| 摘要 |
<p>Disclosed is a method of radiation grafting a shape retaining jacket (32) made from an elastomeric polyurethane to an olefinic semi-conductive composition (30) electrically interconnecting at least two elongate spaced-apart conductors (28) to provide an improved, flexible, elongate semi-conductive heating cable (8) that is provided with improved mechanical and electrical integrity and diminished imperfections and improved handling characteristics by reason of a substantially improved bond between the jacket (32) and the olefinic semi-conductive composition (30) arising from radiation grafting in a process that includes a means (14) of oxidizing the outer surface of the semi-conductive composition (30) in combination with application of vacuum able to draw the jacket (32) against the semi-conductive composition (30) within not more than about one and one-half inches from the exit (26) of a die head (4) through which the product (6) is passed.</p> |
