Host Institutions: The University of Nottingham, University of Edinburgh
Start Date: 1st April, 2020
Duration: 6 months
Lead Investigator: Andrew Parsons
Co-Investigators: Adam Joesbury, Conchur O’Bradaigh, James Murray, Lee Harper
Double diaphragm forming (DDF) is a process for producing complex, large preforms for out of autoclave processes. DDF generally requires lower capital investment compared to matched tool forming, but defects such as fibre bridging and fabric wrinkling are more likely to occur. To improve on this, DDF has been combined with a liquid infusion process, where a dry fabric stack held between two flexible membranes (diaphragms) is infused with resin prior to being formed. There are several benefits for doing this:
(1) The resin infusion step is performed with flat fabric plies, simplifying the filling stage without geometrical constraints.
(2) Forming occurs in the presence of a low viscosity liquid, reducing inter-ply friction and diaphragm-fabric friction, improving fabric conformation to the tool
(3) The infusion and forming stages are combined into one process, saving time and consumables
The project fits within the “high rate deposition and rapid processing technologies” priority area of the Hub and addresses both Grand Challenges. It is also complimentary to a number of existing and prior projects funded by CIMComp, including:
Overall the project delivered on its objectives, but full realisation of the project was limited by travel restrictions due to Covid.