Coefficient of Friction (COF)

The coefficient of friction is a dimensionless variable that is useful in characterizing a material’s frictional properties. COF measurement is frequently performed for plastic films, sheeting, lubricants, paper, etc.

Talk to an Expert

TRUSTED BY

Precision-driven testing for dimensional accuracy and compliance

Overview
Scope, Applications, and Benefits
Test Process
Specifications
Instrumentation
Results and Deliverables

Overview

ASTM D1894 is a standardised test method used for finding the static and kinetic coefficient of friction (COF) of plastic films and sheeting in contact with themselves or other surfaces.

This method is important for testing the frictional properties of materials, as it has a direct bearing on the handling, processing, and end-use properties of materials. The static coefficient of friction is the amount of force required for motion, while the kinetic coefficient of friction is the amount of force required for continued motion between two surfaces.

Scope, Applications, and Benefits

Scope

ASTM D1894 is the standard that dictates how we go about determining friction properties for plastic films, sheets, and other flexible plastic materials. The test essentially replicates real-world applications by determining how smoothly one object slides across another under specific circumstances. This is an essential test for packaging, converting, and plastics manufacturing industries to ensure that materials are functioning as expected.

The key parameters of interest were:

– Static coefficient of friction (COF)
– Kinetic coefficient of friction (COF)

Applications

Packaging films and laminates
Flexible packaging materials
Plastic bags and pouches
Medical and pharmaceutical packaging
Food packaging films
Printing and labelling industries
Automotive interior films
Quality control in film manufacturing
Research and development of low-friction materials

Benefits

Ensures smooth material handling and processing
Reduces issues in packaging machinery
Improves product performance and usability
Controls surface properties of films
Supports material selection and design
Enhances consistency in manufacturing
Provides standardised friction measurement
Helps prevent sticking or slipping issues

Test Process

Sample Preparation & Setup

Film samples are cut, conditioned, placed on a test platform, and a standard sled is positioned on top.

Static Friction Measurement

The force required to initiate movement of the sled is measured.

Kinetic Friction Measurement

The force required to maintain uniform sliding motion is recorded.

Calculation & Reporting

Coefficient of friction (COF) is calculated from force data and reported.

Technical Specifications

Parameter	Details
Applicable Materials	Plastic films and sheeting
Measured Parameters	Static COF and Kinetic COF
Test Conditions	Controlled temperature, humidity, and sliding speed
Sled Weight	Typically 200 ± 2 g (standard, may vary)
Output Units	Coefficient of Friction (dimensionless)

Instrumentation Used for Testing

Coefficient of friction tester (COF tester)
Motorised horizontal test platform
Standard sledge with specified weight
Load cell for force measurement
Sample cutting tools
Conditioning chamber
Data acquisition and analysis software

Results and Deliverables

Static coefficient of friction values
Kinetic coefficient of friction values
Friction behaviour analysis
Material performance evaluation
Comparative analysis reports
Reports

Why Choose Infinita Lab for Coefficient of Friction (COF)?

Infinita Lab is a trusted USA-based testing laboratory offering Coefficient of Friction (COF) testing services across an extensive network of accredited facilities across the USA.

Infinita Lab is built to serve the full spectrum of modern testing needs—across industries, materials, and methodologies. Our advanced equipment and expert professionals deliver highly accurate and prompt test results, helping businesses achieve quality compliance and product reliability.

Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you. Request a Quote

Frequently Asked Questions

The coefficient of friction (μ) is a dimensionless quantity that represents the ratio of the force of friction between two bodies to the normal force pressing them together.

There are two types of COF: Static and Kinetic (dynamic) COF.

The factors affecting COF are: Material properties, environmental conditions, and contact conditions.

The standards test methods used in calculating COF are: ASTM D1894 & ASTM C1028.

Static COF is the force required to initiate movement between two surfaces at rest, while kinetic COF is the force required to maintain movement once sliding has started.