Researchers at the University of Warwick Process Technology Group (Coventry, England; (+)44-120-352-4200) have devised a technique for manufacturing spun-fiber based ceramics. The process creates high-tech ceramic fibers without creating small-diameter fibers that can be a health risk. The process is likely to impact applications involving aircraft, mobile phones, furnaces, and other products.
How It's Done
How It's Done (Back to Top)
Fine ceramic fibers have been used for many years because fineness is a desirable property in a range of applications. Unlike the bulk forms of ceramics, fine fibers are strong and flexible. Unlike coarser fibers, they do not scratch and irritate the skin.
Despite these favorable traits, the fibers raise several serious health risks. Ceramic fibers finer than 1 micron in diameter are now known to be carcinogenic; fibers finer than 3 microns are respired into the lungs. Processes that create these fine fibers produce fibers in an assortment of diameters. Even the best current materials contain a large proportion of fibers that can be respired. Some products contain both dangerously fine and irritatingly coarse fibers, creating an even larger health risk for manufacturers and installers.
A research team of chemical engineers, materials scientists, and chemists at the Warwick Process Technology Group have devised a way to achieve the desirable properties of fine ceramic fibers in a safe product. The new process creates a range of high-tech ceramic materials free from dangerously fine, or irritatingly coarse, fibers.
Ashok Bhattacharya of Warwick Unviersity and a research assistant examine the results of the ceramic manufacturing process.
The Fibers Research Group at Warwick uses a Sol-Gel blow-spinning technique that is configured to produce very even fibers. None of the fibers that are created are less than 3 microns in diameter. By focusing on the formation of the spinning sol, the researchers can make fibers of magnetic, piezoelectric, and conductive ceramics, as well as the high-temperature refractory fibers usually associated with ceramic processing.
Applications (Back to Top)
The ceramic fibers can be used for a host of applications, from forming the walls of high-temperature furnaces to acting as lightweight components in planes and cars. They can also be incorporated into composites that are tougher and more user-friendly than existing materials. Fine fibers have excellent thermal insulation properties and good thermal shock resistance, and do not crumple when heated and cooled repeatedly. In the home, they are used in artificial coal for gas fires and around the heating elements on hot plates.
Additional applications include:
- Heat-resistant materials for use in high-temperature furnaces
- Materials that shield microwaves for mobile phones and other applications
- High-performance lightweight components for the automobile and aerospace industries
- Magnetic, piezoelectric, and conductive fibers for composite materials
- Medical implants and artificial muscles
For more information, call Ashok Bhattacharya of the University of Warwick at (+) 44-120-352-4200.