Improvements in and relating to the production of artificial threads by dry spinning

摘要

Artificial threads are produced by forming a number of filaments by a dry-spinning process in a spinning cell, withdrawing the bundle of filaments so formed from the cell, passing the bundle over and in contact with only a portion of the peripheral surface of a fixed and nonrotatable rod which is substantially at right angles to the path of the filaments, so that the bundle is formed into a ribbon of substantially parallel filaments, and then collecting the bundle of filaments as a twisted thread. The spinning machine may be provided with two brackets into which the rod may be dropped when required, the rod being heavy enough to maintain its position during operation against the forces exerted by the filament bundle. A single rod may be used for contacting all the threads in a conventional battery of spinning units. In the example, a cellulose acetate solution is extruded into a spinning cell, and the thread from the cell is passed over a one-inch diameter steel bar placed horizontally at right angles to the path of the thread so that, after the thread has left the cell but before it passes over a godet, it is in contact with the rod over approximately a quarter of its circumference. The thread then passes over an oiling device and is collected on a ring-spinning machine. The process increases the uniformity of the twist of the thread, particularly when spinning threads of low denier in long spinning cells, e.g. 5 to 10 feet long.