Sound orientated fibres in composites

The project’s goal is to show that ultrasonic alignment of fibres can be used in sheet moulding compound (SMC) based manufacturing to tailor the alignment of fibres in pressed components. Controlling fibre alignment is essential to controlling composite properties and much of the work on SMC is on done on this. Ultrasonic alignment has the potential to be a system that can be integrated into existing automated system of SMC manufacturing allowing the rapid, online adjustment of fibres before and during a the pressing of a component. This means that the fibres orientation within the SMC can be adjusted in a way that is not currently possible and through this, the material can be adapted to different designs and integrated with other materials without the need for changing the SMC material or press tool. Ultrasound transducers are also relatively cheap and can be integrated into difference parts of the manufacturing process, once accurate modelling of the wave propagation has been achieved. The project solves a technical problem but the solution has far reaching consequences on the way composites can be manufactured. Hence, the project meets the goals of increasing the sustainability and competitiveness of, in particular, the Swedish car industry, where high volume manufacturing of composite materials is essential for cost effective lightweighting. The theory has been tested in short fibre composites in the UK on a lab scale but manipulating fibres with ultrasound at high volume and flow rates has been developed at LTU for a number of years. Hence transferring this knowledge to high volume composite manufacturing using Swerea SICOMP competence in composite is an innovative idea with great potential for industry.  The project is establishing the degree of orientation that can be achieved with ultrasound in high volume fraction suspension of fibres, combining results from simulations and experiments (see picture). The project will then go on to test this with a resin system. The final part of the project will be to test this in-situ with tools that are used for composite manufacturing.  The results will also be used to assess the feasibility of the application to automotive manufacturing procedures.

Working in the project are LTU’s acoustic group, who have extensive experience of working with fibre suspensions and with ultrasound control and simulation and Swerea SICOMP who research in composite materials and their manufacture and are currently setting up systems for high volume composite manufacturing. Also in the project are Composite Services Europe who are highly skilled in composite manufacturing and have local facilities for producing parts with short fibre composites and CEVT who will be contributing with their experience of the automotive industry in particular with respect to their goals and requirements for component parts.