摘要 |
Heat-recoverable electrical devices, particularly for covering telephone and other cable splices, comprise (a) a component composed of a PTC conductive polymer which has little or no cross-linking, (2) an adjacent heat-recoverable component composed of a PTC or ZTC conductive polymer which has a relatively high level of cross-linking, and (3) electrodes which can be connected to a power supply so that current passes through the components and causes recover of the device. Preferably a continuous laminar PTC component having little or no crosslinking is sandwiched between two crosslinked continuous laminar ZTC components. Such a device is illustrated in Figure 1. |