What is coatings?
Coatings, otherwise known as layers on the surface of a substrate, serve many different purposes, whether decorative, functional, or some combination of both. They can be in liquid, gas, or solid form, like powder coatings.
From a surface engineering perspective, coatings are a layer of material that is deposited onto a substrate to improve surface performance through corrosion resistance or wear protection.
The decision-making process for which coatings to employ is influenced by the environment of use, how long the coating will be expected to last, compatibility with the substrate material, shape and size of the component to be coated, and of course, cost.
More specifically, coatings provide an essential function in the realm of surface engineering because they serve to protect against the effects of corrosion and wear.
Coatings come in many different varieties, each serving an entirely different purpose, or potentially purposes. We typically think of coatings as being liquid, gas, or solid; one type of solid coating is powder coatings.
Many factors are considered when determining coatings, such as environment of use, expected length of protection, compatibility with substrate materials, and reasonably its overall cost.
Coatings are not simply coatings; they are silent protectors of the performance and life of many surfaces. There are a variety of processes for coatings to deposit materials of all sorts and thicknesses, from as little as a few microns, to millimetres.
Many processes can be organized into classifications, and often they are classified in terms of how the coating has deposited material onto the substrate surface.
Examples of coating deposition types. Common examples in the table below of types of coating deposition.
Coating Deposition Type
| Atomic deposition | Particle deposition | Overall coating or cladding | Surface modification |
| Electrolytic deposition | Spray/Brush | Painting and Dip Coating | Anodizing |
| Physical Vapor Deposition (PVD) | Impact plating | Laser cladding | Electrolytic conversion |
| Plasma deposition | Enamel | Overlay welding layer | / |
| Chemical Vapor Deposition (CVD) | Electrophoretic | Roll bonding | / |
The world of coatings is a strange, and complex, but exciting world. It involves the strategical use of materials applied to surfaces, with multiple options, to provide a myriad of protective, decorative and functional features and applications.
Coatings are not simply coatings; they are protectors of a surface helping to provide durability, durability, aesthetics and protection from the environment.
What Are Coatings Made With?
Coatings are a straightforward subject that are complex: they involve complicated formulation.
The vast majority of surface coatings used in industry, and by consumers, are of synthetic polymers, which means they are produced substances, of which are composed of extremely large quantities of molecules that are uniquely tied together, which form tough, flexible, adhesive films when applied to surfaces.
The makeup of coatings depends on the functionality, and aesthetics needed such as colour and gloss. In general, the components of coatings are the follow four components; film forming substances, pigments, solvents, and additives.
Film forming substances:
The “Film” of Coatings. Film forming substances are the building blocks of the coating film, vary from oils, processed oils, cellulose, natural resins, synthetic resins, and synthetic emulsions.
This section is about partially volatile active diluents. Active diluents will give excellent film to substate adhesion so the coating film will coalesce to a continuous film.
Once you determine the type of film-forming substances (epoxies, rubbers, polyurethanes, silicones, acrylics, resins, phenolics, fluorocarbons, nitro, alcohols, fats, amines and fluorinated) that you are going to use, you have already established many characteristics of the final film.
Adaptation with Additives:
An important aspect in coating formulations are additives (or auxilliaries). Additives are defoamers, levelling, thickeners, rheology, special additives, and diluents.
Additives do not make the film, but as the name implies, because of the small amount of additive materials utilized, exhibits an important impact on the coating process and durability. Special functional additives, such as substrate wetting agents, are specific performance additives.
Pigments:
Imparts Colour and relatively solid Mass. Pigments are subdivided into two general categories; pigments that provide colour and pigments that provide body.
Pigments not only provide colour in coatings but certain properties are imparted to the coating. Pigments that provide colour are predominantly titanium dioxide or chrome yellow. Body pigments consist of calcium carbonate or talc (i.e. fillers).
Solvents:
achieving consistency. The function of solvents; hydrocarbons (mineral spirits, kerosene, gasoline, benzene, toluene, xylene), alcohols, ethers, ketones, and esters, will disperse the other film-forming bases into a viscous liquid by removing the liquid coating the solvent created the required viscosity of the coating material for application plus enhancing some features of the coatings.
Solvent compatibility should consider the film-forming base and the method of application to apply the coatings.
In short, coatings are comprised of different parts that function together and apart to achieve a final product.
A comprehensive understanding of the total makeup of a coating (the film-forming substances, for example, the auxiliary agents, pigments, and solvents) assists in exploring the magic of coatings as a process.
