Working group
Ultrasound is a technique, which presents a low risk or hazard potential to
the individual or the environment and at the same time is suitable for
industrial application. It is not just possible to inspect parts for structural
defects using ultrasound (e.g. cracks), but also to determine the actual
mechanical properties, without impairing or hindering part functionality.
In particular, sensitivity of ultrasound to variations in viscoelastic material
properties, has been employed to develop techniques that can be used to monitor
the flow/cure behaviour of main safety relevant engineering components. The
data can be analysed on-line and is employed for process monitoring and process
control.
An ultrasound pulse is transmitted through various polymer materials, and the received signal is analysed.
By monitoring the signal transmission times and amplitude, the sound velocity and attenuation coefficient is calculated and can be correlated to points of relevance in the production process. This information is summarised and employed to describe the flow and cure behaviour.
The information obtained can be employed to set or maintain machine/mould parameter for consistent production. Furthermore, such information on material mechanical properties is important not just in terms of plastics processing, but also for their later application.
The ultrasound sensors and technology have been developed for investigations of new materials and technologies and can normally be adapted to suit most technological processes. The sensors are the so-called eyes of the system and provide the raw information which enables an operator to visualise (in the process) the given material state.
