158 (#214) ############################################ WOOLLEN AND WORSTED SPINNING Below 20 skeins the increase in output will be affected by : (a) Increase in thickness of the yarn spun (increased output); (6) Increased proportion of time taken in more frequent doffing (decreased output). Above 20 skeins the decrease in output will be affected by :- (a) Decrease in thickness of the yarn spun (decreased output); (6) Increased twist necessary (decreased output); (c) Proportion of time taken in less frequent doffing (increased relative output). The calculations for 5, 10, 20, 40 and 80 skeins are graphed in Fig. 51 (b). The most practical frame and mule output curves should be plotted together to give a good idea of relative production. The production of the mule will also vary :- (a) in proportion to the number of spindles; (6) length of draw; and (c) several varying influences affecting its number of draws per minute. These matters, however, will usually be readily allowed for and the necessary data obtained with the necessary accuracy for each particular blend. * 本 ​The Folding or Twisting of Woollen Yarns. The principles involved in twisting are fully dealt with in Chapter XII (p. 289), but special reference to the limita- tions of folding or twisting in the case of woollen yarn is here called for. The problem involved may best be considered in list form under the headings " in favour of” and “ against.” 158
102 102 Textile Machine
121 121 Textile Machine
133 133 Textile Machine Part