Traction Coatings and Friction Modifiers Information
Figure 1: Non-slip surface. Source: Hunini/CC BY-SA 4.0
When surfaces need better traction or higher friction, special coatings and modifiers are used to modify the problem surface. By increasing the coefficient of friction of a surface, slippage is less likely. By increasing the lubricity of machine components, downtime is reduced and machines become more energy efficient. Traction coatings and friction modifiers make surfaces safer, longer lasting, and more efficient.
Theory of Operation
Traction coatings and friction modifiers both work by modifying a surface’s coefficient of friction. Whether to reduce the slipperiness of a floor or to reduce wear in machinery components, the theory of operation is very similar.
Adhesion is the process by which two surfaces come into contact and adhere to one another When a traction coating or friction modifier is applied to a surface, it creates a thin layer of material that is designed to improve the coefficient of friction or the amount of traction that can be achieved on that surface.
Friction modifiers are commonly added to lubricants to change the coefficient of friction of the surfaces in contact. These components must be properly lubricated so that they do not seize up but must also have a high enough coefficient of friction that slipping does not occur.
Figure 2: The friction modifiers in lubrication adhere to metal surfaces and provide enhanced performance. Source: Pixabay
Friction modifiers can be inorganic or organic compounds that can be added to the lubricant to reduce wear and increase lubricity, improving energy efficiency and longevity. The friction modifiers in lubrication adhere to metal surfaces and provide enhanced performance. These compounds are usually added in small amounts, typically less than 1% of the total volume, as they can change the viscosity and other properties of the lubricant.
Traction coatings are typically applied to surfaces in order to improve the amount of traction that can be achieved on that surface. Many smooth surfaces provide little traction and, when lubricated with something like water or oil, can become dangerous. Traction coatings work by adding a rough or textured surface to the coating, which can increase the coefficient of friction between the surface and any object that comes into contact with the surface. These coatings can be applied to a variety of surfaces, including metals, plastics, and ceramics, and can be used in a variety of applications.
Specifications
When comparing traction coatings and friction modifiers, pay attention to key specifications.
Roughness Average
This parameter gives an idea of how rough the surface will be. Measured in micrometers and micro-inches, the larger the number, the rougher the surface will be.
Hardness
Some traction coatings are softer and provide a different feel than hard traction coatings. The hardness number will typically be a number on the Rockwell scale. High RC values will be harder than lower values.
Bond Strength
A direct reflection of the product’s durability, bond strength will typically be listed as a psi value. Traction coatings should be able to withstand the wear and tear of regular use. They should be able to maintain their level of performance over time, and should not degrade or wear away easily. For more intense applications, higher bond strength is critical.
Electrical Conductivity
Ensuring proper electrical conductivity prevents the dangerous build-up of charges. Check whether the traction coating being used is electrically conductive and whether or not that is correct for the application.
Temperature and Chemical Resistance
Traction coatings and friction modifiers should be able to resist the effects of high temperatures, chemicals and other environmental factors. If used in harsh conditions, it is imperative that a traction coating that can withstand those conditions is chosen.
Viscosity
Friction modifiers should have the right viscosity to ensure it can be mixed well with lubricants. Friction modifiers should enhance the overall performance of the lubricant and not degrade performance.
Service Life
Various types of traction coatings and friction modifiers will have different expected service lives. Ensure that the product chosen will have a service life that meets or exceeds the expectations for the application.
Types
There are several types of traction coatings and friction modifiers, including:
Abrasive Coatings
These coatings use abrasive materials, such as silica or aluminum oxide, to create a rough or textured surface that increases traction. They are commonly used on metal surfaces such as stairs, walkways, and machinery. These materials can often be mixed into solutions like paint to enhance the traction of a given coating.
Polymer Coatings
These coatings use a variety of polymeric materials, such as polyurethane or epoxy, to create a durable and slip-resistant surface. They are commonly used in industrial and commercial settings to improve traction on floors and walkways.
Metal-based Coatings
These coatings use metal particles, such as aluminum or steel, to create a rough or textured surface that increases traction. They are commonly used on metal surfaces such as machinery and equipment.
Organic Friction Modifiers
These are typically organic compounds, such as fatty acids or esters, that are added to lubricants to reduce friction and wear. They are commonly used in automotive and industrial applications to improve energy efficiency.
Inorganic Friction Modifiers
These are typically inorganic compounds, such as metallic soaps, that are added to lubricants to reduce friction and wear. They are commonly used in high-temperature applications, such as in high-performance engine oil.
Figure 3: Motor oil. Source: SIGAUS/CC BY-SA 4.0
Dry Lubricant Coatings
These coatings use a dry lubricant such as molybdenum disulfide, graphite, or tungsten disulfide to reduce friction between surfaces. They are commonly used in high-temperature or high-pressure applications where traditional lubricants may not work.
Nanoparticle Coatings
These coatings use nanoparticles, such as carbon nanotubes or graphene, to create a smooth and slippery surface that reduces friction. They are commonly used in advanced industrial and electronic applications.
These are some of the most common types of traction coatings and friction modifiers. Each type has its own unique properties and characteristics, and is best suited for specific applications and use cases.
