Out-of-autoclave (OOA) manufacturing expands composite opportunities by offering cheaper processes with more size options.

Out-of-autoclave (OOA) manufacturing has grown as a way to process next-generation structures, particularly in the aerospace industry. But what is leading manufacturers to adopt OOA, especially considering they’ve already invested so much capital in autoclave systems? It boils down to two main factors – money and part size. Traditional autoclave curing systems are expensive to buy and operate and are available in limited sizes.

Manufacturers in aerospace and other industries are increasingly turning to OOA to cure parts only in an oven. Out-of-autoclave is less capital-intensive and less costly, especially as parts increase in size and number. Several of the latest advancements push the technology even further, offering curing solutions that are out-of-autoclave and out-of-the-oven. Among the solutions under development are integral liquid heating/cooling and induction heating. These technologies offer the same benefits of OOA and then some – fewer steps, less material and shorter cycle times.

The Argument for Out-of-Autoclave

OOA is most heavily utilized by aerospace industry manufacturers. However, seen as a solution to the drawbacks of autoclave processing, a variety of sectors are adopting OOA methods, from renewable energy to automotive and consumer electronics. They hope to improve their products, increase throughput, cut down on production time, and decrease capital, operating and labor costs.

Autoclaves are capital intensive: The price of a single autoclave often runs six figures. Those costs can skyrocket even higher, particularly in aerospace where bigger parts lead to larger autoclaves and larger price tags. “In 2007, NASA looked into what it would cost to acquire a 40-foot diameter autoclave, and the cost came out to $100 million, including installation,” says John Russell, technical director of the Manufacturing and Industrial Technologies Division at the Air Force Research Laboratory. “For parts that aren’t frequently replicated, that is a cost we can’t justify.”

Dale Brosius, president of Quickstep Composites in Dayton, Ohio, says autoclave also has long turn around and cycle times, which takes expensive equipment out of the equation for too long, further increasing costs for manufacturers. This applies to new parts as well as part repairs. “Bonder/heater configurations are more economical through focused and localized heating of a repaired part,” says Eric Casterline, president of HEATCON Composites Systems in Seattle. “OOA avoids heating the whole part (automobile, aircraft etc.) during a repair operation.”