Basalt Fibers: Alternative To Glass?
High-temperature performance and superior strength properties may make this late-comer a better choice in some applications.
By Anne Ross, Assistant Editor | August 2006
It's burn resistance has earned basalt fiber a role as an asbestos replacement in friction applications, such as composite brake pads, because it does not soften at elevated temperatures and won't deposit on its counterpart (either the disc or brake drum) in the braking system. Continuous basalt fibers also are in use as reinforcement in other conventional composite structures. According to Nolf, basalt fibers wet easily and therefore enable fast resin impregnation, making them suitable for resin transfer molding, infusion molding and pultrusion. "All the products that are made of glass can be made of basalt," Markuts claims.
PROTOTYPE TO PRODUCTION
Mislavsky says that Kammeny Vek currently has several customers using its standard reinforcement products. One company of note is glass fiber manufacturer Ahlstrom (Helsinki, Finland), which is supplying biaxial basalt fabrics for testing in wind turbine blade laminates. "The wind blade business is driven by stiffness," Mislavsky says. Basalt fiber laminates have a 15 percent higher modulus and 25 percent higher tensile strength over E-glass, making its use in some zones of the wind blades ideal. Project engineers use a computerized system to calculate the advantages and disadvantages of different materials and sizings. Prototypes are undergoing a series of tests, and Mislavsky expects the blades to be certified by Germanisher Lloyd later this year.
Source: Kamenny Vek
Three bobbins of continuous-filament basalt roving, ready for transport to a customer.
OEMs are beginning to investigate basalt fiber products for consumer goods as well. Gitzo SA (Nogent Le Phaye, France), which sells professional tripods and heads, recently debuted its basalt tripods and monopods. The company offers several different models to suit the needs of almost any photographer. Gitzo entered composites manufacture with its carbon fiber tripods, and now uses its fiber-reinforced tube fabricating experience to make basalt versions. The company chose basalt fiber because it offers a strong composite at less cost than carbon. Basalt tripod legs are roughly 20 percent lighter than aluminum legs and better at damping vibration.
Lib Technologies (Seattle, Wash.) currently sells two different snowboard models that incorporate a basalt fabric instead of the traditional fiberglass used on many of its models. The boards, manufactured by Mervin Manufacturing (Seattle, Wash.), are part of the company's Dark and Phoenix series and are made with a product the company calls Golden Fleece Basalt, from an unidentified supplier. The boards contain a proprietary wooden core with a basalt fiber lining on each side that results in lighter, stiffer snowboards. Mervin Manufacturing also produced a snowboard for QuikSilver using Basaltex products. The board was on exhibit in the Basaltex booth at the 2005 JEC Composites Show.
In the automotive industry, Azdel Inc. (Southfield, Mich.), a 50/50 joint venture of GE Advanced Materials (Pittsfield, Mass.) and glass-fiber producer PPG Industries (Pittsburgh, Pa.), developed VolcaLite, a thermoformable thermoplastic composite that combines polypropylene (PP) and long chopped basalt fiber. The company claims that the basalt/PP system offers acoustic absorption properties, low coefficient of thermal expansion (CTE), and a high strength-to-weight ratio, providing good ductility. It is initially targeted for auto headliners, which can be made 50 percent thinner than conventional systems, says the company.
Technical Fibre Products Ltd. (Kendal, Cumbria, U.K. and New York, N.Y.) has taken chopped basalt fibers and made gossamer nonwoven veils. The company is running trials of the product in laminated and thermoformed automotive components. Johns Manville Europe (Bad Homburg, Germany) also has produced wet-layed basalt veils.
Basalt fiber is becoming a contender in infrastructure applications as well. Although the company no longer produces its own fiber, Sudaglass (Houston, Texas) produces several products from basalt fiber, including concrete reinforcement rods. Pultruded from unidirectional basalt fiber, the rods are reportedly 89 percent lighter than steel reinforcement rods, have the same coefficient of thermal expansion as concrete and are less susceptible to degradation in an alkaline environment. The company claims that that 1 ton of basalt rods can provide reinforcement equal to 4 tons of steel rods.
As commercialization continues, consistent fiber supply also looks promising. Kamenny Vek, for example, is looking to launch a second furnace later this year and hopes to turn out 30,000 metric tonnes (66 million lb) per annum by 2009, Mislavsky says.
