Coefficient of Friction Test

Testing the physical properties of materials is crucial across various industries, from packaging and food to medicine and academia. One essential measurement in this realm is the friction coefficient, a key factor influencing material slipperiness.

Test Application of Coefficient of Friction Tester

The coefficient of friction meter is used to measure the coefficient of static friction and coefficient of dynamic friction when materials such as plastic films and sheets, paper, etc. slide. By measuring the slipperiness of the material, it is possible to control and adjust the production quality process indicators of the material to meet the product use requirements. The coefficient of friction meter can also be used to measure the static friction coefficient of rubber, cardboard, woven bags, fabric styles, metal material composite belts for communication cables, conveyor belts, wood, coatings, brake pads, wipers, shoe materials, tires and other materials when sliding and coefficient of kinetic friction.

Coefficient of Friction Test Principles

In line with the ISO 8295 and ASTM D1894, the test principle involves bringing two surfaces into contact, applying a specific pressure, and inducing relative motion. The resulting force is recorded and used to calculate the friction coefficient, expressed as the ratio of the tested force value to the gravity of the slider.

Coefficient of Friction Test Terms and Definitions

• Friction: The hindrance to the sliding of two contacting surfaces, categorized into kinetic and static friction.
• Static Friction: The critical friction that must be overcome when sliding begins.
• Dynamic Friction: Friction existing during sliding at a given velocity.
• Frictional Force: Force required to overcome friction, divided into static and dynamic friction forces.
• Normal Force: Force applied perpendicularly to two contact surfaces.
• Friction Coefficient: The ratio of friction to normal force, comprising static and dynamic coefficients.

Coefficient of Friction Testing Equipment Requirements

1. The surface of the horizontal test bench should be smooth and made of non-magnetic metal material.
2. The normal force is generated by the slider. The slider should have a square bottom surface with an area of 40cm² (side length 63mm). In order to make the pressure evenly distributed, the bottom of the slider should be covered with elastic materials such as felt. The elastic material must not cause “embossing” of the sample . The total mass of the slider should be 200g ± 2g to produce a normal force of 1.96N ± 0.2N.
3. The driving structure should have no vibration so that the two test surfaces move relatively at a speed of 100mm/min±10mm/min. When there are special needs, the speed can be set to 500mm/min±10mm/min.
4. The total error of the entire force measuring system including the recorder should not exceed 2%, the conversion time should not exceed 0.5s, and the traction direction should be kept parallel to the friction plane and on a straight line.
5. For the measurement of static friction, the elastic coefficient of the force measuring system should be adjusted to 2N/cm ± 1N/cm by an appropriate spring. When measuring kinetic friction in the slip-stick situation, the spring is replaced by a rigid connection.