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 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 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 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: A process for manufacturing bonded laid structures from yarns, characterized in that a thermally fusible material is applied to the yarns at least at the contact or intersection points via a thermal spray process and the yarns are subsequently brought together, as well as a process for manufacturing a fiber-reinforced composite material, characterized in that, initially, laid structures according to the invention are manufactured and subsequently, with the addition of further thermally fusible material if necessary, the structures are molded under heat and pressure into the fiber-reinforced composite material.

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 cord consisting of a core and a sheath is provided, whereby the core contains high-modulus fibres embedded in a matrix and is at least predominantly ensheathed with fibres that form the sheath.