Features
Traction coatings and friction modifiers have several features that make them useful in a wide range of applications. Some of these features include:
Increased Traction
One of the main features of traction coatings is that they of course increase the amount of traction that can be achieved on a surface. This can be done by adding a rough or textured surface to the coating, which can increase the coefficient of friction between the surface and the object that is in contact with it.
Reduced Noise
Machine components are typically quieter when friction modifiers are used appropriately. The quieter operation comes from the improved traction and decreased wear of the components in the machine.
Durability
Traction coatings and friction modifiers are designed to be durable and withstand regular use. They should be able to maintain their level of performance over time, and should not degrade or wear away easily. Traction coatings should also not chip away.
Easy Application
While friction modifiers can often be easily mixed into a solution, traction coatings can sometimes be a bit more difficult. Look for traction coatings that are easy to apply, and that don’t require special equipment or training to use. They should be able to be applied quickly and efficiently.
These are some of the most important features of traction coatings and friction modifiers, but there may be other factors to consider depending on the specific application and use case.
Manufacture
In general, the manufacturing process of traction coatings and friction modifiers involves the mixing of raw materials, application of the mixture on the surface, and curing or drying of the mixture. Before applying a traction coating several steps including cleaning, priming, and quality control checks are required. Traction coatings must be able to properly adhere to the substrate. The final product must meet the specifications and features required for the specific application.
Friction modifiers can be added directly to a solution but it is imperative to check that the friction modifiers will stay in suspension and will not negatively affect the performance of the solution. If the friction modifiers separate out from the solution, they will lose their benefits and may even negatively affect the system.
Applications
Traction coatings and friction modifiers have a wide range of applications in various industries. Some of the most common applications include:
Automotive
Traction coatings and friction modifiers are commonly used in the automotive industry to improve the traction and performance of tires and other vehicle components. They can also be used to improve the efficiency and performance of engines and other mechanical systems.
Friction modifiers in automotive lubricants are also critical for longevity and fuel efficiency. Reduced wear on components allows for longer lubricant and component life. Reduced slipping of components also keeps energy moving to the desired location and not being wasted.
Industrial
Traction coatings and friction modifiers are commonly used in industrial settings to improve the traction and safety of floors, walkways, and other surfaces. They can also be used to improve the performance of machinery and equipment, and to reduce wear and tear on these components.
Friction modifiers show up in many machines as well. Whether to improve the performance of gripper jaws and rolling machines or to increase the lubricity of internal components, friction modifiers are there.
Sports Equipment
Traction coatings are commonly used on sports equipment such as skis, snowboards, and skateboards to improve their grip and performance. Without these traction coatings, these pieces of equipment would be much harder to use.
Marine
Traction coatings and friction modifiers are used on boats and ships to improve the performance of the hull and propellers, and to reduce drag and fuel consumption. Additionally, traction coatings keep walkways safe on maritime vessels. Even with liquid water present, properly applied traction coatings can provide enough friction for people to walk on without slipping.
Construction
Traction coatings are used on construction equipment and heavy machinery to improve the grip and performance of the equipment. Safety is key and by adding traction coating to key locations, accidents are prevented.
Energy
Traction coatings and friction modifiers are used in the energy industry to improve the performance of wind turbines, hydroelectric generators, and other energy-producing equipment. Friction modifiers were even first added to engine oil lubricants in the 1980s to increase the fuel efficiency of vehicles during the oil shortage.
Medical
Traction coatings and friction modifiers are used in the medical industry to improve the performance of prosthetic devices and to reduce the risk of slips and falls in hospitals and other healthcare facilities.
These are just a few examples of the wide range of applications for traction coatings and friction modifiers. These materials can be used in many other industries and settings where improved traction, durability, and performance are needed.
Standards
There are several standards that apply to traction coatings and friction modifiers. These standards help ensure that these materials meet certain performance, safety, and quality requirements, and are consistent across different manufacturers and applications. Some of the most common standards include:
- American Society for Testing and Materials (ASTM International)
- International Organization for Standardization (ISO)
- Underwriters Laboratories (UL)
- Society of Automotive Engineers (SAE)
- Occupational Safety and Health Administration (OSHA)
ASTM International is a global organization that develops and publishes technical standards for a wide range of industries. They have standards for traction coatings and friction modifiers, such as ASTM D2047, which covers the slip-resistance of pedestrian surfaces, and ASTM D1894, which covers the static coefficient of friction of plastic film and sheeting.
ISO is a global organization that develops and publishes international standards for a wide range of industries. They have standards for traction coatings and friction modifiers, such as ISO 8295, which covers the determination of the static coefficient of friction of flooring surfaces.
UL is an independent safety science company that conducts safety testing and certifies products. They have standards for traction coatings and friction modifiers, such as UL 410, which covers the slip resistance of floor coverings.
SAE is a professional organization that develops standards and recommended practices for the automotive industry. They have standards for friction modifiers, such as SAE J306, which covers the performance requirements of friction modifiers.
OSHA is a federal agency that sets and enforces safety standards in the workplace. They have standards for slip, trip, and fall hazards, such as 29 CFR 1910.22, which covers walking and working surfaces, including slip resistance.
These are just a few examples of the standards that apply to traction coatings and friction modifiers. It is important to check the specific standards that apply to the industry, application or use case, as these standards may vary depending on the product and application.