Ku, H. S. and Siu, F. and Siores, E. and Ball, J. A. R. and Blicblau, A. S. (2001) Applications of fixed and variable frequency microwave (VFM) facilities in polymeric materials processing and joining. In: 5th Asia Pacific Conference on Materials Processing, 25 Jun 2001, Seoul, Korea.
Microwave processing of materials is a relatively new technology advancement alternative that provides new approaches for enhancing material properties as well as economic advantages through energy savings and accelerated product development. Factors that hinder the use of microwaves in materials processing are declining, so that prospect for the development of this technology seem to be very promising [Ceram. Bull. 68 (2) (1989) 376]. The two mechanisms of orientation polarisation and interfacial space charge polarisation, together with DC conductivity, form the basis of high frequency heating. Clearly, advantages in utilising microwave technologies for processing materials include penetrating radiation, controlled electric field distribution and selective and volumetric heating. However, the most commonly used facilities for microwave processing materials are of fixed frequency, e.g. 2.45 GHz. This paper presents a state-of-the-art review of microwave technologies, processing methods and industrial applications, using variable frequency microwave (VFM) facilities. This is a new alternative for microwave processing. The technique is geared towards advanced materials processing and chemical synthesis. It offers rapid, uniform and selective heating over a large volume at a high energy coupling efficiency. This is accomplished using a preselected bandwidth sweeping around a central frequency employing frequency agile sources such as travelling wave tubes as the microwave power amplifier. Selective heating of complex samples and industrial scale-up are now viable. During VFM processing, a given frequency of microwaves would only be launched for less than 1 ms.
|Item Type:||Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)|
|Uncontrolled Keywords:||variable frequency microwave; VFM facilities; characterisation; fibre reinforced thermoplastic matrix composite materials; bulk heating; penetrating radiation|
|Subjects:||290000 Engineering and Technology > 291400 Materials Engineering > 291402 Composite Materials|
|Depositing User:||Dr Harry Ku|
|Date Deposited:||11 Oct 2007 01:04|
|Last Modified:||12 Nov 2013 06:59|
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