Written by Abigail June 24, 2024
What is powder coating?
Powder coating is a dry finishing process that has gained popularity due to its efficiency and environmental benefits. Unlike traditional liquid paints, powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. Instead, it is applied as a free-flowing, dry powder, typically using an electrostatic method, and then cured under heat or with ultraviolet light.
The powder used for coating is a mixture of finely ground particles of pigment and resin, which is sprayed onto a surface to be coated. The charged powder particles adhere to the electrically grounded surfaces until heated and fused into a smooth coating in a curing oven. The result is a uniform, durable, high-quality, and attractive finish that is tougher than conventional paint coatings.
Powder coating is mainly used for the coating of metals, such as household appliances, aluminum extrusions, and automobile and bicycle parts. However, recent advancements have allowed for its application on non-metallic substrates like plastics, composites, carbon fiber, and MDF (medium-density fibreboard).
This process offers several advantages over traditional painting, including a thicker coating without running or sagging, minimal volatile organic compounds (VOCs) emissions, and the ability to create a wide range of specialty effects that would be impossible to achieve with other coating processes.
3DSPRO Powder Coating Service for 3D Printed Metal Part
Powder Coating Cost
The cost of powder coating can vary widely depending on several factors, including the size and complexity of the item, the type of material, the finish required, and the condition of the item before coating. On average, powder coating costs range from $75 to $300 per item. For specific items like car wheels, the cost can be between $50 to $180 each, while larger items like a car frame may cost between $1,000 to $1,500.
Key points that influence the cost of powder coating:
● Item Size & Weight: Larger items require more materials and labor, thus increasing the cost.
● Surface Area: The total surface area to be coated affects the price, with larger or irregular surfaces costing more.
● Coating Type: Specialty coatings that are resistant to high temperatures or corrosion may come at a higher price.
● Color & Finish: Custom colors and finishes can increase the cost compared to standard options.
● Design Complexity: Items with intricate designs or hard-to-reach areas might require more time and precision, leading to higher costs.
● Non-Metallic Surfaces: Special techniques are needed for non-metallic surfaces, which can increase labor costs.
● Item Condition: Additional preparation work to remove rust or old paint will add to the overall cost.
● Quantity: Bulk orders often reduce the price per item, offering savings for larger quantities.
● Turnaround Time: Expedited services may incur additional fees.
Image Source: Nordson
Powder Coating Types
Powder coatings come in various types, each with specific properties and applications suited to different needs.
Thermoset Powder Coatings
These are the most commonly used types of powder coatings. When cured, they react chemically to form a permanent bond. This reaction makes them insoluble and infusible. Thermoset coatings are known for their durability and resistance to chemicals, heat, and corrosion. They are often used in appliances, automotive components, and outdoor furniture.
Thermoplastic Powder Coatings
Unlike thermoset, thermoplastic coatings do not undergo a chemical change when cured, which means they can be remelted and reshaped. They are known for their high-impact resistance and flexibility. Common applications include coatings for car bumpers, bicycle racks, and other items that require a durable yet flexible finish.
UV-Curable Powder Coatings
These coatings are cured using ultraviolet light rather than heat, making them suitable for heat-sensitive materials. UV-curable coatings are fast to cure and environmentally friendly due to low energy consumption and no emissions. They are applied to a variety of substrates, including plastics, composites, carbon fiber, and MDF (medium-density fibreboard).
In addition to the main three categories, there are specialized types of powder coatings designed for specific applications, such as:
● Epoxies: Known for their excellent adhesion and corrosion resistance, they are ideal for protective coatings.
● Polyesters: Offer good durability and resistance to UV light, commonly used for outdoor furniture and automotive parts.
● Super Durable Polyesters: Provide enhanced durability and weather resistance, suitable for exterior architectural and industrial applications.
● Epoxy-Polyester Hybrids: Combine the properties of both epoxies and polyesters, offering good chemical resistance and stability under UV exposure.
● Fluoropolymers: These have exceptional chemical and weather resistance, often used in architectural coatings.
● Urethanes: Provide a high level of abrasion resistance and are often used in heavy-duty industrial applications.
Image Source: Custom Powder Solutions
The Process of Powder Coating 3D Printed Parts
Surface Preparation
The 3D-printed part is cleaned to remove any dust, grease, or residues. This step may involve washing with a solvent or a mild alkaline solution and is crucial for ensuring the powder coating adheres properly.
