Paint Film Scratch Tester
A Paint Film Scratch Tester is a precision instrument designed to evaluate the scratch resistance of coatings, paints, and surface finishes. Compliant with international standards, it measures the critical load required to damage a film, aiding quality control in automotive, aerospace, and consumer goods industries. This article outlines its applicable standards, technical parameters, and operational principles, offering a concise guide for material engineers and lab technicians seeking reliable scratch performance data.
Applicable Standards
The tester adheres to globally recognized norms, ensuring consistency in test results:
| Standard | Application |
|---|---|
| ISO 1518 | Paints and varnishes - Scratch test |
| ASTM D7027 | Scratch resistance of organic coatings |
| GB/T 9279 | Chinese standard for coating scratch |
| BS EN 13523-11 | European coating durability tests |
Main Parameters
Key specifications define the tester’s performance:
| Parameter | Range/Value |
|---|---|
| Test Force | 1–50 N (adjustable) |
| Scratch Speed | 10–200 mm/min (variable) |
| Stylus Tip Radius | 0.5 mm / 1.0 mm (optional) |
| Sample Size | Up to 200×100 mm |
| Data Output | Force-displacement curve |
Working Principle
The device operates by dragging a diamond stylus (tip radius 0.5–1 mm) across the coated surface under controlled force. A motorized stage ensures linear movement, while a load cell monitors applied force. During testing, the stylus progressively increases pressure until visible damage (e.g., cracking, delamination) occurs. The critical load at this point determines the coating’s scratch resistance.
Test Principle
The test evaluates two failure modes:
- Elastic-Plastic Deformation: Measures the force required to permanently deform the film.
- Adhesive Failure: Identifies the threshold where the coating separates from the substrate.
By analyzing the force-displacement graph, engineers derive metrics like critical load (Lc) and scratch hardness, enabling comparative assessments between formulations or processes.
Conclusion
Ideal for R&D and QC labs, the Paint Film Scratch Tester provides actionable insights into coating durability. Its compliance with multiple standards and customizable parameters make it a versatile tool for optimizing material performance in demanding applications.