Powder coating is a modern, high-quality organic finish for metals and other materials. There are tons of benefits of powder coating over painting and other finishes. Check it out.
What is Powder Coating?
Powder coating was invented in the 1950's, and it's one of the fastest growing finishing technologies available. Currently, it represents 10% of all industrial finishing applications on the market.
The powder itself can be either a thermoplastic or thermoset polymer. Thermoplastics do not undergo a chemical change during the curing process, and so can be re-melted and reused if necessary. Thermoset polymers do change chemically in high temperatures, so they cannot be reused once they're applied. However, they tend to be more durable than thermoplastics. The powder can be made of polyester, polyurethane, acrylics, or epoxy.
The coating is applied via electrostatic charge. The dry powder is given a positive charge as it's shot through a special electrostatic gun, and it naturally adheres to the negatively charged, grounded metal piece. An oven heated up to 400 degrees finalizes the coating.
A powder coating's performance depends on the pretreatment of the product, and the powder's resin and pigment. The product should be stripped of any oils, residue, and rust beforehand for a higher quality coating.
This type of finish is great for a multitude of applications, both decorative and protective, consumer or industrial.
Powder Coating Process
Powder coating starts with pretreatment, which is usually some type of abrasive blasting such as sand or bead blasting. This process removes rust, oils, and any other materials that would prevent the powder from sticking to the product. If the product is being recycled, the blasting process can remove old coatings from the metal.
Once the surface is treated, the finish is applied. The powder is shot through an electrostatic gun, giving it an electric charge. The charge assists in a consistent, perfectly thick coating.
The product will then be moved to an oven where the powder gels, flows, and cures to create an even finish. Before the powder is cured, the piece should be handled with care - since it's only adhering through static, jostling or rubbing the surface can remove the powder.
Advantages of Powder Coating
No matter your main business concern - whether it's cost, quality, safety, or environmental - powder coating surpasses paint in nearly every category.
- Highly efficient - one coat and done, covers more area than many other finishes, less reworking
- Less waste overall - any over-sprayed powder can be collected and reused
- Lower energy costs
- Reduced disposal costs
- Cheaper than wet paint
- Completely cured within 20 minutes of leaving the oven - paint can take days to dry
- Twice as thick as most paints
- Can bend and yield with vibration and jarring
- Highly resistant to chipping, scratching, fading, corrosion, chemicals, and weather
- No drips or other application traces
- Huge array of finishing colors and textures - metallic, fluorescent, gloss, glitter, smooth, wrinkled, matte, etc.
- Incredibly durable
Aside from basic manufacturing safety standards (don't breathe it in or get it on your skin), powder coatings are incredibly safe to handle and use. Powder coatings are non-toxic and completely safe to be around during the coating process.They also do not pose:
- Long or short term health risks
- Fire hazards
- Workplace dangers
Powder coatings are very different than wet paint in this aspect as well. Wet paint can be flammable, carcinogenic, and very hazardous to employees if handled incorrectly.
Conventional painting processes can negatively impact the environment, but powder coating does not.
Powder coatings contain no solvents or volatile organic compounds (VOCs) which is a key factor in their environmental impact.
They can also be recycled or disposed of in landfills and have a low impact on the atmosphere. They're not hazardous - so there's no need for costly pollution control equipment.
Cons of Powder Coating
Despite all the massive benefits of powder coating, of course there will be some downsides.
For manufacturers, costs can be high to introduce the service. Powder coating requires spray materials, an electrostatic booth, and an oven. However, if the manufacturer is already equipped with these capabilities, this is not an issue.
Here are some other cons you should be aware of:
- Cannot be done on rubber or other materials that can be easily melted in an oven.
- Is not meant for a thin finish - thin coating can get a strange bubbly texture.
- Can be broken down if exposed to UV rays.
Smaller, less complex projects might be better off with a less complex finishing process if you're worried about cost. However, you can always talk to the vendor about their pricing and services if that is a concern.
Not All Powder Coating Suppliers Are Equal
Not every vendor will use the same powder manufacturer, booth, spray tools, etc. -- this can affect the range of colors that they offer and the size of the products they can service.
Not every vendor can take on very large or very small projects, so keep in mind what kind of production volume you're looking at.
While researching potential vendors, it's important to find the answers to each of these questions:
- Are they reliable?
- Do they make deliveries on time?
- Is their service high-quality?
- Are they compliant with U.S standards?
Based on the answers you find to each of these, you'll find the right vendor for your project.
Powder coating is a fantastic alternative to conventional paint, plating, and other finishes. It's quite cost-effective, durable, safe, and environmentally friendly.
If you're currently using wet paint as your finish, consider switching to powder coating to receive all of the benefits. Of course, there are other metal finishing options out there too:
Editor's note: This post was originally published in February 2016 and has been recently updated.