ALPHARETTA, Ga., October 5, 2010 – Solvay Advanced Polymers’ reformulated Ixef® BXT 2000-0203 polyarylamide (PARA) blow molding resin has been approved by the California Air Resources Board (CARB) and the U.S. Environmental Protection Agency (EPA) as a barrier solution for three-layer fuel tank systems for lawnmowers, snow blowers, weed trimmers, generators, and other small off-road equipment. CARB executive order Q-08-025 states that OEMs can use the material without the need to undergo costly and lengthy tank permeation testing. Fuel tanks using this three-layer design have also been approved by EPA.
The company expects the material technology to be commercialized for the first time in a three-layer tank by a leading U.S. lawn and garden equipment supplier by the first quarter of 2011.
“This significant regulatory milestone positions Ixef resin as a new solution for OEMs who seek to reduce hydrocarbon emissions and meet CARB and EPA standards,” said Duane Fish, technical marketing engineer for Solvay Advanced Polymers. Three-layer fuel tanks blow molded of HDPE and Ixef BXT 2000-0203 offer simplicity and reduced cost versus competing multilayer and fluorinated systems and also meet SAE J233 (minus 40°F cold impact test).
Ixef BXT 2000-0203 resin exceeds the current CARB TP901 standard, which limits fuel vapor emissions to 1.5 g/m2/day for small off-road engines, and the new EPA regulation for fuel CE10. The fuel-resistant barrier material also maintains its mechanical properties in new fuels such as bio-diesel and ethanol-based mixtures. It is also easier to process than the previous grade, offering a lower processing temperature, higher flow, and a wider processing window.
To meet barrier requirements, three-layer extrusion-blow molded tanks consisting of HDPE/Ixef/HDPE can be manufactured instead of coextruded five-layer HDPE/EVOH tanks. Three-layer HDPE/Ixef tanks afford processing simplicity, reduced equipment and tooling requirements, and lower cost compared to traditional five-layer HDPE/EVOH structures. They also offer better cold weather durability and cost less than monolayer solutions which contain more expensive barrier additives. HDPE/Ixef tanks are also less costly than fluorinated tanks which must be shipped back and forth to a treatment facility.
Unlike EVOH, which is limited to continuous-extrusion blow molding, Ixef BXT 2000-0203 can be run on both accumulator and continuous-extrusion machines. For blow molded HDPE/Ixef tanks, no purging is required and changeovers on both machines are quicker and less costly than with EVOH, according to Fish.
Solvay also noted that Ixef BXT 2000-0203 resin can be used as a barrier solution in two-layer structures with HDPE because it can withstand direct-fuel contact in applications such as fuel lines, filler pipes, low-permeation fuel hoses, and other fuel system components. Other different types of layered structures such as two-layer configurations are also being examined to meet specific product demands.
