Difference between static friction coefficient and dynamic friction coefficient

Coefficient of friction testing is a test that helps measure the ability of plastic films to stack. It helps prevent accidents that usually occur due to friction in packaging, shipping, loading, materials, etc. Friction may vary due to uneven film thickness, which may also result in uneven film strength. The COF of plastic films can be easily tested with the help of a testing machine , the coefficient of friction Tester. It is widely used to verify foil, paper, plastic film and other related materials. In order to find dynamic and static friction, users can also adjust the speed of the package by testing the coefficient of friction.

The coefficient of friction, also known as COF, can be easily assessed by providing or sliding a facade of two materials. The dimensional value for the coefficient of friction is actually measured as the ratio of the force required to slide a material facade to the force perpendicular to the surface. A lower coefficient of friction indicates a smoother surface, meaning the material is less resistant to sliding motion. The coefficient of friction value is directly related to the slip properties of the film.

Difference Between Static Friction and Kinetic Friction Compare the Difference Between Similar Terms

The difference between the two friction types is known as the "slider". Static COF is measured at the point of incipient movement, whereas dynamic COP is measured at a constant velocity.

The coefficient of static friction is represented by (μ0)

It is defined as the coefficient of friction for the instantaneous motion between the starting faces

Kinetic friction coefficient by (μs)

It is defined as the coefficient of friction that establishes motion between surfaces.

How to calculate the coefficient of static friction?

The static coefficient of friction is calculated by the given formula.

 fs=μs*N

The coefficient of friction can be tested according to the test requirements and sample type. The instrument can perform 3 types of tests.

1. Sample to Sample

2. Sample to Glass

3. Sample to metal

How to use COF Tester for testing?

COF testing can only be easily performed by sliding a flat surface under its own weight. The instrument is designed according to various standard test methods provided by different standardization bodies such as ASTM D1894, ASTM D202, ASTM D4918, ISO 8295 and TAPPI T815. According to the standard, the film sample is firmly attached to the bottom of the block. The block is connected to a load cell, which helps measure the friction between the block and the flat surface.