Structurally enhanced preformed layers of multiple rigid unidirectional rods are constructed and arranged for use in fabricating load-bearing support structures and reinforcements in a variety of composite components, e.g. wind turbine blades. Individual preform layers include multiple elongate unidirectional strength elements or rods arranged in a single layer along a longitudinal axis of the preform layer. Individual rods include aligned unidirectional structural fibers embedded within a matrix resin such that the rods have a substantially uniform distribution of fibers and high degree of fiber collimation. The relative straightness of the fibers and fiber collimation provide rods and the preform layers with high rigidity and significant compression strength. A plurality of rods are loosely attached, e.g. knitted, together with a coupling that allows for each rod to be axially displaced, e.g. slideable, relative to another rod.

The invention is an improved macrosynthetic fiber for concrete reinforcement.

Disclosed is an apparatus and method for forming three-dimensional woven preforms that can be curved and have continuous fibers in the direction of curvature. Also disclosed are woven preforms formed thereby.

Provided are a cellulose fiber containing cellulose II, the cellulose fiber having improved heat resistance, as well as a fiber reinforced resin composition, a method for producing the cellulose fiber, and a method for producing the fiber reinforced resin composition. The cellulose fiber contains the cellulose II having a content of an imidazolium salt of 1% by mass or less.

A sleeve roll belt (10) has an inner surface (11) and an outer surface (12). The belt has a body (15) and a reinforcing structure (30). The reinforcing structure (30) has first yarns (31) arranged to a first direction (D1) of the belt, and second yarns (32) arranged to a second direction (D2) of the belt. The reinforcing structure (30) also has auxiliary yarns (31b, 31c) arranged parallel or substantially parallel to the first direction (D1) of the belt, wherein the auxiliary yarns are arranged to a depth of greater than a depth of the first yarns, measured from the outer surface (12) of the body (15) to an outer surface (31-o, 31b-o) of each yarn (31, 31b, 31c) in the depth direction of the belt, and a diameter of the auxiliary yarns is at least 20% smaller than a diameter of the first yarns.

Provided is a glass cloth obtained by weaving a glass thread, which is made from a plurality of glass filaments, as a warp and weft. The average filament diameter of the glass filaments is 3.0-4.5 μm. The respective weaving densities of the warp and the weft constituting the glass cloth are, independently, 70-130 threads/25 mm. The standard deviation of weft width of the glass cloth is not more than 30 μm. The weft covering ratio R, which is represented by the expression R=Y/(25400/D) (where R is the weft covering ratio, Y is the average weft width, and D is the well weaving density) satisfies the relational expression 0.50≤R≤0.83.

A woven article for a carbon fiber reinforced plastic according to the present invention is a woven article of a spun yarn containing: about 10 wt % to about 60 wt % of a carbon fiber staple in which the content of carbon components is equal to or greater than about 97 wt %; and about 40 wt % to about 90 wt % of a thermoplastic resin fiber, wherein the carbon fiber staple is obtained by carbonizing carbon fiber reinforced plastic scrap at a temperature of about 900 to about 1400° C. The woven article for a carbon fiber reinforced plastic includes a carbon fiber staple manufactured from scrap generated during manufacture of the carbon fiber reinforced plastic, and allows economic recycling of the carbon fiber reinforced plastic scrap without a reduction in mechanical properties. When molded, productivity is high due to a short cycle time, there is almost no orientation, and an excellent flexural modulus is exhibited.

A fiber preform for use in a resin transfer molding or liquid composite molding process and process of making the same are provided. The preform includes a substrate, a fiber bundle arranged on the substrate in a predetermined pattern and attached to the substrate by a plurality of stitches of a thread. The fiber preform is capable of being pre-formed into a three-dimensional shape. The fiber preform along with a sheet of preformed thermoset resin that impregnates at least a portion of the fiber preform forms a composite material. The fiber preform reinforces areas of stress concentration of a core to form a vehicle component.

A fiber structure includes a plurality of weft layers and a plurality of warp layers interlinked with three-dimensional or multilayer weaving, the fiber structure including at least first and second portions that are adjacent in the warp direction, the first portion presenting thickness in a direction perpendicular to the warp and weft directions that is greater than the thickness of the second portion. The weft layers situated in the core of the first portion of the fiber structure include braids. The weft layers extending on either side of the weft layers including the braids and going as far as the skin of the first portion include yarns or strands, the braids presenting a section greater than the section of the yarns or strands.

Methods to increase structural performance, strength, and durability of textile-reinforced composite materials are provided. The textile reinforcement may be knitted, for example, in a flat bed weft knitting machine. The method may include pre-stressing a textile reinforcement preform by applying tension. A polymeric precursor may be introduced to the pre-stressed textile reinforcement preform. The polymeric precursor may then be cured or consolidated, followed by releasing of the applied tension to form the composite article comprising polymer and the pre-stressed textile reinforcement. In other aspects, a composite article is provided that has a pre-stressed textile reinforcement structure and a cured polymer. The textile reinforcement may be a knitted, lightweight, seamless, unitary structure. The knitted reinforcement structure may have distinct first and second knitted regions with different levels of pre-stress, thus providing enhanced control over strength, rigidity, and flexibility of the composite article.