1. Introduction
Fluorocarbon coating refers to coatings using fluoropolymers as the primary film-forming material. Also known as fluorocarbon paint or fluoropolymer coatings, it stands out due to the strong carbon-fluorine bonds and the high electronegativity of fluorine, resulting in superior performance.
Key characteristics include:
Excellent weather resistance
High and low temperature resistance
Excellent chemical resistance
Non-stick surface, low friction
After decades of rapid development, fluorocarbon coatings are widely used in construction, chemical, electronics, machinery, aerospace, and home furnishing products.
2. Types of Fluorocarbon Coatings
The most widely used types include:
2.1 PTFE (Polytetrafluoroethylene)
– As the earliest type of fluorocarbon coating to achieve industrial application, PTFE is renowned for its extreme heat resistance and chemical stability—its continuous operating temperature range is 180-260℃, it can withstand temperatures above 300℃ for short periods, and it hardly reacts with any known chemical substances (reacting only with a very few substances such as molten alkali metals and fluorine at high temperatures). From a process characteristics perspective,
2.2 PVDF (Polyvinylidene Fluoride)
The core advantage of PVDF coatings lies in their balanced comprehensive performance: on the one hand, they have excellent weather resistance, maintaining a service life of over 20 years in outdoor exposure environments, with a gloss retention rate exceeding 70%, and effectively resisting chalking and fading caused by ultraviolet radiation; on the other hand, their application process is relatively flexible, employing spraying, roller coating, etc., with a curing temperature typically between 180-220℃, making them suitable for common building substrates such as aluminum profiles and color steel plates. In practical applications, PVDF coatings are widely used in aluminum panels for building curtain walls, metal roofs, outdoor advertising signs, etc., all using PVDF fluorocarbon coatings as protective and decorative coatings.
2.3 FEVE (Fluorovinyl Ether)
FEVE fluorocarbon coatings can react with isocyanate curing agents at room temperature (5-35℃) to form a complete coating, without the need for high-temperature baking equipment. This characteristic greatly expands the application scenarios of fluorocarbon coatings. They can be used not only for large components in on-site construction (such as bridge steel structures and outdoor sculptures), but also for substrates that are not heat-resistant, such as wood, plastic, and glass. Furthermore, FEVE fluorocarbon coatings offer a wide range of adjustable gloss levels (from matte 30° to gloss 90°), rich color choices, and good flexibility, making them less prone to cracking when the substrate is slightly deformed. Currently, they are widely used in high-end furniture finishes, wooden doors and windows, and plastic shells, becoming a "universal" fluorocarbon coating for both civilian and industrial applications.
3. Advantages of Fluorocarbon Coating
3.1 Excellent Corrosion Resistance
Fluorocarbon coatings are chemically inert and resistant to acids, alkalis, salts, and solvents. The coating is tough, impact-resistant, and abrasion-resistant. In industrial settings, when fluorocarbon coatings are applied to steel storage tanks, even after long-term storage in 30% sulfuric acid or 20% sodium hydroxide solutions, the coating shows no blistering, peeling, or discoloration after a 1000-hour immersion test. In marine environments, metal components coated with fluorocarbon paint show less than 0.1% corrosion after 5000 hours of salt spray testing (simulating a high-salt-spray marine environment), far superior to traditional epoxy coatings (which typically show over 5% corrosion after 2000 hours of salt spray testing). Furthermore, fluorocarbon coatings not only exhibit strong chemical stability but also excellent physical properties—a coating hardness of up to 2H (pencil hardness test), impact strength ≥50cm (drop ball impact test), and a wear resistance (Taber abrasion test) with a weight loss of less than 0.5mg per 1000 revolutions, effectively resisting impacts and friction during daily use and preventing coating damage that could expose the substrate.
3.2 Low Maintenance and Self-Cleaning
In practical applications, dust, oil, and other stains are difficult to adhere to the fluorocarbon coating surface on building exteriors. Even if they do adhere, they will naturally rub off under rainwater, eliminating the need for regular manual cleaning. Data from a building curtain wall project shows that exterior walls using fluorocarbon coatings can reduce the number of cleanings per year from 2-3 times with traditional coatings to zero, resulting in cumulative maintenance cost savings exceeding 30% of the initial coating cost over ten years. In the industrial equipment sector, such as food processing workshops where pipes are coated with fluorocarbon coatings, material residues do not easily adhere, requiring only a small amount of water for cleaning. This reduces the use of cleaning agents, lowers equipment cleaning time, and improves production efficiency.
3.3 Strong Adhesion
Fluorocarbon coatings exhibit excellent adhesion to a variety of substrates. This characteristic stems from their special formulation design—adhesion promoters added to the coating form a chemical bond with the substrate surface, while the coating's own molecular structure physically interlocks with the substrate surface texture. For metal substrates, the adhesion of fluorocarbon coatings (cross-cut adhesion test) to common metals such as copper, stainless steel, aluminum, and steel can reach grade 0 (the highest grade, no peeling). For plastic substrates, adhesion to PVC, polyurethane, and ABS can also reach grade 1 after surface pretreatment (such as plasma treatment). For inorganic substrates, it also exhibits stable adhesion to cement, fiberglass, and ceramics. This advantage allows for wide application to components of different materials, avoiding the hassle of changing coating types due to substrate differences and reducing construction complexity.
