![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
In this communication the results obtained during the introduction of statistical quality control techniques into six mills with more than 100,000 cotton spinning spindles, and 1,500 looms are described.
A brief description of the control methods employed, and the particular manufacturing processes used in each mill are given. The improvements obtained by the application of quality control are studied, in particular, the progressive improvement in quality as expressed by the deviation of the yarn count obtained from that required by the specification, the quality as expressed by percentage mean range (P.M.R.), and the coefficient of variation between selected yarn lengths. The study includes the complete sequence of processes from pickers and lap machines, through carding, drawing, roving to spinning. The results are compared and discussed together with the suitabilities of the several spinning processes used for the materials employed—cotton, staple rayon and mixtures.
In the application of control techniques to weaving, the methods adopted for the control of fabric weight with the consequent improvements are described. Finally, a new statistical control technique is suggested to deal with defects and a commercial control that is now applied to the manufacture of cotton velveteens and fabrics for military use is described.