Fiber crimp

Because fiber frictional properties are so important in the conversion of staple yams to spun yams, ASTM D2612 has been designed to measure the cohesive force encountered in the drafting or fiber alignment of sHver and top under static conditions. This frictional force is affected by surface lubrication, linear density, surface configuration, fiber length, and fiber crimp. 

Control of the regeneration conditions, together with a wide variety of modification, allows the production of a wide variety of products including high-wet modulus fibers, hollow fibers, crimped fibers, and flame-resistant fibers. While almost all rayon is produced using the... 

Mathematical equations were developed to calculated the effective thermal conductivity of pile carpets. The fibers were oriented parallel, perpendicular, and on a diagonal to the carpet foundation and factors such as fineness of filaments, thread count of horizontal and vertical loops, and extent of fiber crimping were related to thermal conductivity (jfc). 

Inspection of the fabric attribute dimensions for all location points revealed that certain attributes were either absent or unrecognizable. These attributes are fiber bundle, fiber single, fiber crimp, fiber surface, fiber pattern, yarn type, and yarn twist direction. Therefore, these attributes were deleted from the statistical analysis. The remaining attributes were either present at all location points or exhibited variation. These attributes included the three (layers, 1/1, and float) whose interactive effects had direct relevance to the research hypothesis, and the following fiber and yarn attributes paired fibers, 0 twist, combined yarns, yarn system A, yarn systems A + B, yarn systems A + B + C + D, fabric distortion, red, green, and black. 

In searching for a fiber that would exhibit these characteristics, the animal-fiber wool and the seed-hair cotton can be discarded. Both of these fibers lack the above-named attributes, for they have molecular and fiber crimp, which would result in less than straight trajectories. Flax and the other bast fibers may be deleted as well, because the fibers within bundles would vary in number. 

Crimp development medium, For testing of textured yarn, an environment that allows the temporary set of fiber crimp to be overcome and that allows the filaments to assume their permanently set configuration. 

Fiber crimp The waviness of a fiber or fabric responsible for void formations. It determines the capacity of fibers to cohere under light pressure. Measure either by the number of crimps, waves per unit length, or the percent increase in extent of the fiber on removal of the crimp. 

Normal fibers Crimped fibers High-wet-strength fibers Polynosic modal fibers... 

Fiber crimp (waviness) affects the ease with which fibers may be spun into yarn, as well as many of the comfort characteristics of cloth made from those yarns. Computerized image analysis techniques can be used to measure the degree of crimp of a fiber. 

Crimp The waviness of a fiber. Crimp can be either natural or can be mechanically or thermally induced. 

Flapper fla-por (ca. 1570) n. The movable side of a fiber-crimping chamber that periodically opens or flaps to permit crimped fiber to be expeUed from the chamber. 

From the cured composite specifications, the fabric AW is calculated, then multiplied by the specified fiber percentages to find the X, Y, and Z components of the total AW. By multiplying the AW components with the appropriate fiber yield, the 3D preform construction for each direction is calculated. Depending on the weave pattern and fiber crimp, the 3D preform construction may need adjusting. 

One of the easiest 3D weave patterns to design is the 3D orthogonal weave pattern because all fibers are straight in the X, Y, or Z directions fiber crimp is minimal and can be eliminated from the calculatiOTis. To calculate the total number of Z yams required per square inch of 3D orthogonally woven preform, the preform thickness must be taken into account. The following equation assumes each Z fiber travels through the entire preform thickness. 

Non-crimp fabrics (NCFs) are manufactured by stitching unidirectional yams in a layer to another layer of unidirectional yarns. If the directions of the yams in the two layers are perpendicular to each other, for example one layer is parallel to the roll direction and the other is perpendicular to it, then the NCF is referred as [0/90°].There may be many other configurations such as [0/90° /0/90°] or [0/907+45° /-45° /90° /Oj. NCF eliminates the fiber crimp, and thus high fiber volume fraction and in-plane mechanical properties can be obtained. 

D weaving The weft yarns are inserted over and under the multiple layers of warp yams. This process yields thicker woven structures than in 2D weaving where only one single layer of warp is used. 3D woven preforms have higher strength in the thickness direction than the 2D woven fabrics however, their strength decreases in the in-plane directions due to the fiber crimp. 

Fiber crimping using a staffer box device may be done before in-line relaxation or before autoclaving. The relaxation process tends to set the crimp. In some autoclave processes, a second crimping step is employed subsequent to relaxation. Fiber may be cut to staple at the machine end for in-line relax processes or batchwise for autoclave processes. Tow can be produced from either process type, although large packages of one ton or more are produced more readily from the in-line relax process. 

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