Prediction of interlamellar pearlite spacing of tyre bead wires after patenting using electromagnetic techniques

An attempt has been made to correlate interlamellar pearlite spacing with electromagnetic parameters after the patenting stage (Ø3.1 mm wire) on a tyre bead wire line. Two different techniques were adopted for the above work. One was electromagnetic sorting and the other was measurement of the inductance of a suitable electromagnetic encircling coil at a lower frequency (17.1 Hz). The interlamellar spacing was assessed by the intercept method at a higher magnifcation (×25,000) using a scanning electron microscope. The observed results suggest that the electromagnetic sorting technique was not efficient enough to predict the interlamellar spacing quantitatively, whereas the electromagnetic measurement technique exhibited distinct differences in electromagnetic inductance for samples having different interlamellar spacings. The low-frequency inductance increased with an increase in the interlamellar spacing due to the reduced pinning effect on the magnetic domain wall movement.