Dynamic Coefficient of Friction (DCOF) Analysis

Dynamic coefficient of friction (DCOF) is an industry standard for measuring the slip resistance of a surface and is rapidly replacing static coefficient of friction (COF) tests.

The coefficient of friction can be two different things: the coefficient of static friction or the coefficient of dynamic friction. The coefficient of static friction is the friction force between two objects when neither object is moving. The coefficient of dynamic friction is the force between two objects when one object is moving or when two objects are moving against each other. The coefficient of friction is dimensionless and has no units. The direction of the force does not affect the physical quantity.

The coefficient of friction depends on the objects causing the friction. The value is usually between 0 and 1, but can be greater than 1. A value of 0 means there is no friction between the objects. A value of 1 means the friction force is equal to the normal force. It is a misconception that the coefficient of friction is limited to values ​​between zero and one. A coefficient of friction greater than one means that the friction force is stronger than the normal force. For example, an object such as silicone rubber can have a coefficient of friction much greater than one. The friction force is the force exerted by a surface when an object moves over it or makes an effort to move over it.

Dynamic coefficient of friction (DCOF) is the primary product performance measure used by the tile industry to determine suitable applications for a flooring product. When it comes to choosing the right tile for an area, DCOF is a key consideration, especially when selecting tiles for areas that may be exposed to water, oil or grease.

The standard “ANSI A326.3 Dynamic coefficient of friction (DCOF) of hard surface flooring materials” developed by the American National Standards Institute (ANSI) describes a test method for determining the dynamic coefficient of friction of hard surface flooring materials. This standard also provides DCOF standards, product use classifications, and guidance for specifying hard surface flooring materials. The ANSI A326.1 standard requires tile flooring products to have a DCOF value of 0,42 or greater if they are intended for use on a flat interior surface intended to be walked on when wet. This specification is based on a wet DCOF measurement performed in accordance with the ANSI A326.3 standard.

The ANSI A326.3 standard measurements are based on specific standard practices under controlled conditions. These measurements provide useful information for comparing product performance, but the measurements should not be considered an indication of whether slipping will occur. Friction is the inherent force that resists the sliding motion of one surface against another. The DCOF of a surface is a measure of the force required to cause a surface already in motion to slide over another surface and is analogous to the frictional forces experienced by a person walking.

This method is the most widely accepted measurement of the dynamic coefficient of friction (DCOF) for hard surface flooring, not just ceramic tiles.

In general, the recommended product application is detailed based on the measured DCOF values. Due to the limitations of the test, the measured DCOF value is not a suitable indicator of performance for all product types. Details are as follows:

• Dry and level indoor: Level public areas that are dry and free of contaminants. For example, but not limited to hotel lobbies, apartment buildings, public buildings, shopping malls (excluding food courts), hospitals, elevator lobbies, interior corridors, cafeterias, retail stores, theater lobbies, and other dry healthcare areas. DCOF value of at least 326.3 dry per ANSI A0,42 standard.
• Wet and level interior: Level public areas that are likely to be walked on when wet. For example, but not limited to, entrance foyers of hotels, offices, and other public buildings, supermarkets (entry areas, food preparation, any area where produce or water may occasionally be present), shopping mall food courts and restroom facilities, and manufacturing areas that do not contain oil or fat. A DCOF value of at least 326.3 wet per ANSI A0,42.
• Outdoor applications: Pedestrian areas that may be exposed to water (except ice) but are reasonably maintained and where footwear is commonly used. For example, but not limited to, walkways, pergolas, or patio areas. DCOF value of at least 326.3 wet per ANSI A0,60.
• Pool deck (and other wet areas with minimal footwear): Recreational areas with continuous water, with light or no footwear. For example, but not limited to: public showers, steam rooms, swimming pool decks and locker rooms. DCOF value of at least 326.3 wet according to ANSI A0,60 standard.
• Oils (fats/greases): Production areas containing oil, grease or fat. For example, but not limited to automotive fluids, cooking areas, areas containing frying and grilling equipment, other food preparation areas containing grease or oil. DCOF value of at least 326.3 wet per ANSI A0,60 standard.
• Ramps and slopes: Sloping areas or ramps. For example, but not limited to stairs and stair nosings, wheelchair ramps, workshop bays (where no oil is present), sidewalks and driveways where pedestrian traffic is normally present. DCOF value of at least 326.3 wet per ANSI A0,65.

The ANSI A326.3 standard essentially identifies materials that are suitable for specific project conditions. These conditions depend on the type of use, traffic, expected contaminants, expected maintenance practices, expected wear, and the manufacturer's recommendations. Dynamic coefficient of friction analysis data is needed to evaluate whether a surface is suitable for a particular application.

Among the numerous testing, measurement, analysis and evaluation studies that our organization has carried out for businesses in various sectors, it also provides dynamic coefficient of friction (DCOF) analysis services with its trained and expert staff and advanced technological equipment.