In the manufacturing and construction industry, balancing efficiency with aesthetic appeal is important. That’s where prepainted steel coils come in! They make your projects look visually captivating to end customers and also help them save money on energy bills. But what exactly are prepainted steel coils, and what are their types? How do they benefit manufacturers? Let’s find out the answers to all these!
What is Prepainted Steel Coil?
Typically, prepainted steel coils are metal sheets coated with a paint or protective layer in a continuous manner. The base steel is either galvanized or galvalume steel, and the entire process is often automated. You don’t have to worry about corrosion and rust, and you can choose from a variety of steel products in different colours to find the one that best suits your needs.
When examining its history, the process of painting metal using a continuous coating line was invented in the 1930s. Joseph L. Hunter, who was known for designing new machines to boost the productivity of his Venetian blind business, was the mastermind behind this discovery.
However, it wasn’t until 1967 that the first continuous spray painting line was introduced at Shotton Works. Then, from the 1980s till today, there have been many innovations in the continuous painting of steel. Machines these days can reach speeds of 200m per minute and even more.
How are Prepainted Steel Coils Made?
Now that you are aware of the basics of prepainted steel coils, let’s discuss their manufacturing process step-by-step:
- The process starts with the selection of base metals. Common options to explore include cold-rolled steel or galvanised steel.
- Next, a thorough cleaning of the coil is performed to make sure there is no dust, dirt, or other residues that can impact the paint’s adhesion.
- It’s treated with phosphate-based or chrome-free alternatives for enhanced stickiness. The primer is applied on both sides of the coils to further ensure the paint layer bonds well with the surface.
- After that, the final coating or paint is added, which can include polyester, polyurethane, or silicon-modified polyester.
- In the final step, the painted steel is kept in ovens, especially drying ovens, that cure the paint so it doesn’t come off easily during practical applications.
Benefits of Prepainted Steel Coils
The benefits of prepainted steel coils are substantial, which is why they are popular among businesses and homeowners alike. Increasingly, people are investing in them, and in the US alone, the pre-painted steel coil market generated revenue of USD 2,745.1 million in 2022. It’s expected to reach USD 3,551.3 million by 2030, which is huge. But what are the reasons behind this popularity? Let’s find out!
Corrosion Resistance
One of the major benefits of prepainted steel coils is corrosion resistance. For instance, when you apply a paint layer on stainless steel, it acts as a barrier protecting the steel from oxygen, moisture, and contaminants. There are no concerns related to material degradation due to rust and corrosion, which helps save money.
Aesthetic Appeal
When it comes to aesthetics, prepainted steel is definitely a winner. It is available in various colors, patterns, and finishes. You can easily choose the one that matches your project requirements. For example, if you are designing a modern commercial building, you can go with a sleek metallic finish.
Durability
Naturally, steel is a robust material with a long lifespan, usually lasting from a few decades to centuries. It can withstand dents and other impacts without bearing much damage.
When a paint layer is added, the steel coils become more durable than ever, resisting scratches, UV radiation, and pollution. You can rely on it for years, even in environmentally challenging areas or applications.
Energy Efficiency
Energy prices worldwide are very high; all hail changing political dynamics and supply and demand imbalance. In the US, the electricity prices currently stand at around 15.22 cents per kWh, making it quite difficult for businesses and homeowners to pay their energy bills.
However, there’s no need to worry, as prepainted steel coils come as saviours. This material has high solar reflectivity, so it doesn’t absorb heat from the sun. Hence, it can be used in buildings to lower energy costs associated with cooling the place.
Low Maintenance
The painted layer on the steel coils becomes pristine with just mild cleaning, which makes it quite low-maintenance. Rather than spending hours on its upkeep, businesses can use that time to make innovations in their offerings. If you need suggestions, here are some tips that help you maintain prepainted steel coils:
- Ensure there’s good ventilation to avoid moisture buildup between the laps of the coil.
- Do not stack steel coils, as this can lead to mechanical damage in some cases.
- For general cleaning, use a water-based emulsifier or an alkaline cleaner. After that, rinse thoroughly with fresh water and wipe it dry using a soft cloth.
