The investigation into the mechanics and inducement of residual torsion within the beadwire production process

Abstract

National-Standard Co. Ltd. senior management recognised the need to meet the increasing standards in quality being set and demanded by the tyre and automotive industries for products and components being supplied to them for the 1990's. A 2 year project was initiated to investigate the Beadwire final processing and control, to reduce the effects of residual torsion (axial twist) and identify the influences of various elements within the process which affect the quality of the wire, so enabling improved control on product variability and overall consistency. The main phase of the project has been to determine the cause and define the mechanics of residual torsion within the final production process. A theoretical mathematical model of the process showed that there was a connection with the material physical properties i.e. wire diameter & ductility but there was a combination of outside factors that could also influence the amount of residual torsion within the wire. The main significant conclusion formed was that residual torsion phenomenon is elastic in nature rather than a plastic deformation problem. Further experimental work was conducted on the straightening rollers, as this was the only position within the process where the wire could be monitored,travelling at 4m/sec. This highlighted the main factor affecting the process as wire tension, which influences the control of residual torsion within the straightening rollers. Design &implementation of a pneumatic tension control for the let-off system established the improvement in residual torsion control through the straightening rollers.