摘要 |
A bifilar resistance element for use in preparing heating elements used in thermal bonding and the like, wherein two electrically conducting wires are embedded in a thermoplastic sheath which is fusible when sufficient current is passed through the bifilar resistance element. A heating element is prepared by joining the pair of wires in a length of the bifilar resistance element together at one end to form an electrically conductive path and then winding the length into a spiral shape. Two articles of thermoplastic material may be bonded together by placing the heating element in a recess simultaneously adjacent both articles with a pair of leads to the heating element extending externally from the two articles to be bonded, and applying an electrical current so that the thermoplastic sheath and a portion of the adjacent articles themselves are fused, to bond the articles together upon cooling. |