| Swirl spinning is a new-type spinning process. It uses jet air to process fibers in order to resolve the matters in air-jet spinning. It substitutes roller drafting system with combing roller drafting system, which ensures the drafting system of swirl spinning with high speed, high efficiency, little abrasion, and so on.On the basis of large former experiment and theoretical analysis, loading roller, fiber guiding pipe and fiber-guiding device were designed and the closed swirl spinning process was improved.The flow field's distribution of fiber-guiding device are very important for guilding fiber. A three-dimensional computational fluid dynamics model was developed to simulate the flow field inside the fiber-guiding device with ANSYS CFX. Flowing state, distributing of static pressure and velocity and so on were characterized and analyzed.Finally, results were got as follows:1. Fiber-guiding device working with fiber guiding passage and loading roller can well guild the converged fiber.2. Compressive air through the jet orifice comes into being three-dimensional whirly airflow.3. The reason of twist irregularity of filament is that the tangential velocity at different position is different.4. The axial velocity near the wall is larger,which can draft to the free end wrapped fibers;At the same time it also easily leads to collision among polyester filament yarn, fiber and the wall,and leads to deteriorate of the straight parallel for derived fibers.5. The radial velocity is small and volatile.It makes the edge open-trail end fibers in the main nozzle begin to expand to let filament get more wrapper fibers.6. The negative pressure in the inlet decreases with increasing the jet orifice angle.The tangential velocity increases along with increasing the jet orifice angle.It is better when jet orifice angle is 45 degree.7. When the velocity at the exit of jet orifice enhances, the tangential velocity,the axial velocity and the negative pressure in the inlet are greater.
|
PDF Full Text Request