Test apparatus and method of measuring mar resistance of film or coating
AssigneeE. I. Du Pont de Nemours and Company
InventorLi Lin
Life of this patent
Estimating the term…
Abstract
This invention concerns a test apparatus and procedure used for quantitative and qualitative characterization of scratch and mar behavior of films or coatings, more particularly automotive coatings. The apparatus includes a micro-indentor that penetrates and scratches the coating to be characterized together with interrelated components for measuring the force applied, the length and depth of the indentor penetration, the geometry of the disturbed coating surface as well as a system for measuring, analyzing and comparing test results.
Claims32
An apparatus (1) for measuring mar resistance of a test sample (56) comprising:
- means for indentor guiding (6), said means being mounted on a post (4) of said apparatus (1) comprises:
- means for indentor driving (7) having an indentor (32) positioned therein, and means for sensing travel (9) of said indentor towards and away from a surface of said test sample;
- and
- means for directing said test sample, said means being positioned on a base (2) of said apparatus comprising:
- holder means (13) to secure said test sample (56) thereon with the surface of said test sample (56) in perpendicular relationship with said indentor (32), and staging means (11) for traversing said test sample in a direction tangential to said indentor, such that when a tip of said indentor (32) is simultaneously driven into said test sample, a scratch is produced on the surface of said test sample.
A method of measuring mar resistance of a test sample (56) comprising:
- securing said test sample (56) in staging means (11) of an apparatus (1);
- positioning an indentor (32) in a perpendicular relationship to an exposed surface of said test sample (56), such that a tip of said indentor (32) is in contact with said surface of said test sample (56);
- and
- driving said tip of said indentor (32) into the surface of said test sample (56) at a set rate while simultaneously traversing said test sample (56) in a direction tangential to said indentor (32) at a set speed in a set direction for scratching said surface of said test sample (56) to produce a scratch thereon.
A method of measuring mar resistance of a test sample (56) comprising:
- securing said test sample (56) in staging means (11) of an apparatus (1);
- positioning an indentor (32) in a perpendicular relationship to the exposed surface of said test sample (56), such that a tip of said indentor (32) is in contact with said surface of said test sample (56);
- profiling the surface of said test sample (56) for a set distance by traversing said tip over said test sample (56) in a direction tangential to said indentor (32) in a set direction and storing pre-scratch profile data resulting therefrom;
- driving said tip of said indentor (32) into the surface of said test sample (56) at a set rate while simultaneously traversing said test sample (56) in a direction tangential to said indentor (32) at a set speed in said set direction for said set distance obtained by referencing said pre-scratch profile data to produce a scratch on said surface of said test sample (56), and storing tip-displacement profile data resulting therefrom;
- profiling the scratch on the surface of said test sample (56) by traversing said tip over the scratch in a direction tangential to said indentor (32) in said set direction for said set distance and storing post-scratch profile data resulting therefrom;
- processing said pre-scratch, said tip-displacement and said post-scratch profile data;
- and
- displaying the processed data in a visual or graphic form.
Dependencies are inferred from the claim text.