Northwire Inc. is opening new markets for robotic cables that flex, thanks to the use of DuPont Hytrel thermoplastic polyester elastomer for insulation. Meeting a key requirement of manufacturers and end-users robotic and other mobile automation equipment, Northwire recently obtained the first 90 and 105ºC UL recognitions for Hytrel under the UL 758 standard. These are embodied in UL style 10912 AWM.
“Because of its combination of high mechanical strength and dielectric strength, we can use Hytrel in thinner layers than many alternative materials,” said Ted Beach, director of sales for Northwire. In multi-conductor cables, thinner insulation results in a substantial reduction in cable diameter, which means longer flex life at a given bend radius. Slimmer cables can also permit tighter bends while meeting a particular flex life target.
Northwire’s cables for robotics typically use a 0.008 or 0.010 inch (0.20 or 0.25 millimeter) layer of insulation. Although materials such as PVC and polyolefins also provide adequate insulation in thin layers, their mechanical strength is not nearly as good as that of Hytrel, according to Beach. Another advantage for Hytrel is its productivity and stability during extrusion of thin insulation layers.
Northwire is also delivering the benefits of Hytrel in cables that flex in other fields. They range from lift bridges to retractable cables for telescoping antennas on mobile broadcasting vehicles.