Protective Film Hardness Testing Procedure

1Preparing for the Test

• Select a flat, wrinkle-free protective film sample.
• Ensure the test area is clean and free of dust, oil, or scratches to prevent impurities from affecting the test results.
• Secure the protective film flatly on a hard surface.
• Use tape to gently secure the edges to prevent the film from shifting during testing.
• Gather the necessary testing tools and cleaning supplies, ensuring the tool surfaces are clean and free of sharp objects.

2Choosing the Appropriate Testing Tool

• Select the appropriate hardness testing tool based on the characteristics of the protective film, such as a pencil hardness tester or a Shore durometer.
• A pencil hardness tester is used to assess a surface's scratch resistance and requires standard test pencils of varying hardness grades.
• A Shore durometer measures the overall hardness of a material.
• Ensure the instrument is calibrated and the test tip is clean and free of wear.

3Standardizing the Testing Procedure

• When using a pencil hardness tester, hold the pencil at a 45-degree angle to the surface of the protective film.
• Gently and evenly stroke the test area in a straight line, avoiding excessive force or excessive speed that may cause damage.
• When using a Shore hardness tester, press the test tip vertically against the protective film surface, maintaining steady pressure until the reading stabilizes.
• Avoid shaking or tilting the instrument during testing.
• Repeat the test at different locations on each test area to ensure representative results.

4Observe and Record Test Results

• After the test, carefully observe changes to the protective film surface.
• If using a pencil tester, inspect for obvious scratches or damage, and record the highest pencil hardness rating without damage.
• If using a Shore hardness tester, record the stable reading displayed on the instrument and observe any dents or deformation at the test point.
• Any abnormalities during the test, such as cracking or shedding of the film, should be recorded in detail.

5Comprehensive Hardness Performance Evaluation

• Combining multiple test results, analyze the results, eliminate abnormal data, and determine the hardness range of the protective film.
• Compare the test results to the product standard or usage requirements to assess whether the protective film's scratch resistance and overall hardness meet the standards.
• If the test results do not meet the requirements, verify the test method or the sample quality.
• If necessary, replace the sample and retest to ensure accurate and reliable evaluation results.