Pre-Treatment
Depending on the material of the 3D-printed part, a pre-treatment such as a chemical etching might be necessary to create a surface conducive to powder adhesion.
Applying the Powder
The powder is electrostatically charged and sprayed onto the surface of the part. The electrostatic charge ensures that the powder sticks to the surface evenly before it’s cured.
Curing
Once the part is coated, it is placed in a curing oven where the powder is melted and cross-linked to form a uniform film. The curing process typically involves heating the part to temperatures between 160°C and 200°C for a specific duration, depending on the type of powder used.
Cooling
After curing, the part is cooled in a controlled manner to avoid any thermal shock or deformation of the 3D-printed material.
Quality Check
The final step is to inspect the coated part for any defects or irregularities in the coating. A quality powder coating should be even, without drips or bubbles, and should fully cover the part’s surface.
Image Source: Moz Designs
Powder Coating Colors
The color possibilities for powder coating are virtually limitless, offering a vast spectrum of hues and finishes to meet the aesthetic and functional requirements of any project.
Powder Coating Colors Key Features:
1. Wide Color Selection. Powder coating technology allows for a diverse range of colors, from standard options to custom hues. You can choose from thousands of colors and shades, including but not limited to antique pink, anthracite gray, bottle green, chocolate brown, chrome, carmine red, and heather violet. Essentially, any color you can imagine is available in powder coating.
2. Custom Color Matching. For projects requiring a specific color match, custom colors can be created, which is particularly useful for corporate branding or when trying to match other elements in a product line.
3. Solid Colors. These are uniform colors without special effects. Solid colors are also achieved through Pantone, which is a standardized color-matching system.
4. Special Effects. Beyond solid colors, powder coatings can include textures and finishes that add depth and character to the final product. Options include metallics, fluorescents, translucent, and pearlescent, as well as textures such as wrinkles, hammertoes, and veins.
5. Durability of Colors. Powder coatings are known for their color retention and resistance to fading. This is especially true for formulations designed for outdoor use, which include UV-resistant properties to maintain vibrancy even with prolonged exposure to sunlight.
6. Finish Types. The finish is not just about color but also about the gloss level and texture. From high gloss to matte and flat finishes, the choice of gloss level can significantly affect the appearance of the color and the overall look of the coated item.
7. Environmental Considerations. When selecting a color, it’s also important to consider the type of powder coating, as some are better suited for interior applications, while others are formulated to withstand outdoor conditions.
Image Source: PowderWerx
Benefits of Powder Coating
Durability
Powder coatings create a hard finish that is far more resistant to scratches, chipping, abrasions, and corrosion compared to liquid coatings. It is ideal for high-use items and environments.
Long-Lasting Quality
The colors of powder-coated surfaces remain vibrant and do not fade easily over time, even under extreme conditions, which ensures that the aesthetic appeal of the coated item is maintained for longer periods.
Environmental Friendliness
Powder coatings are solvent-free and emit negligible volatile organic compounds (VOCs), making them a more environmentally friendly option.
Cost-Effectiveness
The process is generally more economical in the long run due to the durability of the coating and the reduced need for maintenance and re-coating.
Efficient Application
Powder coating allows for a more efficient curing and drying process, which can lead to faster production times and lower energy costs.
Versatility
With a wide range of colors and textures available, powder coating can be used for both functional and decorative purposes, and it can be applied to a variety of materials, including metals, plastics, and medium-density fiberboard (MDF).
Thicker Coatings Without Running or Sagging
Unlike liquid paint, powder coating can be applied in much thicker layers without running or sagging.
Reduced Health Risks
Since there are no solvents involved, there is a lower risk of health hazards for workers applying the coating.
Recycling Capability
Overspray can often be collected and reused, reducing waste and further enhancing the process’s sustainability.
Specialty Effects
Powder coatings can achieve finishes that are not possible with other coating processes, such as textures, metallics, and fluorescents.
Limitations of Powder Coating
Initial Cost
Setting up a powder coating line can be expensive due to the need for specialized equipment such as powder spray guns, curing ovens, and application booths.
Thickness Limitations
Powder coatings are limited in the thickness that can be achieved in a single application. Achieving thicker layers may require multiple passes, which can increase processing time.
Color Selection
Although there is a wide range of colors available, the selection may not be as extensive as liquid paints, especially when it comes to very specific shades or custom colors.
Complex Shapes
Powder coating can be challenging on complex shapes or parts with deep recesses, as the electrostatic spray process may result in uneven coverage.