Tightly controlled combinations of elements constrain the look of the coating while also constraining the way the coating performs in a variety of applications.
From protection to aesthetic to functional, coatings illustrate the best of both worlds when it comes to art, and science conversion of materials. Because of that, coatings have a lot of unique classification systems. Let’s look at the common classifications of coatings.
What are the classifications of coatings?
Let’s explore the classifications of coatings. As people on a colorful journey through coatings, let’s dive into the answers to “What are the classifications of coatings?”
Coating Status:
There are coatings in a variety of types that will have a different chemical and physical properties and functions for their applications.
- Solvent based coatings – typical, versatile usage
- Water based coatings (emulsion and waterborne)- environmentally friendly and easy to use
- Powder coatings- the dry form creates a hard finish
- High solids coatings- very high performance and lower environmental impact
- Sol-gel coatings- another option and method to create thin films
- Artistic coatings – powder, gloss, matte and all types of color.
Coatings by usage:
Coatings will be used for different ends based on application and will be classified based on their role in four main uses.
- Industrial Coatings: Plastic coatings, coil coatings, paper coatings, ship coatings, automotive coatings, leather coatings, bridge coatings, aircraft coatings, wind power coatings, nuclear power coatings, can coatings, home appliance coatings, pipeline coatings, steel structure coatings and other forms of industrial coatings.
- Architectural Coatings: Like interior wall paint, exterior wall paint, latex paint, metal paint, floor paint, cement paint, asphalt paint, etc.
- Decorative Coatings: You’ll see decorative coverings in products which can alter how you perceive a surface, such as wood coatings, metallic, color and clear coats. Within each decorative effect we can divide them into flat coatings with flat but smooth surfaces (otherwise known as flat coatings) which is the most common construction method; sand wall-like paint with a sand-like decorative effect, like real stone paint; multi-layer paint with an aesthetically three-dimensional decorative effect of concave and convex patterns, like relief.
- Maintenance Coatings: Defined as they relate to the function of its coating, i.e. waterproof, fireproof, heat resistant, etc… Below are more detail paint function types and their uses.
Coating Performance & Function:
Examining the various ways we classify coatings by their performance and function provides an immense number of choices related to their particular needs.
- Teflon coatings: Non-stick properties.
- Waterproof coatings: Protects from water damage.
- Non-stick (anti-pollution) coatings: Dirt and contaminants.
- Fire-resistant coatings: Slows spread of flame.
- Heat-resistant coatings: Survives high heat.
- Conductivity coatings: Electrically conductive.
- Temperature-indicating coatings: Color changes with temperature.
- Rust-resistance coatings: Corniforms from corrosion.
- Anticorrosive coatings: Enhances resistance from corrosion.
- Anti-aging coatings: resists aging.
- Acid-base resistant coatings: Protects against chemical reactions.
- Insulating coatings: Electrically insulating.
Construction Method:
The way coatings are applied also plays a large part in how we classify them.
- Spray coatings: Gives you a uniform and consistent coverage very efficiently.
- Brush applied coatings: Allows for more precision and control.
- Roller coatings: Provides an even application.
- Dip coatings: Dipping things in a solution for total coverage.
- Electrophoretic Coatings: Coating process by electrical current.
Film-forming substances:
Coating film-formers may be classified as organic coatings and inorganic coatings based on their base materials. This means that there are thin films made from different physical materials and these, in turn, directly contribute to the properties and performance of the coating.
Organic coatings generally contain organic binders. Due to the different solvents used, organic coatings can be put into two categories: organic solvent-based coatings and organic water-based (water-emulsion, water soluble) coatings. Most coatings we see in our daily lives are organic coatings.
Inorganic coatings are coatings made with inorganic polymers or inorganic polymer materials as all or most of the base materials. Inorganic coatings would include water-soluble silicate systems, silica sol systems, organic silicon, and inorganic polymer systems.
Common coating film-forming substances include: epoxy, rubber, polyurethane, silicone, acrylic, vinyl, resin, phenolic, polysiloxane, cellulose, fluorocarbon, nitro, alkyd, grease, amino, fluorine-based, and pigment and many other types of substances.
It is also important to note that in some applications, there are two composite forms of organic and inorganic coating. One is where the coating uses both organic and inorganic materials as the base materials in the coating production to make a composite coating, and the other is organic coatings and inorganic coatings that are used with combinations of each.
