Fiber spinning processes involved

In actuality, fiber-spinning processes involve multifilament spinning. Pick one of the treatments of Chapter 11 and extend it to the multifilament case. 

The mathematical formulation of the fiber-spinning process is meant to simulate and predict the hydrodynamics of the process and the relationship between spinning conditions and fiber structure. It involves rapid extensional deformation, heat transfer to the surrounding quenching environment, air drag on the filament surface, crystallization under rapid axial-orientation, and nonisothermal conditions. 

The carbon fiber production process involves a series of steps including spinning of the precursor fiber, stabilization, carbonization, and post-carbonization treatments that include sizing and surface treatments. The specifics of these steps vary greatly, depending on the precursor material and the desired properties of the carbon fiber. Figure 4 shows a schematic of the carbon fiber production process. 

Heat treatment increases the crystallinity of the core (211,213). The magnitude of the skin-core differences is believed to result from the dry-jet wet spinning process involving diffusion of the solvent and fiber coagulation. 

It has already been pointed out that naturally occurring cellulose does not have a solvent and its modification is necessary for it to dissolve in one. In certain applications, it is desired to prepare cellulose films or fibers. This process involves first reacting it to render it soluble, then casting film or spinning fibers, and, finally, regenerating the cellulose. Regenerated cellulose (or rayon)... 

Control of polymer purity and curability are the critical areas for future work. Some purity requirements will become quantified as this discussion proceeds. With regard to fiber cure, gas-phase chemical cure and energetic methods have been most effective to date 16,18). Fiber processing involving the dry spinning of thermally unstable polymers 4,11,19) may be of future importance, because the need for a separate cure step is eliminated. 

Spinning conditions affect membrane physical dimensions and morphology, which in turn influence membrane performance such as permeability. A satisfactory spinning process would produce fibers having the requisite surface pore size and mechanical strength. Parameters involved in a spinning process are ... 

Spinning processes are mostly involved with fiber separation, ventilation, and guidance that require mechanical and air movements. Production purposed, air conditioning and ventilation purposed machinery and systems of spinning lines are reported as electric energy-intensive processes. 

The processes that occur in the spinline, between the exit of the polymer from the spinneret and the point of stress isolation on the first godet or roller at the base of the spin line, involve the changing of this fluid network to the solid-state molecular chain topology of the filament. Within a distance of 3 5 m, and under the influence of an applied force (take-up tension) and quench media, at speeds in excess of 100 miles per hour—less than 0.01 sec residence time—the fiber is transformed from a fluid network to a highly interconnected semicrystalline morphology, characterized by the amount, size, shape, and net orientation... 

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