Principle Of Open-end Spinning

The yarn-forming process of open-end spinning usually includes opening, condensing, twisting and winding. First, the fed fiber strips are opened into single fibers by a high-speed rotating combing roller, and some can also be separated into single fibers by a high-speed rotating roller combined with airflow. At this time, the slivers are no longer continuous. The separated single fibers are generally transported by airflow and then condensed to the tail end of the twisted yarn. While condensing, twisting is performed to form yarn. During the condensation process of this free-end spinning, the number of fibers on the yarn tail gradually increases and has a uniform merging effect. During twisting, the yarn tail rotates with the twister. If the twisting point does not coincide with the fiber condensation point and the yarn tail is completely free, the yarn tail will have no twist and is easy to break, making it difficult to spin continuously. Therefore, the general free-end spinning yarn tail should have an appropriate twist to meet the needs of continuous spinning.
In free-end spinning, twisting and winding are carried out separately. The twisting speed is generally above 30,000 rpm, while the winding speed is relatively low. The two are not restricted, and high speed and high yield can be achieved and large packages can be directly wound into bobbins. The pre-spinning of open-end spinning is generally the same as that of ring spinning. In order to strengthen the removal of impurities and dust, rotor spinning requires special pre-spinning equipment.
The conditions for ensuring good quality and reducing spinning ends in open-end spinning are: ① The fiber strips are fully opened into a single fiber state; ② The transportation and coagulation of single fibers require uniformity, and the fibers should be straightened and oriented as much as possible to obtain a coagulated yarn tail with a good geometric structure; ③ The slivers that have been coagulated into a good structure during the twisting process should not be damaged, and the yarn tail should have a certain strength during the twisting to withstand the necessary spinning tension, and the winding shape is good, which is easy to unwind.