| 摘要 |
In a difficulty combustible cable consisting of plastic insulated core conductors and a plastic sheath, of improved electrical properties and/or smaller dimensions, the core conductor insulation consists of a material of low dielectric constant such as polyethylene, foamed polyethylene or polypropylene, while the cable sheath consists of a mixture contg. PVC which has an oxygen index rising from 32 with decreasing weight ratio of sheath material to core conductor insulating material, and pref. when this weight ratio is =3.0:1 the oxygen index of the sheathe material is >=32, while if the ratio is =1.5:1, the oxygen index is >=35. The cable while retaining its non-flammable properties has much improved electrical properties making is partic. suitable for high duty telephone cables. |
