Drafting Force in the Front Zone of a Double Apron Drafting System

Abstract

The drafting force was measured in the apron zone of the Casablancas GX-2 drafting system by causing a small deflection in the slubbing being drafted between the aprons at the front rolls. The drafting force increased with the size of the front beard, i.e., with total draft, fiber length, speed of drafting, ambient relative humidity, and regain of the material. The drafting force decreased as the break draft and apron-to-apron spacing increased. There was a difference in the force when the roving was fed in the normal direction and then in the reverse, thus showing that the effect of fiber hooking that originated at the card still persists at the spinning frame. For good spin, a certain amount of fiber tension is necessary at the front draft zone, but an excessive tension of the front beard will not always lead to optimum conditions.