Measure of the degree of crystallinty of a polymer coating on a metal substrate
AssigneeArcelorMittal
InventorsNathalie Labbe, Morgan Ferte
Life of this patent
Estimating the term…
Abstract
A method and a measuring equipment of the degree of crystallinity of a polymer coating on a metallic substrate using a hyperspectral camera as well as representing or mapping the degree of crystallinity is provided. An equipment for online measurement of crystallinity of polymers, including at least one hyperspectral camera, at least one lighting source, a polymer layer deposited on a substrate and means to convey the substrate, the lighting source and the hyperspectral camera being set-up in specular reflection towards the polymer layer.
Claims23
A process for mapping a degree of crystallinity of a polymer coating of a moving metallic substrate, the process comprising the following steps:
- a) lighting a transversal area of the polymer coating encompassing a full width with a polychromatic light including wavelengths in the infrared domain;
- b) measuring with at least one hyperspectral camera:
- a light intensity S_(impacted,λα) at a predetermined wavelength λα impacted by the degree of crystallinity of the coating in the infrared domain and
- a light intensity S_(stable,λβ) at a predetermined wavelength λβ not impacted by the degree of crystallinity of the coating in the infrared domain;
- of at least two light beams B1, B2 from the polychromatic light after reflection on the moving metallic substrate at two different locations L1, L2 within the transversal area;
- c) determining at least an impacted absorbance Aimp, using the light intensity S_(impacted,λα) at the predetermined wavelength λα impacted by the degree of crystallinity for each beam B1, B2;
- d) determining at least a stable absorbance Asta, using the light intensity S_(stable,λβ) at the predetermined wavelength λβ not impacted by the degree of crystallinity for each beam B1, B2;
- e) determining, for each beam B1, B2, a ratio, R, equal to Aimp/Asta
- f) converting each ratio R to a determined degree of crystallinity;
- g) mapping the determined degree of crystallinity of the polymer coating in the transversal area using the degree of crystallinity and the locations (L1, L2).
Equipment for online measurement of crystallinity degree of a polymer coating on a moving metallic substrate, comprising:
- at least one hyperspectral camera;
- at least one polychromatic light emitter;
- and
- a substrate conveyor, the polychromatic light emitter and the hyperspectral camera being set-up in specular reflection towards the metallic substrate;
- the at least one polychromatic light emitter arranged to light a transversal area of the polymer coating encompassing a full width with a polychromatic light including wavelengths in the infrared domain on the moving metallic substrate;
- the at least one hyperspectral camera configured to measure:
- a light intensity S_(impacted,λα) at a predetermined wavelength λα impacted by the degree of crystallinity of the coating in the infrared domain and
- a light intensity S_(stable,λβ) at a predetermined wavelength λβ not impacted by the degree of crystallinity of the coating in the infrared domain,
- of at least two light beams B1, B2 from the polychromatic light after reflection on the moving metallic substrate at two different locations L1, L2 within the transversal area;
- the substrate conveyor configured to move the metallic substrate.
Dependencies are inferred from the claim text.