How are specimens assessed after testing on the Martindale Ball Plate Kit?

The Martindale Ball Plate Kit is used for the abrasion testing of leather.

It is particularly suitable for leather car seats, which are produced to provide a soft yet tough leather surface which must continue through the life of the car.

The tanning process has to soften and strengthen the leather without compromising any of the stringent automotive specifications. During this process, the nature of the animal hide is significantly changed and enhanced, improving its softness, toughness and durability.

The Martindale Ball Plate Kit was developed by the Verband der Automobilindustrie (abbreviated VDA), which  is a German interest group (association) of the German automobile industry, both automobile manufactures and automobile component suppliers. The group, located in Frankfurt, Germany, was set up by the automobile industry itself.

The Martindale Ball Plate complies with:

• VDA Test Method 230-211
• EN ISO 17076-2
• IUP/IULTCS 48-2

All the above methods state that the test should be run initially for 100 rubs and the leather specimens assessed for damages and breaks. This is to confirm the accuracy of the apparatus. The number of damages or breaks should be reported. The test should then be continued and the specimens checked at intervals until 4 damages or breaks can be seen. It is acceptable to use a magnifier or microscope to assist in the assessment.

A damage or break is defined as when the outer finish layer is completely damaged leading to breaks or damages in the now visible leather fibres. 

There are no standard photographs as you would expect for a piling or snagging test, and no grades or levels of deterioration. The test is run until 4 damages are reported, not run to a set point and then assessed as is the way with pilling and snagging.