METHOD FOR MAKING BICOMPONENT FILAMENTS; TRANSITION TUBE FOR USE IN MAKING BICOMPONENT FILAMENTS

摘要

The method for making bicomponent filaments from two spin dopes wherein the dopes are assembled into alternating layers in a feed tube leading to a transition tube connected to a conventional spinnerette, the layers then being fed through the transition tube and the spinnerette to form filaments. The feed tube has a constant cross-sectional area along the length thereof and the transition tube has a parabolic configuration such that the linear flow rate of the assembled dope layers passing through the transition tube decreases at a uniform rate as the cross-sectional area of the stream of assembled layers is increased to the cross-sectional area of the spinnerette, to thereby maintain the distinctness of the interfaces of the layers and thus insure that good bicomponent filaments will be formed.