Dr Heather O’Connor
Postdoctoral Researcher

Heather is a postdoctoral researcher in the Materials Processing Development area of I-Form. She submitted her PhD on polymer composite processing technologies in May 2019, in the school of Chemical and Bioprocess Engineering. Her undergraduate degree was in Chemical Sciences, awarded from TUD (previously DIT). Prior to her PhD, Heather gained R&D experience working in the areas of automotive coatings and adhesives research, in both Henkel Düsseldorf and Henkel Dublin. Her research interests include additive manufacturing, polymer composite material and coating/surface technologies.

Research Interests (Lay Summary)

Polymer composite materials refer to plastics, reinforced with fibres or particles. These reinforcements give the composite superior material properties in comparison to unreinforced plastics and metals. They are widely used in aerospace, marine and the automotive sectors. 3D printing of polymer composites is gaining interest as a processing technique due to its high design freedom, short lead time and reduction in waste. However, the strength of these printed polymer composite materials is not as high as when using traditional manufacturing methods. Heather’s PhD research addresses this issue and investigates new ways of printing polymer composites with increased strength.

 

Technical Summary

Polymer composite materials hold many advantages over their steel counterparts; including excellent strength to weight ratio, fatigue and corrosion resistance. The objective of Heather’s PhD research is to evaluate novel polymer composite processing technologies to yield enhanced mechanical performance. One such method involved printing continuous carbon, glass and Kevlar reinforced polyamide composites, inside a vacuum chamber at 1 Pa. The use of low-pressure conditions yielded a significant increase in the mechanical strength of the composite. This is due to a reduction in the heat loss during processing and a reduction in adsorbed gases present, in comparison to printing under atmospheric conditions, which leads to reduced porosity. Enhanced fibre-matrix bonding due to a reduction of voids in the prints was achieved.

The level of porosity reduction obtained was 5.7, 1.0 and 1.7 % for carbon, glass and Kevlar fibre reinforced polyamide parts and the corresponding increase in mechanical performance observed was 33, 22 and 12% respectively. This processing technology has enormous potential in the printing of high temperature, high performance thermoplastic composite materials.

Expertise

Additive Manufacturing (3D Printing), Composite Materials, Fused Deposition Modeling (FDM), Materials Characterisation, Metrology, Plasma Treatment, Powder Bed Fusion, Selective Laser Sintering (SLS), Surface Engineering, Vat Photopolymerisation

Publications