Yarn take-off jet at an open-end spinner has structured ring projections at the yarn contact surface to give a progression of the yarn twist to the yarn/fiber bonding point for spinning softer yarns without abrasion

摘要

At the yarn take-off jet from an open-end spinner, the yarn contact surface (32) has a number of projecting rings (36). The flanks of the ring projections (36) form an obtuse angle with the yarn contact surface (32) between them in the direction (f) of yarn travel. The enclosed angle between the flanks of the ring projections (36) and the yarn contact surface (32) is -110 deg . The angle increases towards the end of the ring projections away from the yarn contact surface. The ring projections (36) have a beading shape, a cup shape or they are non-rotating balls inserted into the yarn contact surface with a dia. of 1-4 mm. The ring projections (36) are in a height over the yarn contact surface (32) which is less than one-half of the dia. of the base surface of the projection on the yarn contact surface (32), and is }0.3 mm. The projections (36) extend at least partially over the plane of the end surface of the yarn take-off jet (3) towards the spinning rotor (1). The projections (36) have a steep flank on the trailing side in relation to the direction (f) of yarn travel. The ring projections (36) are distributed evenly over the yarn contact surface (32), and are at least partially in the transit zone (35). The dia. of the projecting rings is close to the dia. of the limit plate (30) at 7-11 mm. The yarn contact surface (32) is fitted with max. eight projections (36) and pref. four. The projections (36) have a wear-resistant and polished surface.