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WEB EXCLUSIVE: Dexmet Corp., Wallingford, Conn., a manufacturer of precision expanded metals, foils, and polymers has added Aptiv film to its PolyGrid portfolio, which is made of Victrex PEEK from , West Conshohocken, Pa. Driven by the need to withstand increasingly harsh environments in filtration for the fuel-cell industry, Dexmet chose Aptiv film made with Victrex PEEK, using an expansion procedure with specifically designed proprietary equipment and processes to produce diamond-configured, open-area mesh products. Fuel-cell manufacturers are experimenting with different materials as a membrane substrate to adhere to the catalyst, which is typically a mixture of carbon and platinum, according to Ken Burtt, v.p. of sales and marketing at Dexmet. “They need a material that has a high-temperature capability along with good mechanical strength. As manufacturers increase the performance of their cell, the pressures will increase, and mechanical strength of the membrane will become more critical. Current materials typically used are polyimides and sulfonated TFE but as these materials reach their performance limits, Aptiv film has become the next logical choice.”

 

Dexmet uses a precision expansion process with a “slit and stretch” function to produce the high-performance mesh product. “It’s a process that has been around for over 100 years,” explains Burtt. “What makes it unique to Dexmet is our ability to produce an expanded product using very thin materials with very small openings at wide widths. There are no other expanders in the world that can expand thin materials, especially polymer films under 0.005 in. (0.127 mm) with opening sizes down to 25 microns.” The expansion process doesn’t punch out material to produce the hole, so there is little scrap.