterized in that they have a finish consisting of epoxy resin(s), a vinyl component, and a plasticizer in an amount of 0.3 to 5 wt. % relative to the carbon fibers, which are to be provided with the finish.

Abstract: A pre-impregnated yarn having a bundle made of reinforcing fiber filaments impregnated with a first resin composition infiltrated into the pre-impregnated yarn and at least partially connected via the first resin composition. The first resin composition contains at least two bisphenol A epichlorohydrin resins H1 and H2 in a weight ratio H1:H2 of 1.1 to 1.4, and an aromatic polyhydroxy ether P1. The pre-impregnated yarn has a second resin composition on the bundle outer side in the form of adhesive particles or drops. The second resin composition is solid at ambient temperatures and has a melting temperature in the range from 80 to 150° C. The bundle interior and at least 50% of the surface of the bundle outer side are free of the second resin composition.

Abstract: A process for producing fiber preforms for composite material components makes it possible to directly produce complex geometries in a flexible and low-cost manner by applying a plurality of dry fiber rovings independently of one another even in spatially uneven contours. It is no longer necessary to use cut fabric strips since fiber preforms are produced straight from the dry fiber rovings. This obviates the need to carry out production, transport and order picking processes. It is not necessary to cut fiber strips to size, and therefore a saving may be made on material. In addition, it is possible to increase the mechanical characteristic values in the composite material because it is not necessary to sew fiber webs. The described process can also readily be scaled since the number of dry fiber rovings arranged next to one another make it possible to vary the area which can be covered.

Abstract: A multiaxial non-crimp fabric comprising at least two superimposed layers of multifilament reinforcing yarns arranged within the layers parallel to each other and abutting parallel together. The reinforcing yarns within one layer as well as adjacent layers are connected and secured against each other by sewing threads forming stitches proceeding parallel to and separated from each other at a stitch width w, the sewing threads form stitches with a stitch length s, and the zero-degree direction of the non-crimp fabric is defined by the sewing threads. The reinforcing yarns of the layers are symmetrically arranged in respect to the zero-degree direction of the non-crimp fabric and form an angle ? to the zero-degree direction, the angle not being equal to 90° or 0°, and the sewing threads have a linear density from 10 to 35 dtex.

Abstract: A fiber preform for producing fiber composite structures, a wall thereof including a first zone made from reinforcing fiber bundles having a first resin composition and a second zone made from at least one fiber tape comprising at least one unidirectionally directed reinforcing yarn strand having a second resin composition. The reinforcing fiber bundles in the first zone are oriented in different spatial directions to each other when viewed in a direction parallel to the extension of the thickness. Each reinforcing fiber has a length of from 3 to 50 mm, and contains the first resin composition in a concentration of from 1 to 10 wt % of the fiber weight. The wall of the fiber preform has a proportion of reinforcing fibers of more than 35 vol %, and the second zone forms a discrete region when viewed in a direction perpendicular to the thickness extension of the wall.

Abstract: A fusible lignin has a gas transition temperature in the range between 90 and 160° C. determined using differential scanning calorimetry (DSC), a molar mass distribution with a dispersivity of less than 28, determined using gel permeation chromatography (GPC), an ash content of less than 1 wt. %, and a proportion of volatile components of a maximum of 1 wt. %. Also provided is a precursor fiber based on the fusible lignin, as well as a method for the production thereof Also provided is a method for producing a carbon fiber from the precursor fiber.

Abstract: A multiaxial non-crimp fabric comprising at least two superimposed layers of multifilament reinforcing yarns arranged within the layers parallel to each other and abutting parallel together. The reinforcing yarns within one layer as well as adjacent layers are connected and secured against each other by sewing threads forming stitches proceeding parallel to and separated from each other at a stitch width w, the sewing threads form stitches with a stitch length s, and the zero-degree direction of the non-crimp fabric is defined by the sewing threads. The reinforcing yarns of the layers are symmetrically arranged in respect to the zero-degree direction of the non-crimp fabric and form an angle ? to the zero-degree direction, the angle not being equal to 90° or 0°, and the sewing threads have a linear density from 10 to 35 dtex.

