ISO 21182 - Conveyor Belt Friction Coefficient Testing Method

Light conveyor belts — Determination of the coefficient of friction

In industries where conveyor belts play a pivotal role—such as packaging, pharmaceuticals, food, and logistics—ensuring operational efficiency requires detailed attention to frictional characteristics. ISO 21182 offers a standardized method for measuring the coefficient of friction in light conveyor belts. This article provides a comprehensive overview of ISO 21182, explains how to perform the test, and discusses how quality professionals can apply these insights to optimize production and reduce machine wear.

Why ISO 21182 Matters

ISO 21182 sets the global benchmark for determining the dynamic and static friction coefficients of light conveyor belts. Proper assessment of these frictional properties ensures smooth operation, prevents slippage or jamming, and extends equipment life.

The test is crucial for:

Material manufacturers assessing product consistency
OEMs validating design parameters
End-users troubleshooting or improving system performance

Conveyor Belt Friction Coefficient and Its Importance

The conveyor belt friction coefficient describes how much resistance a conveyor belt surface provides against movement. It is generally categorized as:

Static coefficient of friction (μS): The resistance to start movement
Dynamic coefficient of friction (μD): The resistance during movement

For instance, a higher μS may prevent slippage when the belt is stationary but can increase wear. A lower μD may enhance energy efficiency but risk loss of grip.

ISO 21182 helps balance these trade-offs by standardizing how both coefficients are measured, ensuring consistency across materials and systems.

Test Principles Based on ISO 21182

The test involves pulling a metallic test panel across a sample of the conveyor belt material under controlled conditions. Two types of tests are performed:

1. Dynamic Test (μD):

A test panel is dragged across the clamped belt surface at a speed of 1000 ± 20 mm/min.
The average force during motion is recorded and divided by the normal force to calculate μD.

2. Static Test (μS):

The test panel is pulled at 100 ± 20 mm/min until motion begins.
The peak force before motion is used to calculate μS.

The equipment setup includes a horizontal test table, load cell, pulling mechanism, and standard steel test panel, all conforming to detailed specifications in ISO 21182.

Test Conditions and Specimens

To ensure reliability:

Test specimens should be cut from unused belt material and conditioned for at least 24 hours under ISO 18573 Atmosphere B.
Three samples are required for each surface direction (longitudinal and transverse).
Each piece should measure 600 mm × 100 mm.
Testing should occur at standard room conditions (temperature and humidity) to maintain consistency.

Calculation and Interpretation of Results

μD = FD / FN (dynamic friction force divided by normal force)
μS = FS / FN (static break-away force divided by normal force)

Force-path graphs help visualize these values. A sharp peak indicates μS, while a smooth curve denotes μD.

Understanding these results helps technicians select the right materials for high-speed packaging lines or inclined transport systems.

COF-01 Coefficient of Friction Tester

For companies seeking precise, ISO 21182-compliant measurements, we recommend the COF‑01 Coefficient of Friction Tester by Coefficientfriction.com.

Key advantages include:

High accuracy load cell for static and dynamic measurements
Compatibility with multiple materials, from plastic films and papers to specialized conveyor surfaces
Compliance with ISO 21182, ASTM D1894, TAPPI T816, and other international standards

Whether you’re testing a polyethylene belt or a laminated composite, the COF‑01 offers repeatable, user-friendly testing for both static and dynamic COF.