Sliver separation is an essential operation in open-end spinning. Ideally, the sliver should be separated down to individual fibers, each of which is transported in a fully extended configuration. In reality, however, fiber behavior is far from ideal. Because yarn properties are affected by the effective fiber length, alignment of fibers in the air flow should be achieved and maintained, and the fibers must be delivered onto the spinning surface of the spinner in a parallel, well oriented condition. To obtain straight fibers in the air flow to the twisting process, the fibers must be removed in a straightened form, or straightened during removal, from the pin-clothing of the opening roller.