Processes for making high-performance polyethylene multi-filament yarn are disclosed which include the steps of a) making a solution of ultra-high molar mass polyethylene in a solvent; b) spinning of the solution through a spinplate containing at least 5 spinholes into an air-gap to form fluid filaments, while applying a draw ratio DR.sub.fluid; c) cooling the fluid filaments to form solvent-containing gel filaments; d) removing at least partly the solvent from the filaments; and e) drawing the filaments in at least one step before, during and/or after said solvent removing, while applying a draw ratio DR.sub.solid of at least 4, wherein in step b) each spinhole comprises a contraction zone of specific dimension and a downstream zone of diameter Dn and length Dn with Ln/Dn of from 0 to at most 25, to result in a draw ratio DR.sub.fluid=DR.sub.sp*DR.sub.ag of at least 150, wherein DR.sub.sp is the draw ratio in the spinholes and DR.sub.ag is the draw ratio in the air-gap, with DR.sub.sp being greater than 1 and DR.sub.ag at least 1. High-performance polyethylene multifilament yarn, and semi-finished or end-use products containing said yarn, especially to ropes and ballistic-resistant composites, are also disclosed.

A macro fiber for a composite article may include a plurality of inner fibers. Each one of the inner fibers may have an inner fiber final cross-sectional size of less than approximately 100 nanometers. The inner fibers may be surrounded by matrix material.

Structural panels and methods of making composite material for such structural panels may include applying a resin to a nonwoven fibrous web, where the nonwoven fibrous web includes a combination of glass fibers and polymer fibers. The web may be dried at a first stage temperature at or below a curing temperature of the resin for a time sufficient to substantially dry but not substantially cure the resin. The web may be laminated at a second stage temperature sufficient to fully cure the resin to produce a composite material. The second stage temperature may be above the melting point of the polymer fibers, and the resin may cause the composite material to retain a substantially rigid shape upon completion of the laminating operation.

Processes for making high-performance polyethylene multi-filament yarn are disclosed which include the steps of a) making a solution of ultra-high molar mass polyethylene in a solvent; b) spinning of the solution through a spinplate containing at least 5 spinholes into an air-gap to form fluid filaments, while applying a draw ratio DR.sub.fluid; c) cooling the fluid filaments to form solvent-containing gel filaments; d) removing at least partly the solvent from the filaments; and e) drawing the filaments in at least one step before, during and/or after said solvent removing, while applying a draw ratio DR.sub.solid of at least 4, wherein in step b) each spinhole comprises a contraction zone of specific dimension and a downstream zone of diameter Dn and length Dn with Ln/Dn of from 0 to at most 25, to result in a draw ratio DR.sub.fluid=DR.sub.sp*DR.sub.ag of at least 150, wherein DR.sub.sp is the draw ratio in the spinholes and DR.sub.ag is the draw ratio in the air-gap, with DR.sub.sp being greater than 1 and DR.sub.ag at least 1. High-performance polyethylene multifilament yarn, and semi-finished or end-use products containing said yarn, especially to ropes and ballistic-resistant composites, are also disclosed.

This relates to a composite structural element, in particular a rib or a spar, specifically for use in a torsion box of an aircraft structure such as a vertical tailplane, wherein the structural element defines a coordinate system with a first axis “a” wherein the structural element comprises a substantially planar main section defining a coordinate system with a first axis “a” extending along the longitudinal axis “L” of the structural element and a second axis “b” extending perpendicular to said longitudinal axis “L” within the planar main section and defining an angle of +90° with the first axis “a”, wherein the structural element contains a lay-up of single plies consisting of a fiber-reinforced composite material with a substantially unidirectional fiber orientation.

The present invention relates especially to an intermediate material comprising, or even constituted exclusively by, an array of individualised ribbons, each ribbon being composed by a tape of unidirectional reinforcing fibres associated, by adhesion, on each of its faces with a veil of thermoplastic fibres, characterised in that the ribbons are disposed in successive layers, in such a way that the ribbons of two successive layers are superposed with or without crossing but without interlacement, the bond between a ribbon and the ribbon or ribbons with which it is superposed being ensured by adhesion, and in that in each layer the ribbons are disposed substantially parallel to each other over at least the major part of their length, while being independent and spaced from each other and in that the ribbons of at least two layers extend in two different directions.

Fabrication of ballistic resistant fibrous composites having improved ballistic resistance properties. More particularly, ballistic resistant fibrous composites having high interlaminar lap shear strength between component fiber plies or fiber layers, which correlates to low composite backface signature. The high lap shear strength, low backface signature composites are useful for the production of hard armor articles, including helmet armor.

A fiber reinforced composite, a component for a wind turbine and a method for manufacturing a component for a wind turbine are provided. The fiber reinforced composite includes a plurality of first fibers, the first fibers being arranged in a unidirectional or biax-configuration, a plurality of second fibers, the second fibers being arranged perpendicularly with respect to a lengthwise direction of the first fibers, and a resin impregnating the first and second fibers, wherein a E-modulus of the resin equals an E-modulus of the second fibers. Since the E-modulus of the resin and the E-modulus of the second fibers are equal, an early initiation of fatigue cracks is avoided.

Fibrous structures that exhibit a Geometric Mean Elongation of greater than 14.85% as measured according to the Elongation Test Method are provided.

High tenacity, high elongation multi-filament polymeric tapes as well as ballistic resistant fabrics, composites and articles made therefrom. The tapes are fabricated from multi-filament fibers/yarns that are twisted together, bonded together, compressed and flattened.