Heat adds volume to the carbon fiber production process
By Enid Burns
December 13, 2011
When the Wright Brothers first took to the skies more than hundred years ago they did so with an aircraft made with a fabric skin. Over the years a variety of materials have been used including sheet metals such as aluminum and titanium, and even ceramics. A fabric of sorts has now returned in the form of carbon fiber, a composite material that offers greater strength-to-weight ratio than virtually anything else. While airplane manufacturers have used carbon fiber in airplanes for some time, its use is on the rise due to the material's durability and rigidity.
Advaero has developed and licensed Heat Vacuum Assisted Resin Transfer Method (HVARTM) to manufacture composite materials. This method takes the typical practice of curing carbon fiber and adds low heat to the process. HVARTM produces 60 or 65 percent more fiber/volume than the typical VARTM carbon fiber production process, although results vary depending on the material weave, resin and other factors.
Carbon fiber produced using the HVARTM process is used to make parts for aircraft, helicopters, and parts used in oil refining. One example of an aircraft application is ducts. Two uses for ducting are internal air ducting inside the aircraft and ducting for jet engine exhaust channels. For the later use, the exhaust ducts channel hot "bleed" air away from the airplane's engines, preventing overheating. It's essential to use a heat-resistant material to withstand the jet engine's high temperatures and repeated use.
Advaero says it's in talks with several major commercial and military aircraft manufacturers interested in the company's techniques for constructing carbon fiber and other composite materials.
Advaero also produces lightweight carbon fiber parts for the U.S. Military for use in its CH-46 helicopters, parts previously made from aluminum. Weight saved by replacing aluminum with carbon fiber allows the helicopters to fly higher and carry more payloads or more troops to and from battle.
Push rods for oil fields are another use for carbon fiber produced by Advaero. The carbon fiber push rods absorb oil leaked into the field (or water). Excess oil is burned off and the rods are able to be reused. Previously a boom made of cotton and human hair was used to collect oil from the ocean. The drawback to the cotton and hair boom is that it needs to be destroyed after it absorbs oil, and is only sufficient for one use.
The increasing demand for carbon fiber is also related to its growing use in the commercial aircraft - namely the Boeing 787 Dreamliner, which just flew into service over the past few months. Each 787 calls for 35 tons of carbon fiber reinforced plastic That's 23 tons of carbon fiber fabric infused with epoxy to construct the rigid material. While Boeing goes to multiple sources for carbon fiber used in the Dreamliner, the Advaero HVARTM method will likely attract the attention of manufacturers given that it results in more carbon fiber being produced with the same amount of material.