FORMATION AND MORPHOLOGY OF TEXTILE FIBER (Fiber Spinning)

Fiber Spinning

Although natural fibers are available a morphological kind determined naturally, regenerated and synthetic fibers may be "tailor-made" counting on the form and dimensions of the opening (spinning jet) that the polymer is forced through to make the fiber. There are many ways wont to spin a fiber from its compound, including melt, dry, wet, emulsion, and suspension spinning. Melt spinning is that the least complex of the methods. The compound from that the fiber is created is melted so forced through a spinneret and into air that causes solidification and fiber formation.

Dry and wet spinning processes involve dissolving the fiber-forming polymer in an applicable solvent, followed by passing a targeted answer (20%-50% polymer) through the spinneret and into dry air to evaporate the solvent within the case of dry spinning, or into a coagulating bathtub to cause precipitation, or regeneration of the polymer in fiber kind within the case of wet spinning. There’s a internet contraction of the spinning answer on loss of solvent. If a skin of polymer is made on the fiber followed by diffusion of the rest of the solvent from the core of the forming fiber, the cross section of the fiber because it contracts might collapse to make an irregular popcorn-like cross section.

Emulsion spinning is employed just for those fiber-forming polymers that are insoluble. Polymer is mixed with a surface-active agent (detergent), and probably a solvent, so mixed at high speed with water to make an emulsion of the polymer. The polymer is skilled the spinneret and into a coagulating bathtub to make the fiber. In suspension spinning, the polymer is swollen and suspended during a swelling solvent. The swollen, suspended polymer is forced through the spinneret into dry hot air to move the solvent or into a wet non-solvent bathtub to cause the fiber to make through coagulation.

Fig: Fiber Cross Section

The spinning method can be divided into 3 steps:

1.                 Flow of spinning fluid within and through the spinneret below high stress and sheer.

2.       Exit of fluid from the spinneret with relief of stress and a rise in volume (ballooning of flow).

3          Elongation of the fluid jet because it is subjected to tensile force because it cools and solidifies with orientation of molecular structure within the fiber.

Common cross sections of synthetic fibers include round, trilobal, pentalobal, dog-bone, and crescent shapes. When 2 polymers are used in fiber formation as in bicomponent or biconstituent fibers, the 2 elements will be arranged during a matrix, side-by-side, or sheath-core configuration. Round cross sections also are found wherever skin formation has caused fiber contraction and puckering (as with rayon) has occurred, or wherever the spinneret form has provided a hollow fiber. Complex fiber cross-sectional shapes with special properties also are used (Fig :).