Internal strain in yarn package and its control method.

Abstract

The effectiveness of tension control method is made clear by measuring the internal strain and the shape in end faces of the two yarn packages. One is formed according to the theoretical tension curve which makes the residual circumferential stress to be same for all yarn layers, and the other is formed under constant winding tension. Tension controller manufactured in this experiment can form yarn packages according to winding tension of arbitrary theoretical curve from the internal yarn layer to the external yarn layer. In the yarn package formed under controlled winding tension on the assumption that the degree of anisotropy in the nylon-6 yarn package is in the range from 0.36 to 0.50, bulge and cob-webbing of the eng faces of it are smaller than the yarn package formed under constant winding tension. The values and distributions of internal strain, and unwinding tension for the yarn package formed under controlled winding tension, are smaller than ones of the yarn package formed under constant winding tension.