Clariant has announced successful development of a glass-reinforced polyamide (nylon) with anti-static properties, low-temperature impact strength, dimensional stability and excellent surface-finish. 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. 

“Most nylons that are formulated for good impact properties at low temperatures tend to be much softer,” notes Schaefer, “and we originally thought we might need to thicken walls, add ribs and do other things to make [the housings] stiff enough, but we didn’t need to.”

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.”

Clariant’s broad-based expertise was just as important when it came to coloring the housings. The original housings (without the anti-static qualities) were molded in blue and black. The new ATEX- and IECEx-compliant housings are produced with orange instead of blue. Clariant sells ADC its custom compound in black and natural, and the plan was to color the natural resin using an orange masterbatch. Schaefer says ADC initially went to another supplier for the masterbatch, but found that the color actually bled out of the molded components. “So we asked Clariant to supply one of their masterbatches and that fixed the problem,” he recalls. 

Clariant specialty compounding experts draw on decades of experience with resins, colorants and additives to deliver an ideal solution. Their knowledge extends from material selection to compounding to processing and Clariant’s non-material-biased approach to problem solving allows them the autonomy to choose from a full range of ingredients for any application. Technical competence, along with stringent quality assurance programs, advanced manufacturing capabilities, all add up to make Clariant Masterbatches specialty compounding unit an excellent source for high-performance resin solutions.

The new ATEX- and IECEx-compliant products have been on the market for almost a year and Schaefer says ADC’s customer is pleased with how they have been received. “The products have met the needs of the market and I think everyone has been pleased with their operation.”