226 (#298) ############################################ WOOLLEN AND WORSTED SPINNING For reasons which may be readily thought out, the control of the bobbin in cone drawing is utilized to drive it faster than the flyer-considerably faster at the commencement of a draw and gradually slower and slower as it increases in diameter. Examination of the “open” and cone ” drawn slivers usually reveals the latter as more open and some- times more regular. But in comparing the two systems the fundamental questions are- 1. Is twist control during drafting an advantage or a detriment ? 2. If twist control is an advantage, to what extent does it (a) strengthen the sliver so that no straining takes place during either delivery or feed ? (b) allow the use of reasonably large bobbins ? (c) ultimately lend itself, if required, to the pro- duction of a full, lofty-handling hosiery yarn ? If twist control were always perfectly decided and exercised it is probable that cone drawing would show little, if any, advantage over open drawing, save in the possibility of employing larger bobbins for the finer slivers. The deterrent complexities of the " cone-box" as compared with the open-box” will be fully realized on referring to pp. 204 to 206. One other matter still requires consideration, viz., the laying of the coils of sliver one against the other by the action of the lifter-plate or rail. It is obvious that here there are three possibilities 1. To lay the coils of sliver exactly side by side. 2. To make no attempt to lay the coils of sliver side by side. 226
228 228 Textile Machine Part
188 188 Textile Machine
193 193 Textile Machine
127 127 Textile Machine Part