| 摘要 |
<p>A communications cable (20) having superior electrical characteristics and meeting the burn requirements for plenum applications has a core (22) formed of one or more twisted pairs (24-30) having a primary insulation formed of a suitable material, such as high density polyethylene. The core is surrounded by an inner jacket (32) formed of a low smoke polyvinyl chloride material. As an alternative to or in addition to the inner jacket, the core may be surrounded by a core wrap (23) having adequate electrical properties and burn/flame resistance properties. The inner jacket is surrounded by an outer jacket (34) comprising a material having excellent heat/flame resistance characteristics but which may have less than optimal electrical characteristics, such as a thermoplastic halogenated polymer, for example polyvinylidine fluoride material. A plurality of cores surrounded by individual core wraps and/or inner jackets may be surrounded by the outer jacket.</p> |
