Processing of polymer matrix composites using variable frequency microwave (VFM)

Abstract

[Abstract]: Microwave processing of polymeric matrix composite 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. However, the most commonly used facilities for microwave processing materials are of fixed frequency microwaves (FFM), eg 915 MHz and 2.45 GHz. This paper presents a review of microwave technologies, processing methods and industrial applications, using variable frequency microwave (VFM) facilities. The technique 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 tunable frequency sources. Successful applications of these modern facilities by the authors include the characterisation of glass or carbon fibre reinforced thermoplastic matrix composites, the characterisation of primers, eg two-part five-minute rapid araldite, and the joining of the above mentioned composite materials with, or without, primers.