Surface Preparation
Proper surface preparation is crucial for powder coating, and any imperfections on the surface can affect the final finish, which can add complexity and cost to the process.
Repair and Touch-Ups
Repairing or touching up powder-coated surfaces can be difficult. Unlike liquid paint, which can be easily touched up, powder-coated surfaces usually require a complete re-coating.
Flexibility
Powder coatings are generally less flexible than liquid coatings. It can be a disadvantage for materials that bend or flex, as the coating may crack.
Environmental Conditions
While powder coatings are durable, they can be susceptible to damage from prolonged exposure to UV light and extreme weather conditions.
Limited Substrate Use
Powder coating is predominantly used on metal substrates. While recent advancements have allowed for its application on other materials, there are still limitations.
Curing Process
The curing process requires high temperatures, which may not be suitable for all types of substrates, particularly those that are heat-sensitive.
Powder Coating Applications
Automotive Industry
Powder coatings are extensively used in the automotive sector for components such as wheels, bumpers, door handles, radiators, shock absorbers, and engine parts. They provide a durable and attractive finish that can withstand harsh conditions.
Appliances
In the appliance industry, powder coatings are applied to front and side panels of ranges and refrigerators, washer tops and lids, dryer drums, air-conditioner cabinets, and dishwasher racks. They offer resistance to abrasion, chemicals, and temperature cycling.
Outdoor Furniture
Powder coatings are ideal for outdoor furniture due to their UV resistance and ability to withstand weather elements, maintaining their color and finish over time.
Building & Construction
The building and construction industry benefits from powder coatings for architectural metalwork, aluminum extrusions, and structural steel, providing long-lasting protection and aesthetics.
Electrical/Electronics
Powder coatings are used for exterior housings in electrical and electronic industries, offering protection while maintaining the functionality of the components.
Non-Metallic Products
With advancements in technology, powder coatings are now also applied to non-metallic substrates like plastics, composites, and MDF, expanding their use beyond traditional metal products.
Aerospace Industry
The aerospace industry utilizes powder coatings for parts that require a high level of precision and durability, such as certain interior components and exterior aircraft surfaces.
Agriculture Industry
Farming equipment and machinery benefit from powder coatings as they provide a tough finish that can resist the wear and tear of agricultural activities.
Industrial Machinery
Heavy-duty industrial machinery is often powder-coated to protect against corrosion, chemicals, and mechanical stress, ensuring longevity and reliability.
Consumer Goods
Many everyday items, from bicycles to lighting fixtures and sports equipment, are powder-coated for enhanced appearance and protection.
Image Source: IFS Coating
Quality Powder Coating at 3DSPRO
At 3DSPRO, we are committed to delivering top-tier powder coating services tailored specifically for 3D-printed metal parts. Our 3D Plus™ powder coating service is designed to enhance the durability, appearance, and performance of metal printed parts.
We offer:
1. High Quality Powder Coated 3D-printed Metals. Our powder coating process is optimized for 3D-printed metal parts, ensuring that the unique contours and geometries are covered evenly and effectively.
2. Color Options for Small Batches. For small batch orders, we offer classic black and white powder coating colors. These options provide a sleek and professional finish, suitable for a variety of applications.
3. Extensive Color Range for Bulk Orders. When it comes to bulk orders, our capabilities expand to include a wide array of colors and effects. From vibrant hues to subtle tones, we can accommodate specific color requests to match your project’s needs.
4. Quality Assurance. Each part undergoes a rigorous quality check to ensure that the coating meets our high standards. We guarantee a consistent and flawless finish, free from defects such as drips, bubbles, or uneven textures.
5. Environmentally Responsible. Our powder coating process is environmentally friendly, producing minimal waste and virtually no VOC emissions. We strive to maintain a green operation while delivering superior results.
6. Expert Support. Our team of specialists is available to guide you through the selection process, ensuring that the powder coating aligns with the intended use and aesthetic of your parts.
7. Fast Turnaround. We understand the importance of meeting project deadlines, which is why we offer efficient turnaround times without compromising on quality.
8. Competitive Pricing. At 3DSPRO, we provide cost-effective powder coating solutions. Our pricing is transparent, with no hidden fees, ensuring you get the best value for your investment.
9. Customer Satisfaction. We are committed to customer service, which means we will do everything we can to meet your expectations. Your satisfaction is our top priority, and we guarantee the quality of every part.
