VMT 414A – Precision Rubbing Fastness Tester

Testing Method

The test involves using a specified felt to apply reciprocating friction on a leather sample under controlled pressure for a set number of cycles. After testing, the degree of color transfer to the felt and any visible damage to the leather surface are compared against a standard gray scale to determine the leather’s grade and durability.

Test Steps

1. Prepare and cut the sample as per the standard requirements.
2. Fix the air-conditioned specimen on the test table and stretch it along the friction direction by 10%. If 10% elongation isn’t possible, stretch the sample to its maximum stable elongation and note this in the test report.
3. For general leather, apply a load ensuring a total test head weight of 1000g. For suede or similar materials, use an unweighted test head with a total weight of 500g.
4. Secure the felt to the test head, ensuring even contact with the leather sample. Set the friction cycle count and start the test.
5. After the test, assess the color change and any damage on both the leather surface and the felt, and record the results.

Ensuring Test Accuracy

1. Ensure the friction head surface is smooth to avoid inconsistent staining.
2. Secure the felt firmly on the friction head to maintain accurate rubbing results.
3. Maintain parallel contact between the friction head and the specimen surface, adjusting grommets if needed.
4. Carefully position the friction head to avoid excessive staining during wet friction tests.

Technical Specifications

• Rubbing Finger Weight: 500 ± 25g
• Additional Loading Weight: 500 ± 10g
• Finger Base Dimensions: 15 x 15 mm
• Specimen Size: 120 x 20 mm
• Rubbing Stroke: 35–40 mm
• Rubbing Speed: 40 ± 2 cycles per minute
• Cycle Counter: 1–999,999 cycles, automatic stop