Types of Powder Coating Finishes Available

Part of the entire aluminum manufacturing process includes methods for creating a tough and durable finish, while making the metal look pleasing as well. One of these would be the application of powder coating finishes. Powder coating is a widely used process for coating metal parts. It is a type of surface finishing that uses a thin film to provide exceptional corrosion and chemical resistant properties, while being extremely aesthetic. This makes them a vital component of every powder coating operation.

Powder coating uses a dry powder, which is then heated to a very high temperature to melt the powder onto the part. The powder used is an alloy of metal oxides, which is then built up on the surface to create the new coating. Some of the reasons why powder coating is a popular choice is because it is easy to transport, it doesn’t require the part to be heated to a high temperature and it can be used in a wide range of applications.

Benefits of Powder Coating

Moreover, it has a number of benefits that create so much value for metals. One of these would be involving the lack of solvents, which means that no volatile organic compounds, or VOCs, are released. Thus, it is a material that is safer to work with, dispose of, and transport. In addition, they can be able to provide you with exceptional environmental benefits as well. Another benefit that powder coating finishes are known for would be offering a wide range of specialty effects that are typically difficult to achieve by going through the traditional coating methods. These specialty effects, thus, result in the metal being more scratch resistant, while being tougher and harder too.

Process of Applying Powder Coating

The process for applying powder coating finishes lies on using a powder spray gun. The spray gun, when triggered, charges the powder particles flowing through it electrostatically. The powder is drawn to the part via electrostatic attraction since the parts to be coated are grounded. The pieces are then cured in an oven, which melts and cross-links the powder over the part’s surface, creating a durable, scratch-resistant, and attractive finish.

Powder coating finishes can be used for various applications, primarily on metals. Which is why it is ideal to add on the industrial parts, medical devices, architectural applications, various automotive parts, household appliances, and many more. But before anything else, before having to come up with a decision of choosing to have powder coating finishes applied on the metals, you have to know and understand first the type of powder coating finishes available. This includes epoxy, polyester, epoxy-polyester hybrid coatings, and polyurethane. All of them have unique properties that are suitable for certain environments and uses too. Which is why it is important to make sure that you have the right type of powder, and choose the best color for a more appealing outcome.

Epoxy

One of the widely used powder coating finishes would be epoxies. It is actually the first powder coating to become commercially available, which has maintained its popularity within several industries over the years. It is known for its very durable properties, which offers a prominent quality of being chemical and corrosion resistant, resulting in providing an excellent hardness and toughness as well. Another advantage of this type of coating is that it is simple to use and comes in a variety of cure schedules. Epoxies cling to metals exceedingly well, and various metal pretreatments, such as phosphate coating and sandblasting, improve adherence too. In terms of the appearance of the epoxy powder coating finishes, they are actually very smooth and uniform.

The only drawback of epoxy powders is that they do not adhere to certain weathers and environments well. Too much sun exposure may cause them to fade and change their overall color. They can only withstand minimal UV exposure. With this, they also weather poorly, and often start to degrade on the surface after a while. Which makes epoxies only suitable to apply if the products were to be placed indoors.

Polyester

Another popular type of powder coating finish would be the polyester coating. It is commonly selected to be the type to apply on metals, primarily because it offers great value for money. Polyester offers good mechanical resistance, which includes being greatly flexible and can resist impact well. It is known for the highest exterior stability and performance too.

Moreover, this type of powder has the quality of curing better even at low temperatures. This makes it better for sensitive items. Polyesters are also resistant to yellowing after being over baked, making them very convenient and easy to use. They can also handle UV exposure as well, so they work well for both indoor and outdoor applications. It offers strong adhesion properties, and excellent gloss retention when exposed to UV rays. If compared to epoxies, they are stronger in terms of their weathering characteristics. But then, this type also offers a wider selection of colors, floss levels, and special effects too. These make it an ideal powder for most products.

Being a powder that is commonly utilized by most applications, it is not surprising that there are actually not that many drawbacks to polyesters. The only disadvantage of this type is that it only holds limited exterior durability. But if you will be coating metals that will be permanently placed outdoors, you can still use polyesters; but those that contain super durable properties as they need good wearability and durability.

Epoxy-Polyester Hybrid Coating

Mixing both the properties of epoxy and polyester is possible. It is the process of forming hybrid coatings that can withstand superior weather degradation properties. All while being extremely durable as well. This hybrid coating can be mixed in various ratios. It depends on how you will be emphasizing the unique characteristics of either the epoxy or polyester. This type of coating is widely utilized on products that require an appealing physical appearance. All while having good functional properties as well. They can be used in some of the areas in which epoxies are applied on. But they are typically used on indoor appliances and other household items.

When compared to a straight epoxy, the polyester improves over bake resistance and produces ultra-smooth, thin layers. The resins’ combination can also make them more cost-effective than pure epoxy. The polyester, on the other hand, reduces the epoxies’ corrosion and chemical resistance. But then, it doesn’t actually improve the product’s outside weatherability.

Polyurethane

Polyurethane is a type of powder coating that offers flexibility and hardness, which is typically utilized for moving parts. The versatility of polyurethane powders allows them to be utilized for both aesthetic and functional objects that are exposed to the elements. Their excellent weathering qualities, along with excellent anti-corrosion performance, humidity resistance, and resistance to a variety of solvents and lubricants, make them perfect for such applications.

Key Takeaway

The application of powder coating finishes are indeed a great choice and measure for various products, both for aesthetic and functional purposes. Each type of coating has their own unique properties and characteristics that best fit whatever your application is. And the type that you will be selecting must depend on what product you are applying it on. Whether it is for indoor applications or for outdoors, for instance. However, no matter what type you choose, it will still certainly be an excellent surface finish option that can be used to protect a lot of metals, utilized at several industries.