| The ring-spinning frame is one of the major sources of occupational noise exposure in the textile industry. A search of the literature produced no systematic investigation of the total spinning-frame noise problem though there had been investigations of some of the machine components. Using the methods of source modification and narrow-band frequency analysis, several frames were investigated to determine the existing noise sources, their frequency characteristics, and their relative importance as related to specific machine design and operating characteristics. The most important noise sources were found to be the spindle-bobbin system, the ring-traveller system, and the vacuum-end-collection system. Though not usually dominant, noise was found to be associated with the operation of the idler pulleys, drive tapes, gears, drive cylinder, and motor. An experimental and analytical sutdy was made of the noise of the spindle-bobbin system with emphasis on the oil-lubricated type spindle. This resulted in the development of an elastometic mounting which can significantly reduce the noise of these spindles. The analytical study of spindle vibrations by the finite element method resulted in a new understanding of the mechanism of generation of high-frequency spindle-bobbin noise related to resonant frequencies of the system. These results are related to the design of new spindles. The study of ring-traveller noise resulted in the identification of resonant vibrations of the ring as a part of the ring noise generation mechanism. In order to test and demonstrate the methods of noise analysis developed, and the feasibility of noise control, four spinning frames in actual textile mills were analyzed and modified. A method was developed to relate the single frame results to room noise levels. A different set of noise control modifications was required on each frame due to differences in design and operating conditions. Emphasis was placed on modifications to achieve an acceptable noise level at minimum cost. Three of the four frames were quieted to the desired level within the established cost guidelines. In the fourth case it was found that it would be necessary to replace the spindles in order to reach the desired goal. |