- If the coating degrades, repaint it for long-term performance and a top-notch appearance.
Recyclable
Prepainted steel coils are totally recyclable. You can reuse it in the manufacturing process, and the coatings applied won’t hinder recycling. This helps you protect the environment and align your business with global green regulations.
Types of Coatings for Prepainted Steel Coils
Various coatings are applied to prepainted steel coils, including polyurethane, SMP, and polyester. Let’s discuss their key properties in detail:
- PVDF (Polyvinylidene Fluoride): It’s a high-performance fluoropolymer coating known for its non-reactive nature and excellent strength. The presence of carbon-fluorine bonds in its structure contributes to superior colour and gloss retention. PVDF on steel coils provides excellent durability and chemical damage resistance.
- PE (Polyester): This coating material is actually a synthetic resin in which the polymer units are linked by ester groups. It’s a free-flowing, dried powder that you apply to the steel using a spray gun. What truly makes it stand out among other types of coatings is that it’s cost-effective, low-waste, and offers benefits such as UV resistance.
- SMP (Silicone Modified Polyester): SMP combines polyester resins with silicone additives. This unique combination ensures top-notch resistance to chalking, fading, and weathering, allowing you to use it in harsh conditions without worrying about colour and gloss loss.
- PU (Polyurethane): Polyurethane is a versatile polymer that’s made by the reaction of a polyol and an isocyanate. It’s used as a steel coil coating because it provides a strong barrier against moisture and salt, as well as improves overall abrasion resistance.
How to Choose the Right Prepainted Steel Coils?
Now that you are aware of the various benefits of prepainted steel coils, you must wonder how you can choose the right one for your industrial projects. Whether you are creating automotives or manufacturing other equipment, here are some tips that make decision-making easy for you:
Share Clear Specifications
Most of the time, buyers send vague details to suppliers, such as “0.10mm PPGI steel,” but it’s not enough. Therefore, you must send clear specifications in this format:
- Base Metal Grade: ASTM A653 or any other
- Paint: Polyester, Polyurethane, or PVDF
- Paint Thickness: Top Coat and back coat thickness
- Desired Dimensions: Coil thickness, width, and weight
When you share accurate details, suppliers can provide you with the exact pricing and material that’ll meet and exceed your expectations.
Collaborate with Certified Suppliers Only
Nowadays, regulations surrounding steel products are tightening, requiring manufacturers to use only certified materials. Therefore, you must work with suppliers who provide consistent quality products and have the following certifications:
- ISO 14001
- ISO 9001
They should also provide you with factory test reports to showcase the chemical composition and mechanical properties of the prepainted steel coils.
Inspect the Quality
Don’t just trust the words; rather, inspect the quality of the product yourself before purchasing. Make sure the coil surface has no scratches, oil marks, or bubbles, and measure the paint thickness using a gauge. You can also hire a third-party inspection service before choosing the material for your application.
Choose the Right Type of Coil
Know that not each prepainted steel coil is suitable for a particular application. You must go through all the available coating types before making a decision.
- PVD Coating for Roofing
- PE Coating for Household Appliances Manufacturing
- SMP Coating for Other Industrial Uses
Applications of Prepainted Steel Coils
The applications of prepainted steel coils are diverse, ranging from furniture to household appliances and even automotive. Let’s look at a few:
- Construction: In the construction industry, it’s part of roofing sheets, wall cladding, garage doors, and gutters.
- Automotive: Interior panels and dashboards are often made of prepainted steel coils.
- Home Appliances: Used in the exterior panels of refrigerators, washing machines, and air conditioners.
- Furniture: Incorporate metal cabinets and frames to give your furniture a visually appealing look.
Other applications include food packaging, medical, and the energy sector.
Conclusion
Prepainted steel coils are quickly becoming popular among manufacturers as a durable material. If you wonder where you can get top-quality prepainted galvalume steel coils, Jinghua Zhaojian Steel has you covered. We have been providing steel products since 2010 and cater to the needs of manufacturers in 60 countries. So why wait? Get in touch with us today to have certified steel products!
