Characterisation of thermoset laminates for cosmetic automotive applications: Part I – Surface characterisation

This study concerns the surface quality of coated and uncoated composite laminates intended for use as cosmetic, automotive body panels. A series of laminates were investigated ranging in fabric architecture, resin type and fabrication process. Laminate surface quality was assessed subjectively and used for contextual comparison with two quantitative methods; profilometry and reflectometry, which characterised the type and severity of the features on the laminate surface. Measurable changes in surface quality for varying fabric architecture, matrix contraction and tool surface roughness are used to infer the behaviour of composite laminates. We conclude that the arithmetic mean roughness parameter is suitable for relating bare laminate surface roughness to final paint quality with roughness thresholds being developed. Light reflectometry correlated well with subjective assessment for painted laminates with significant effects seen when varying laminate constituents and tool quality.