Braiding yarns

Ultrapure silica or quartz fibers are used in fabrics, yams, rovings and threads. Fabrics are used to reinforce radomes, antenna windows for missiles, high temperature circuit boards, and rocket nose cones. Braided yarns provide high temperature electrical insulation, e.g., for coaxial cables, thermocouple wires, and space separators. Rovings are used to reinforce polymer matrix composites for ablative and electrical uses, as well as high performance sporting goods, e.g., tennis racquets and skis, especially when hybridized with carbon fibers. Threads are used to stitch cable tray insulation for nuclear power plants. 

Braid angle n. The acute angle measured from the axis of a fabric or rope to a braiding yarn. 

Figure 10.19 Braid architecture (a) Localization of the braiding yarn, middle-end yarn, and core yarn for one pitch length, (b) The fiber path for one braid plait is represented by a cosine.

The pultmsion of preform no. 1 was early intemipted owing to jute/PLA MEY breakage inside the pultmsion die when the L thickness was reduced from 6.7 to 6.1 mm. The pultmsion of preform no. 2 also intermpted for the same reason when the I thickness at exit was reduced to 4.0 mm The pultrusion no. 3 and 4 were performed without problems with a final L thickness of 3.2 mm. In both experiments, the closing of the dies was stopped because of apparent jute/PLA braiding yarn breakage that was observed on the beams after the die exit Table 10.5 shows all the measurements of the beams after pultrusion. 

Apart from the inner structure, braids can also be classified into biaxial and triax-ial structures (Fig. 7.3). A biaxial braid only consists of the two braiding yarn systems of which the braid is made. Triaxial braids have in addition an axial thread (0° or stationary thread) integrated in the production direction in any place within the braid. 

Depending on the crossing of the braiding yarns, a wide range of different patterns can be produced, as shown in Fig. 7.5. In the axial direction, reinforcing yarns can be used (right). 

Nylons belong to the class of polymers known as engineering polymers that is, they are strong, tough, and heat resistant. We can readily extrude and mold nylons to form a wide variety of useful objects, such as tubing, furniture casters, and automotive air intake ducts. Nylons are commonly spun into filaments or fibers. These can be used directly, or braided, or twisted to form threads, yarns, cords, and ropes, which may be further woven to make fabrics. In their fibrous forms, nylons are used in carpets, backpacks, and hosiery. 

Braid. To enclose in criss-crossing yarns of textile. 

D reinforcing products mats, woven or knitted fabrics, braidings from yarns or rovings. 

In Vitro and In Vivo Degradation of Pofy(Lrlactide) Braided Multifilament Yarns... 

The polymer was extruded at 240 C to produce 28-strand multifilament yarn. The yam was hot-stretched and fiber tensile strengths in the range 3-6 g/den (1-2 dpf) could be obtained. The yam was placed on braider bobbins on a 12-carrier machine with 7-ply core. The braid was made with 51 picks per inch and hot-stretched 25% at215 F. 

Is a nonionic self-dispersing lubricant for narrow fabrics, and a yarn lubricant for braiding and weaving. Colorless, and will resist any yellowing. 

A2 + E2) Commingling Interweaving, braiding Mixed yarn Textile fabric Filament winding, pultrusion Hot pressing, pultrusion Yes... 

Meanwhile Etliicon (and otiiers) developed alternative absorbable surgical sutures, based, for example, on copolymers of polyglycolide with poly-L-lactide or poly(trimethylene carbonate), and on polydioxanone, and on poly(s-oxycaproate), and also on copolymers of tliese with polyglycolide or with each otlier. These different structures made it possible to provide fibres with different rates of absorption, with different degrees of stiffness or flexibility, and for use in monofilaments, braided multifilaments, and other yarn structures, as required for different surgical operations. 

The sheath strands are also twisted from yarn. They are braided into a cylindrical sheath, around the core. The braiding process (Fig. 15.5) is analogous to a maypole dance. As the clockwise dancers pass in and out of the anticlockwise dancer, their ribbons braid around the pole. There are between 24 (half in clockwise and half anticlockwise) and 44 strands in the rope sheath. Manufacturers may quote the number of bobbins, from which the strands are unwound. A large number means the strands are finer. The bobbins transfer from rotor to rotor, so they make circuits of the core. 

Conversion of material from yarn to fabric (weaving or knitting or braiding)... 

Fiber, textile Fibers or filaments that can be processed into yarn or made into a fabric by interlacing in a variety of methods, including weaving, knitting, and braiding. These forms of textile are used with plastics to fabricate parts such as high strength tubes/pipes, electrical and medical devices, etc. 

During prepregging (Fig. 6) the woven-, braided- or non-erimped fabric textile gets coated with resin. Afterwards the composite - now called prepreg - gets heated up to lower the viseosity of the resin. Thus, the resin can penetrate into the yam. Heated or unheated squeeze rollers can full the resin more over into the yarn and force the penetration. Depending on the maehine and the produeer... 

LAS glass-ceramic matrix composite reinforced by 3-D braid Nicalon yarns and SiC monofdaments in (he axial direction. Tensile strength 656 MPa Aerospace [2]... 

---