Nanoclay compounds offer improved barrier properties

July 2006

US speciality compounder RTP Company has developed new nanoclay compounds designed to meet the stringent barrier demands in fuel system applications.

The company says that the new nanoclay compounds can provide a monolayer solution for small engine and fuel tank manufacturers to meet the new fuel emission standards for recreational vehicles and lawn and garden equipment. The nanocomposites are claimed to perform exceptionally well in these fuel tank applications due to large aspect ratio layers creating an extremely tortuous path for diffusion.

The new fuel emission standards were set forth by the US Environmental Protection Agency (EPA), which limits emissions to 1.5 g/m2/day starting with the 2008 model year for recreational vehicles. The California Air Resource Board (CARB) also has new regulations which limit emissions to 2.5 g/m2/day starting in 2007 for small off road engines.

The company explains that nanocomposite compounds contain organically-treated clay that separates into nanometre-sized platelets and disperses evenly throughout the resin. The additive has a large aspect ratio that is key to the compound’s unique properties - particularly barrier enhancement in which transmission rates can improve by 2-4 times.