An Experimental Investigation of the Air Drag on Monofilament Fibers and Flowfield Behavior Resulting from Two Convergent High Velocity Jets: Melt Blowing Application

An extensive experimental investigation has been conducted in order to better understand the air drag phenomena of a monofilament fiber in a free jet flowfield. The resulting flowfield was generated from two convergent high velocity jets. This particular arrangement is similar to the meltblown configuration used in the production of nonwoven materials. The experimental data in the results show how the fiber drag varies with stagnation pressure, air injection angle, fiber length, test section orientation, die setback, and exit velocity. A Fanno flow analysis was used to model the flow in the injection nozzles to determine the exit velocity.

The free jet flowfield was also investigated by measuring velocity distributions and by flow visualization. The velocity profiles were obtained using a hot film anemometer. Two optical systems and a smoke system were used in the flow visualization. The shadowgraph and schlieren systems were the optical systems used in the investigation. The jet spread angle and velocity distributions are compared with a classical solution.