Composite materials, flexible wiring

There has been an increasing global trend in the wire and cable industry to restrict and remove the presence of lead in materials used for insulation and jacketing applications. The various standards that apply to lead in electrical applications are discussed. One of the issues is how to define the low levels of lead. Many minerals contain trace levels of lead as a chemical impurity. These minerals are used in rubber and plastics and thus the final composition is likely to contain trace amounts of lead. With modem analytical techniques, lead can be found at levels lower than five parts per million. Therefore, to satisfy increasing demands on wire and cable materials, a new series of thermoplastic vulcanisates (TPV) has been introduced that contains no added lead chemicals. These TPV materials have recently been granted a UL listing for flexible cord applications. The properties of these materials are presented and highlighted. 6 refs. 

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