12 March 2004
12 March 2004
Centek, developers of wet marine exhaust systems, have produced a new range based on high performance fibre-reinforced polymer composite.
The composite is engineered to resist the corrosive nature of the raw water and exhaust gas mixture that is injected into the system to muffle sound and provide cooling. The closest material alternative to composite is stainless steel which costs significantly more and has lower sound-dampening properties.
The company’s latest improvement in materials technology has been a conversion to Vipel K190 chlorendic polyester resin manufactured by AOC. Vipel K190 polyester is part of resin, fibreglass and adhesive material package put together by Jerry Smith, sales representative for distributor Composites One.
“Compared to the resin we used previously, Vipel K190 chlorendic resin goes further toward meeting the stringent performance requirements for the application,” says Ken Harstel, Centek Vice President of Operations. “We are especially impressed with the resin’s ability to achieve recognition for flame retardance per the ASTM-D-635 standard as well as exceeding the US Navy/USCG MIL-R-21607 and MIL-R-7575 specifications. Initial test results with Vipel K190 were so good that we ordered evaluations from both UL and an independent testing lab to crosscheck the data.” In addition to being UL-listed, Centek products are certified as meeting American Bureau of Shipping specifications.
Composites made with Vipel 190 resin are rated to perform at temperatures as high as 350 degrees Fahrenheit F (175 degrees Celsius). Vipel K190 also provides resistance to corrosion, especially for oceangoing vessels with muffler systems that mix exhaust gases with highly alkaline seawater.
AOC’s technical support team helped tailor formulations to Centek’s composite capabilities which include hand lay-up, filament winding, resin transfer molding (RTM) and RTM light. “For all our processes, wet out of the glass fibre reinforcement is much better,” Harstel says. “And shrinkage with the Vipel material is significantly reduced.”
“Centek provided AOC with the kind of application development challenge that brings out the best in our Corrosion Team,” says Emilio Oramas, Business Manager Open Mold Reinforced for AOC. “Working with Centek exemplifies AOC’s commitment to offer corrosion fabricators the complete package of technology, quality and support.”