What is a Coefficient of Friction Tester?
A coefficient of friction (COF) tester is a lab instrument used to measure the static and kinetic friction between two surfaces - commonly a plastic film, sheet, foil, paper, or fabric sliding against itself, another material, or a standardized sled. The result, expressed as a numerical coefficient, indicates how easily one surface slides over another.
Some instruments, like the Labthink C620H, go a step further and combine COF testing with peel strength testing, allowing labs to evaluate adhesive laminates, medical bandages, release liners, and protective films on the same machine.
Why is Coefficient of Friction Testing Important?
Friction directly affects how a material behaves during manufacturing, packaging, handling, and end use. Getting it wrong can be costly:
- Too much friction: causes jamming, tearing, or misfeeds on bag-making and packaging machines
- Too little friction: leads to slippage, poor stacking stability, and product damage during transport
- Inconsistent friction: results in unpredictable machine speeds and increased downtime
- Quality assurance: ensures every batch of film, foil, or laminate performs consistently on the production line
By quantifying friction with a COF tester, manufacturers can fine-tune slip additives, coatings, and surface treatments to hit the exact friction performance their equipment and application demand.
Test Standards for Coefficient of Friction
COF testing is governed by several recognized international and national standards, ensuring results are consistent, repeatable, and comparable across labs and suppliers:
- ISO 8295 - Plastics: Film and sheeting - Determination of coefficients of friction
- ASTM D1894 - Standard Test Method for Static and Kinetic Coefficients of Friction of Plastic Film and Sheeting
- TAPPI T816 - Coefficient of friction (kinetic) of paper and paperboard
- GB 10006 - Chinese national standard for coefficient of friction of plastic film and sheet
- ISO 8510-2 / ASTM D4917 / ASTM D3330 / TAPPI T549 / GB/T 2790, 2791, 2792 - additional peel and friction-related standards (relevant for dual-mode testers like the C620H)
Testing to these standards ensures your data is accepted by customers, auditors, and regulatory bodies worldwide.
Importance of COF Testing in the Packaging Industry
The packaging industry relies on precise friction control more than almost any other sector, because packaging films and laminates move constantly through high-speed automated equipment:
- Form-Fill-Seal (FFS) machines: require consistent film-to-film and film-to-metal friction for smooth feeding and sealing
- Bag-making and pouch-making lines: friction levels affect stacking, opening, and machine runnability
- Palletizing and stacking: correct friction prevents cartons, sacks, and woven bags from sliding during storage and transport
- Laminates and adhesives: peel strength testing ensures medical bandages, protective films, and multi-layer laminates bond and release as intended
- Cold chain and export packaging: friction and adhesion must remain stable across temperature ranges during shipping and storage
For flexible packaging converters, film manufacturers, and laminate producers, COF and peel testing are not optional quality checks - they are essential to avoiding line stoppages, customer complaints, and product recalls.
Recommended Instruments: Labthink C620H & MXD-02
At Flexitest, we supply two proven coefficient of friction testers to match different lab needs and budgets.
Labthink C620H Friction Peel Tester
The C620H is a dual-function instrument offering both COF and peel strength testing in a single machine, with automatic sled lifting, precision temperature control up to 100°C, and a large touch-screen interface. It's ideal for labs handling laminated films, medical adhesives, release liners, and protective films alongside standard friction testing.
- Two test modes: friction and peel
- Force accuracy better than 0.5% FS
- Test temperature: room temp up to 100°C
- Conforms to ISO 8295, ISO 8510-2, ASTM D1894, D4917, D3330, TAPPI T816, T549, GB standards
PARAM® MXD-02 Coefficient of Friction Tester
The MXD-02 is a dedicated, cost-effective COF tester built for high-volume, routine friction testing across films, paper, textiles, rubber, wood, and even specialty materials like hair, grains, and medical tubing. It's a reliable entry point for labs that need accurate, standards-compliant COF data without the added cost of peel or temperature-control functionality.
- Dedicated static and kinetic friction testing
- Accuracy of 0.5% FS
- Adjustable test speed and customizable sled weights
- Conforms to ISO 8295, ASTM D1894, TAPPI T816, GB 10006
Which One Should You Choose?
| Need | Recommended Instrument |
|---|---|
| COF + peel testing in one machine | C620H |
| Testing at elevated temperatures | C620H |
| Budget-friendly, dedicated COF testing | MXD-02 |
| High-volume routine friction checks | MXD-02 |
| Testing laminates, medical adhesives, or films | C620H |
Both instruments are compliant with major international standards and backed by Labthink's precision engineering.
Contact the Flexitest team today to discuss which coefficient of friction tester is right for your lab, or to request a quote for the C620H or MXD-02.
