Bayer MaterialScience LLC (Pittsburgh, Pa., USa) reported on Aug. 15 new research demonstrates that a resin transfer molding (RTM) manufacturing process combined with a customizable composite polyurethane system can accelerate production times over the traditional filament winding process/epoxy approach for producing pressurized storage vessels. The RTM/polyurethane approach results in shorter cycle times of less than 20 minutes and provides improved damage tolerance with excellent fatigue and mechanical properties.
Profile Composites (Sidney, British Columbia, Canada) CEO Geoffrey Wood is highlighting test results demonstrating these and other advantages of the RTM process during his presentation, “A new methodology for damage-tolerant composites applied to composite pressurized vessels” Wednesday, Aug. 15, during Composites Conference 2012 (Las Cruces, N.M., USA).
Profile Composites is the lead on the project with funding assistance provided by the U.S. Department of Energy and the U.S. Department of Transportation. Project support is provided by A&P Technology (Cicinnati, Ohio, USA), Bayer MaterialScience LLC, National Center for Manufacturing Sciences, Parker Hannifin and Toray Carbon Fibers America (Flower Mound, Texas, USA). Bayer provided the polyurethane resin and also material processing support.
“The properties of Bayer’s customized polyurethane resin allowed us to achieve a controlled viscosity during the resin injection cycle, and rapid initialization and cure, as well as excellent fatigue and damage tolerance properties,” Wood says. “We’re delighted to be working with Bayer and our other collaborators on this advanced technology.”
Standard filament winding uses a single wet fiber pre-coated with a resin to methodically wrap a spinning mandrel end-to-end. The quicker RTM process deploys a completely dry one-piece fiber mat or mesh to wrap the mandrel or mold, followed by a brief, one-shot resin injection process.
The technology is being demonstrated for vessels with capacities ranging from 7.5 to 40 liters. Potential applications include use in automotive and aerospace vehicles that require high-pressure hydraulic fluid and pneumatic gas storage. After successfully demonstrating the repeatability and process quality of this technology, the next stage is obtaining performance and certification standards before commercialization, according to Wood.