Applied Felts set out to develop a product that would remove the unwanted odors and emissions associated with CIPP lining with styrene-based resins. The result is EnviroCure liners, a heat-cured styrene impermeable polymer coating.

“The proprietary multilayer felt liner coated with a styrene barrier vastly reduces, if not eliminates, styrene odors and emissions on the job site before, during and after CIPP installations,” says Gil Carroll, director of business development for the Rawson Group, which includes Applied Felts, Max Liner and FerraTex Solutions. “EnviroCure provides a safer and inexpensive option for using styrene resin systems for mainline CIPP installs.”

EnviroCure liners are a polyester felt with multilayering coating containing polyamide and can be used with pipe bends up to 45 degrees. To accommodate the requirement for liners of varying thickness, multiple layers of polyester felt can be used.

The liners feature a welded or stitched seam with stitched liners available up to 24 inches in diameter. Welded seam liners offer diameter ranges from 6 to 120 inches for hot cure inversion and 6 to 72 inches for hot cure drag-in. Hot cure inversion can be done in any length while hot cure drag-in is limited up to 300 feet.

Manufacturing of EnviroCure liners didn’t happen overnight, but rather took years of planning and research. “Over five years of development and extensive resources were dedicated to this initiative,” Carroll says.  

Not only was research conducted by the company, outside sources also tested the liners for emission output. “In October 2021, Indiana University–Purdue University Indianapolis tested the EnviroCure liner and concluded that it reduces on-site styrene emissions to less than 1 ppb,” Carroll says. “Further installation tests and studies have shown similar results.”

Carroll also says the biggest benefits reported include the air monitors registering styrene levels well below the 20 ppb acceptable thresholds. “Our sense of smell is even more acute and sensitive, and job site feedback has told us there aren’t any detectable odors in refrigerated transport trucks when doors are opened, or in steam flumes or manholes.”

Liners are manufactured to internal standard or customer specifications and each one is tested for density distribution and gauge at various pressures, resistance to stretch, coating adhesion and ability to weld, weld strengths and sealing tape weld strength before shipping to customers. 276-656-1904; www.appliedfelts.com