Abstract: A non-crimp fabric includes at least two superimposed layers made from multifilament reinforcing yarns arranged parallel to each other, and at least one layer made from a non-woven made from thermoplastic polymer material on and/or between the layers made from multifilament reinforcing yarns, wherein the non-woven includes a first polymer component and a second polymer component whose melting temperatures lie below the melting or decomposition temperature of the reinforcing yarns. The first polymer component has a lower melting temperature than the second polymer component, and the first polymer component is soluble in epoxy matrix resins, cyanate ester matrix resins, benzoxazine matrix resins, or mixtures thereof. The second polymer component is not soluble in epoxy matrix resins, cyanate ester matrix resins, benzoxazine matrix resins, or mixtures thereof. A preform is made from the non-crimp fabric.

Abstract: A yarn includes reinforcing fiber filaments and a resin that is infiltrated into the yarn and can be repeatedly melted and solidified by cooling to room temperature, wherein the filaments of the yarn are at least partially bound to one another by the resin, wherein the yarn contains 2.5 to 25 wt.% of infiltrated resin relative to its total weight, and wherein the infiltrated resin includes a mixture of at least two epoxy resins E1 and E2, E1 having an epoxy value in the range of 2,000 to 2,300 mmol/kg of resin and E2 having an epoxy value in the range of 500 to 650 mmol/kg of resin, and the weight ratio E1:E2 of the epoxy resins E1 and E2 in the mixture is chosen so that the infiltrated resin mixture has an epoxy value between 550 and 2,100 mmol/kg of resin. A preform comprising the yarn, a method for producing the preform and its use in producing a composite are also described.

Abstract: A method for stabilizing yarns made from polyacrylonitrile using chemical stabilization reactions, including: generating a field of high-frequency electromagnetic waves in an application space of an applicator, which has areas with minimum electric field strength and areas with maximum electric field strength, the maximum electric field strength in the application space being in a range from 3 to 150 kV/m; continuously supplying a precursor yarn based on a polyacrylonitrile polymer into the application space, and conveying the precursor yarn through the application space and through the field of the high-frequency electromagnetic waves; introducing a process gas into the application space and conveying the process gas through the application space with a flow rate of at least 0.1 m/s relative to the precursor yarn being conveyed through the application space, wherein a temperature of the process gas is in a range between 150 and 300° C.

Abstract: A lignin derivative is produced from a lignin with the empirical formula L(OH)z, where L is a lignin without hydroxyl groups, OH are free hydroxyl groups bonded to L, and z is 100% of the free hydroxyl groups bonded to L. The lignin derivative has free hydroxyl groups that are derivatized with divalent residues Rx and monovalent residues Ry that are bonded to L via an ester, ether, or urethane group. A shaped body comprising the lignin derivative can take the form of a fiber, e.g. as precursor fiber for the production of a carbon fiber. A carbon fiber can be produced from the above-mentioned precursor fiber.

Abstract: A composite material is described that contains a reinforcing resin and reinforcing fibers, wherein the reinforcing fibers have a coating containing polyphenylene sulfide and the proportion of polyphenylene sulfide relative to the uncoated fibers is 0.001 to <0.01 wt. %. The composite material shows higher apparent interlaminar shear strength and bending strength as compared with similar composite materials having no PPS coating in the above concentration range.

Abstract: Thread having at least two strands of continuous carbon fiber that are twisted around one another, whereby the carbon fibers of the strands are arranged approximately parallel to the thread direction. The at least two strands of continuous carbon fiber are twisted around one another and produced by direct cabling. A method for the production of the thread includes twisting each of the at least two strands of continuous carbon fiber around one another by direct cabling. An eyelet assembly with an eyelet that has a radius of at least 4 mm in the area of contact between the strands and the eyelet assembly. The thread is used as a sewing thread or a thread for reinforcing polymers, elastomers, rubber or concrete.

Abstract: Carbon fibers and carbon fiber yarn consisting of carbon fibers, the fibers having been pretreated by electrochemical oxidation, characterized in that they have a finish consisting of epoxy resin(s), a vinyl component, and a plasticizer in an amount of 0.3 to 5 wt. % relative to the carbon fibers, which are to be provided with the finish.