Delphi and GE’s new wire insulation is based on Noryl PPO, but that’s only part of the story. Keith DuPont, GE Advanced Materials program director, notes that Noryl is always “PPO plus something else.” Without an added thermoplastic, “PPO would flow like cement,” he explains. Other Noryl products have used alloy partners such as nylon or polystyrene. In the case of Flexible Noryl, all DuPont will say is that the material is an alloy of PPO and an olefin.
Then there’s a proprietary collection of additives to impart end use properties, such as flame retardants and lubricants. DuPont won’t say much about these either, but he does note that Noryl gets by with lower loadings of flame retardants. “That’s because the PPO molecule is a natural char former,” he says. Finding the right alloy materials and additives took GE and Delphi engineers about three years. DuPont says the company evaluated over 200 formulations using computerized chemical design tools. Delphi ultimately evaluated more than 20 real-world formulations before settling on a handful of compounds it can use for wire insulation. Beyond automotive wiring, GE has also developed Flexible Noryl compounds for use in consumer electronics and appliance applications. Riki Kojima, the company’s global director for electronics, says Flexible Noryl has gotten some attention in the consumer electronics industry because it ties in with the OEM’s ongoing plans to get rid of halogenated plastics, like PVC. “We already have some commercial successes in Asia,” he says, noting that LTK, a large Hong Kong-based wire manufacturer now offers wire coated with Flexible Noryl (see www.ltkcable.com for more information).Wire coated with Flexible Noryl has the same VW-1 UL-1581 flame rating as PVC, according to Chisato Suganuma, GE Advanced Materials’ electronics industry manager. . “Flame retardant PE and TPU do not pass that test,” he says. In terms of its bending performance, he adds, the Flexible Noryl wire has passed flexibility tests devised by GE’s electronics customers. One such test requires 6,000 bending cycles with no loss of mechanical properties. GE’s consumer electronics customers in Asia have already used or will soon use the wire for a variety of internal wire applications for cell phones, computers, MP3 players, televisions, printers, and more. Other applications include external wires, such as those used for audio-visual equipment. Appliance customers have also expressed interest in the wire, Kojima says.