Abstract
Double covered yarn is produced by a double covering machine equipped with hundreds pairs of upper and lower hollow spindles. Drawing Spandex to be a core yarn of covered yarn into the hollow spindles is so complicated that its automation is especially desired. So, we developed an automatic drawing-in apparatus that could draw Spandex in both upper and lower hollow spindles simultaneously. Results obtained are as follows: (1) The automatic drawing-in apparatus is comprised of both an injector and an ejector. Spandex was drawn into the lower spindle by the injection flow driven by the injector and was drawn from the upper spindle by the suction flow driven by the ejector.
(2) The auto-doffing apparatus developed for a model covering machine performed draw-in. It could draw-in 20 D Spandex that was widely used and was too thin to be easily drawn-in even by a manual doffing operation. So, this confirmed that the developed auto-doffing apparatus had practical utility in the drawing-in operation. (3) The rates of success of Spandex drawing-in are influenced by the supplied air pressures for the injector and ejector and the feed rate of Spandex. High rate of success could be accomplished by the proper adjustment of those conditions.
