Weaving Shedding

Other Terms Related to Single Fabrics Weaving Shedding Filling Insertion Beat-Up... 

Figure 4.14 Components of a weaving shed (a) back shed, (b) front shed, (c) top shed,...

Chemists would like to invent molecules that assemble themselves into specific, we 11-organized arrays. Recently there have been some exciting successes. Our inset is a molecular view of a self-assembled molecular wreath. This organized sfructure forms when four molecular chains weave themselves together in the presence of 12 copper cations. Self-assembling molecular systems could lead to new materials with useful properties. They may also shed light on how life originated. 

A versatile size particularly suitable for texturised continuous filament polyester yarns. Produces a tough resilient film with good adhesion to polyester thus reducing the tendency for size to shed from the yarn during weaving whilst eliminating the problem of sized threads sticking to each other or to the beam. 

Heddle he-dsl [prob. alt. of ME helde, fr. OE hefeld akin to ON hafald heddle, OE /zehhaw to lift] (1513) n. A cord, round steel wire, or thin flat steel strip with a loop or eye near the center through which one or more warp threads pass on the loom so that the thread movement may be controlled in weaving. The heddles are held at both ends by the harness frame. They control the weave pattern and shed as the harnesses are raised and lowered during weaving. 

Shedding n. (1) The operation of forming a shed in weaving. (2) A loss of nominal length staple at any process in a staple yarn plant. 

Another type of shell three-dimensional woven textile was suggested in 1929. A combination of Jacquard shed formation and shuttle weft insertion creates a flat woven fabric with areas of double and single layers (Lippert, 1929). Depending on the coti-tour of the double-layer area, this part of fabric can be cut and unfolded after weaving, for example, to become a hat geometry (Figure 4.4). 

The shedding mechanism is one of the primary motions of a loom. A Jacquard shedding mechanism is used for weaving 3D preforms because the individual warp fibers are controlled independently by Jacquard harness cords. A 3D fabric and preforms can be woven on a 2D conventional rapier loom, but there is a fabric thickness limitation when using any conventional 2D loom. 

The movement of the warp during the weaving process causes various stresses and strains (Islam, 1985,1993). The let-off and shedding motions, together with the movements of the back rest roller and of the cloth fell, influence the total warp tension. 

The 2D conventional loom is modified to weave various 3D woven preforms. What kind of modification(s) should be carried out depends on the nature of preforms to be produced. The take-up and shedding motions are modified in many ways along with other tools that are also installed. Modified looms are used to produce thick panels, contour materials, polar materials, and complex 3D preforms. An unlimited number of 3D preforms and complex shapes can be woven on a modified loom with electronic Jacquard. Figure 9.60 shows a narrow fabric shuttle loom weaving a 50-mm-thick carbon panel. An orthogonal weave has been used with a dead pick motion so thatX, Y, and Z fibers are perpendicular to each other. 

---