If you want to learn more about organic coatings and inorganic coatings, you can go to the appropriate blog to read up some more.
What Are The Application Fields For Coatings?
Coatings have a large range and versatility of applications. Coatings are thoroughly applicable in industry, construction, and decoration. Paint is not only for decoration, but it can have many more functions.
Water pipes used in fire suppression systems can be painted with the color red (for identification) to protect the steel from corrosion, however the coatings used protect the substrate to varying degrees; with corrosion-resistant and maintenance coatings for steel and concrete being applied in moderation, decorative coatings give steel and concrete specific reflective characteristics, e.g., high-gloss, satin, flat or matte.
Coatings are the unseen and celebrated performers of surface, and they are much-needed across many different sectors. Time to take a playfully insightful journey through the many worlds of coatings.
Architecture:
Imagine a land of protected buildings in gorgeous coats, enhancing the landscape either in terms of color or aesthetic and protecting the building from the elements, whether the coatings are working to protect a high-rise against pollution, or improve the visual appeal of a historic building – coatings speak to their many purposes.
Automotive:
From a land where you are zooming along the road viewing your automotive vehicle with eclectic coatings and finishes, coatings are doing their job to protect paint from corrosion on the body of the car, or gloss as you hit the remaining sunshine of the day.
Aerospace:
Similarly, there are coatings in the striking realm of Aerospace, where coatings protect airplanes from various ordeals faced high in the atmosphere, whether they be anti-corrosion coatings, thermal barrier coatings or coatings providing stealth capabilities, all coatings will work to enhance the capability of the airplane.
Electronics:
In the gentler world of electronics, coatings are the silent protectors of your beloved gadgets circuits, whether they be conformal coatings to electrical appliances to Coatings are all the rage when it comes to marine oceans! Anti-fouling coatings are there for us when barnacles try to hog ship hulls.
Marine Oceans:
Corrosion resistant coatings are there to work with the ocean, so that when we decide to use those structures and elements in the marine environment we have an impression of the purpose and advance as we originally thought.
Medical:
Now think of the coatings in the medical community. They play the role of quiet healers. Medical device coatings are responsible for creating a biocompatibility character so that implanting an object does not abjectly fit in the human body, while antimicrobial coatings battle the undisputed enemy of the healthcare world, coatings that present surfaces that will resist unwanted contaminants.
So what do coatings open up a universe of possibilities for applications? Coatings are almost magic where science meets art and functionality makes aesthetic sense.
Coatings are much more than layers, they are magic makers that ensure surfaces withstand and look appealing everywhere we encounter in life. So let us journey our way through this varied universe of coatings and celebrate the remarkable claims in all application domains!
What Do You Need To Know When You Are Making A Coating Selection?
As a person who has one toe in the coatings universe, I would like to call out a few ways that could be influential and improve your decision-making!
Purpose:
First, everybody should make the attempt to clarify what the reason for the coating is. Is it decorative, artistic purpose that is going to try to shine even in direct sunlight? Or are you after a that is going to support a tough coating to resist wear and corrosion? Knowing what the purpose is will establish context for the rest of the decision-making.
Substrate Type & Material Compatibility:
Let’s talk about your substrate, the substrate is the foundation for the all of your decision-making! Based on the materials used as the substrate (whether the chemical group is polyurethane, acrylic, amino, fluorine, phenolic, epoxy resin, etc.) use proper adhesive and appropriate additives.
Substrate materials respond differently to different types of additives, and each material has unique needs.
Environmental Conditions:
You must also factor in the environment that your coated product will face, will you subject the coating to different weather, varying temperature conditions, UV light exposure, exposure to corrosive chemicals, etc.
All of this will narrow your options to coatings that are resistant to the environmental factors expected. Any time the environmental conditions vary, you can expect variation in results.
Also, remember that anything that contaminates the coating prior to curing can damage the properties as it cures too. Understanding the environmental parameters will help you to make sure your coating will preserve the items you are coating for as long as possible.
Application Method:
The practical side of things matters too, ease of application, drying and curing conditions and time, whether or not the product is an application that requires specialized equipment, or likely needs multiple applications.
It’s important that you factor in time in the process, either finishing the coating process according to schedule and without wasting any of your or someone else’s time and resources taking unnecessary steps.
Performance Requirements:
Coatings are expected to “perform.” Each type of coating can perform differently. Your “scope” should specify your expectations for ease of cleaning, corrosion resistance, wear resistance, impact resistance, etc.
