VMT 412 – Rotary Vertical Crockmeter

Testing Method

Purpose and Scope

This method assesses the degree of color transfer from the surface of colored textiles to other materials due to friction. It is suitable for colored yarns and fabrics of various fibers, including dyed, printed, and other colored textiles. This method is especially effective for testing printed textiles with small areas that standard methods cannot accommodate.

Test Principle

The specimen is fixed on the base of the rotating vertical friction instrument and rubbed with standard friction cloth under specified conditions. The degree of color transfer to the friction cloth is evaluated by comparing it against a stained gray card or an AATCC color card.

Sample Preparation

The specimen should be tailored to a specified area and conditioned before testing. Both the sample and the friction cloth should remain under atmospheric conditions of 21°C ± 1°C and relative humidity of 65% ± 2% for at least four hours.

Dry Friction Test Procedure

1. Attach the standard friction cloth to the end of the vertical rod and secure it with the spring clip.
2. Fix the specimen on the instrument base so the friction cloth makes direct contact with the sample.
3. Apply downward pressure on the friction head with the instrument’s weight.
4. Hold the specimen steady and rotate the crank to initiate the rubbing motion.
5. After the specified number of rotations, remove the sample and friction cloth and evaluate the degree of color transfer.

Operational Notice

• Ensure the friction head surface remains even; an uneven stained pattern suggests it may need resurfacing.
• Elongated ghost patterns may indicate a loose spiral metal clip.
• Marks on the specimen’s edge suggest incorrect positioning of the spiral metal clip.
• Replace friction sandpaper if the friction area becomes smooth or if the sample slides during testing.