TY - GEN

T1 - Applications of optical coherence tomography in the non-contact assessment of automotive paints

AU - Lawman, Samuel

AU - Zhang, Jinke

AU - Williams, Bryan M.

AU - Zheng, Yalin

AU - Shen, Yao Chun

PY - 2017/6/25

Y1 - 2017/6/25

N2 - The multiple layer paint systems on modern cars serve two end purposes, they firstly protect against corrosion and secondly give the desired visual appearance. To ensure consistent corrosion protection and appearance, suitable Quality Assurance (QA) measures on the final product are required. Various (layer thickness and consistency, layer composition, flake statistics, surface profile and layer dryness) parameters are of importance, each with specific techniques that can measure one or some of them but no technique that can measure all or most of them. Optical Coherence Tomography (OCT) is a 3D imaging technique with micrometre resolution. Since 2016, OCT measurements of layer thickness and consistency, layer composition fingerprint and flake statistics have been reported. In this paper we demonstrate two more novel applications of OCT to automotive paints. Firstly, we use OCT to quantify unwanted surface texture, which leads to an "orange peel" visual defect. This was done by measuring the surface profiles of automotive paints, with an unoptimised precision of 37 nm over lateral range of 7 mm, to quantify texture of less than 500 nm. Secondly, we demonstrate that OCT can measure how dry a coating layer is by measuring how fast it is still shrinking quasiinstantaneously, using Fourier phase sensitivity.

AB - The multiple layer paint systems on modern cars serve two end purposes, they firstly protect against corrosion and secondly give the desired visual appearance. To ensure consistent corrosion protection and appearance, suitable Quality Assurance (QA) measures on the final product are required. Various (layer thickness and consistency, layer composition, flake statistics, surface profile and layer dryness) parameters are of importance, each with specific techniques that can measure one or some of them but no technique that can measure all or most of them. Optical Coherence Tomography (OCT) is a 3D imaging technique with micrometre resolution. Since 2016, OCT measurements of layer thickness and consistency, layer composition fingerprint and flake statistics have been reported. In this paper we demonstrate two more novel applications of OCT to automotive paints. Firstly, we use OCT to quantify unwanted surface texture, which leads to an "orange peel" visual defect. This was done by measuring the surface profiles of automotive paints, with an unoptimised precision of 37 nm over lateral range of 7 mm, to quantify texture of less than 500 nm. Secondly, we demonstrate that OCT can measure how dry a coating layer is by measuring how fast it is still shrinking quasiinstantaneously, using Fourier phase sensitivity.

KW - automotive

KW - car

KW - coatings

KW - drying

KW - functional imaging

KW - Optical Coherence Tomography

KW - phase sensitivity

KW - profilometry

U2 - 10.1117/12.2270020

DO - 10.1117/12.2270020

M3 - Conference contribution/Paper

AN - SCOPUS:85029159123

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Optical Measurement Systems for Industrial Inspection X

A2 - Lehmann, Peter

A2 - Goncalves, Armando Albertazzi

A2 - Osten, Wolfgang

PB - SPIE

T2 - Optical Measurement Systems for Industrial Inspection X 2017

Y2 - 26 June 2017 through 29 June 2017

ER -