Performance characteristics should be adapted at each point of customizing the coating formula, relative to the intended use of the component parts.
Cost Issues:
You want to think about your budget like a prudent financial planner – consider what your costs are in total: the material costs, the application costs, and what future maintenance costs might be reasonable to anticipate.
Some coatings might be cost prohibitive to use initially, yet, provide a durable, sustainable coating for use over time that might justify the cost savings down the road.
Surface of Application:
Reflect on what the surface is made of, metal can be coated with a corrosion resistant finish but concrete should sometimes just be protected from wear.
Selecting coatings is similar to picking symphonies – each piece has to fit together and work well to create a masterpiece. Having looked at these items and reflect on your process you should ensure you’re creating a coating symphony that will last. Best of luck with your coatings!
What is the difference between coatings and paint?
When we get into the subject of enhancing surfaces, coating and painting, or the terms “coatings” and “paints” are frequently interchanged, but they have different characteristics and serve different functions.
Coatings and paints are very similar, but they also have some very key differences. So let’s look at what are the basic differences between normal paints and high-performance coatings:
Ingredients:
- Coatings: High-performance coatings are designed for protection and adhesion and can often be a polyurethane, epoxy resins, metals, and other specialty chemicals you would not generally find in typical paints. The formulations have a functional aspect with durability being the focus.
- Paints: Paints are used for applying color to a surface, therefore paints are much more basic and only consist of basic pigments, solvents and basic binders. The formulation is put together for applications and also for how it looks when it is finished.
Purpose:
- Coatings: Coatings do do have an aesthetic aspect to them, but their inherent purpose to prevent corrosion, avoid degradation and improve performance.
- Paints: Paints don’t have a performance aspect; they want you to see them as they are more about looks. They do provide a very basic level of protection, but mainly they bring color to surfaces, they are personal.
Here’s the tricks to coatings.
When looking to coatings, it is important to know the pros and cons to get an understanding of your needs. So, let’s talk about coatings and the good, the bad and the ugly.
What are the pros of coatings?
Coatings come with a bunch of benefits and create a protective layer between the metal surface and highly corrosive materials and environments, such as water and a variety of chemicals.
This layer protects the integrity of the surface and also protects from traffic or the chance of abrasion. In lots of industrial applications, items are exposed to corrosive environments, and to have coatings that resist chemical exposure is paramount.
In addition to just protection, coatings can also limit degradation and discoloration from UV exposure. They offer a greater life cycle. Besides protection, coatings can also add to the visual enhancement of surfaces.
Sometimes there are coatings that are made to withstand extremes in temperatures which could be valuable if you live in one of those places where you have to be prepared for crazy weather one day!
Simply put, coatings are more than aesthetics; they create a barrier that prevents water from penetrating the surface and creates issues in the material like rot and decay.
The smooth surface of the coated material is very often easier to clean and maintain, contributing again to durability and better salt mitigation.
What are the drawbacks of coatings?
While coatings can be beneficial in many cases, there are also some drawbacks to coatings. Coatings can be complex because implementing coatings correctly can be difficult and involves considerable surface preparation and application procedures.
The cost of the coating material and application processes can be a major financial burden, especially for large applications and when budgeting becomes especially constricted.
Certain coating formulations still will contain volatile organic compounds (VOCs) like carbon dioxide and sulfur oxides that are harmful to the environmental good.
Under significant impacts or abrasive conditions, nearly all coatings can be agitated and negated! Depending on the substrate type or application conditions, surface adhesion can be difficult.
In some cases, specific coatings may have a lengthy curing time, meaning that the equipment may not be operational until the coating is completely dry.
Also, some coatings can fade if exposed to UV light. Incompatibility with certain materials requires exhaustive research prior to installation, and with some coatings, understand their effectiveness is limited to required temperature ranges.
In closing, coatings are fairly much of a complex mix of as much benefits and as much difficulty. Understanding both advantages and disadvantages of coatings can help users make informed decisions about what coatings to actually use, based on project needs and goals.
In this paint journey, we have only skimmed the surface of the huge world of paint. Whether you work in coatings or are new to the space, it is our hope that this article will give you a spark of inspiration.
Paint, like our name, is a world of colour and creativity, just waiting for all of us to jump into. Join us on this field of miracles and ignite the future paint passion within! Let’s look together into the looking glass – at the future development trends in coatings that is worth getting excited about.