Tough static-resistant nylon for electronic applications

09-Jul-15

Successful development of a glass-reinforced polyamide (nylon) with anti-static properties, low-temperature impact strength, dimensional stability and excellent surface-finish has been announced by Clariant. The material was custom compounded by the Clariant Corporation BU Masterbatches Specialty Compounding business in Albion, Mich. It was created to help Advanced Design Concepts, Inc., (ADC), a custom molder in Pewaukee, Wis., to meet a customer’s need for a housing for electronic equipment that must operate safely in potentially explosive environments. Mark Schaefer, Founder and President of ADC, says his firm was asked to produce plastic housings that could meet requirements for ATEX and IECEx certification covering for electronic gear used worldwide in areas with potentially explosive or flammable gases or vapors. The standards require that the plastic housings have a surface resistance of less than 109 ohms at 45 to 55% relative humidity. They also must pass the test after an IP20 drop test at -20F. Finding a supplier of materials that could meet the standards requirements was easy, Schaefer says, but finding one that could supply it in the necessary small quantities was more of a challenge. His customer makes fewer than 1000 devices per year, so being able to get the resin in lots as small as 200 lb. is a big advantage. Schaefer says he had an offer from another company to supply a suitable material he decided Clariant could provide superior value. “We have worked with Clariant in the past and found that they generally give us more help than any other supplier,” Schaefer explains. ADC had been molding housings for non-hazardous applications previously and these were made of a glass-reinforced nylon 66 and Clariant immediately came forward with a similar compounded material that incorporated the company’s permanent antistatic additive to meet the required surface resistivity specifications. The resins’ shrink rate was similar enough to the original material that ADC did not need to modify the molds. Meeting the low-temperature impact requirements was another thing, however. After trying several other formulations, Clariant recommended a material originally developed for use in snowshoes. It is a glass-filled nylon 6 material with the permanent antistatic additive. “I can tell that the material is not as stiff [as a standard-impact nylon],” Schaefer says, “but the average user wouldn’t even notice.”