3.4 High Decorative Value
Fluorocarbon coatings can achieve a gloss level exceeding 80% (measured with a 60° gloss meter), maintaining a vibrant appearance for decades. The decorative advantages of fluorocarbon coatings are reflected in both gloss and color stability. In terms of gloss, by adjusting the coating formulation, a full range of finishes can be achieved, from matte (gloss < 30%) to high gloss (gloss > 90%). High-gloss fluorocarbon coatings, measured with a 60° gloss meter, can exceed 80% gloss, exhibiting high surface smoothness and creating a mirror-like decorative effect. Regarding color stability, fluorocarbon coatings use highly weather-resistant pigments (such as inorganic metal oxide pigments), and the fluoropolymer molecules effectively block UV damage to the pigments, resulting in extremely strong color retention. Outdoor exposure test data shows that after 10 years of sun exposure, the color difference (ΔE) of fluorocarbon coatings is still less than 1.5 (almost imperceptible to the human eye), while traditional acrylic coatings show a color difference exceeding 3.0 after 3 years under the same conditions. This long-lasting decorative property makes it highly competitive in applications requiring high aesthetics, such as building facades, high-end furniture, and outdoor signage.
3.5 Long-term Weather Resistance
The fluorocarbon coating has a service life exceeding 20 years, preventing chalking, fading, and UV degradation. Weather resistance is one of the core advantages of fluorocarbon coatings, with a service life far exceeding that of traditional coatings. In ordinary outdoor environments, fluorocarbon coatings can last over 20 years, and even in harsh environments (such as high-temperature, high-humidity, and high-salt-spray areas), they can last over 15 years. This is manifested in three main dimensions: First, anti-chalking ability: under long-term UV exposure, the resin molecules of the fluorocarbon coating do not easily decompose, and the coating surface will not exhibit "chalky" chalking. After 15 years of outdoor exposure, the chalking level remains at 0 (no chalking). Second, anti-fading ability: as mentioned earlier, the color stability is excellent, with no significant fading even after long-term use. Third, crack resistance: fluorocarbon coatings possess good flexibility (elongation at break ≥15%), which can adapt to the thermal expansion and contraction of the substrate due to temperature changes, preventing the coating from cracking. This long-term weather resistance means that components using fluorocarbon coatings do not require frequent renovations, significantly reducing maintenance costs throughout their lifespan.
4. Disadvantages of Fluorocarbon Coatings
4.1 Stringent Application Requirements
Oil-based (solvent-based) fluorocarbon coatings require specific temperature and humidity conditions for application—the optimal application temperature is 15-30℃, and the relative humidity must be below 75%. If the temperature is too low (<10℃), the coating curing speed will be significantly slowed down, and incomplete curing may even occur; if the humidity is too high (>80%), the coating surface is prone to "whitening," affecting appearance and performance. More importantly, the quality of surface pretreatment directly determines the coating effect: if the substrate surface has oil stains, rust, or impurities, and the coating is sprayed before thorough cleaning, it will lead to decreased coating adhesion, making it prone to cracking and peeling later. For example, in a steel structure project, due to the failure to thoroughly remove the oxide scale from the steel surface, the coating peeled off over a large area after only one year, requiring reapplication and resulting in wasted costs.
4.2 High Cost Compared with traditional coatings
From a material cost perspective, fluorocarbon coatings are typically 3-5 times more expensive than traditional acrylic coatings, and PVDF fluorocarbon coatings can even be 6-8 times more expensive than traditional epoxy coatings. From a construction cost perspective, some fluorocarbon coatings (such as PTFE and PVDF) require high-temperature curing, necessitating specialized baking equipment, resulting in higher equipment investment and energy costs. For example, the cost of aluminum panels for building curtain walls using PVDF fluorocarbon coatings is 50-80 yuan per square meter higher than those using acrylic coatings. This high initial cost can be a significant constraint for small to medium-sized projects with limited budgets.
4.3 Solvent-based formulations pose environmental risks
To address the environmental issues of solvent-based coatings, water-based fluorocarbon coatings have emerged, with VOC content reduced to below 50g/L, meeting environmental requirements. However, compared to solvent-based fluorocarbon coatings, water-based products are slightly inferior in terms of weather resistance and chemical resistance. Outdoor exposure tests show that after 8 years of sun exposure, water-based fluorocarbon coatings retain approximately 60% of their gloss, while solvent-based PVDF fluorocarbon coatings retain over 75% of their gloss during the same period. Regarding chemical resistance, water-based fluorocarbon coatings show slight discoloration after immersion in a 5% hydrochloric acid solution for 500 hours, while solvent-based products show no significant change after 1000 hours under the same conditions. Furthermore, the application of water-based fluorocarbon coatings is more sensitive to humidity, and sagging is more likely to occur in high humidity environments, resulting in a narrower application window.
4.4 Safety risks exist during high-temperature decomposition
Fluorocarbon coatings are highly stable within their normal operating temperature range (typically ≤260℃). However, in extreme conditions such as fires, when temperatures exceed their decomposition temperatures (PTFE decomposition temperature approximately 400℃, PVDF decomposition temperature approximately 310℃), they release toxic gases (such as hydrogen fluoride and carbon tetrafluoride). These gases are highly corrosive and can cause serious damage to the human respiratory tract if inhaled, while also damaging fire-fighting equipment and the environment. Therefore, in scenarios with a high risk of high-temperature fires (such as high-temperature workshops in chemical plants and kitchen exhaust ducts), the use of fluorocarbon coatings requires the additional provision of a comprehensive fire-fighting and ventilation system to reduce safety hazards.
5. Advantages Compared to Other Materials
5.1 Superior Weather Resistance Compared to Traditional Coatings
The core advantages of fluorocarbon coatings lie in their weather resistance and service life. Traditional acrylic coatings typically have an outdoor lifespan of 5-8 years, while epoxy coatings (mainly used indoors or in corrosive environments) have an outdoor lifespan of only 3-5 years. Fluorocarbon coatings, however, can last for over 20 years. For example, building exteriors coated with acrylic paint require renovation every 8 years, while those coated with fluorocarbon paint can last for 20 years without renovation. Over a 20-year period, the total maintenance cost (including materials and construction) of fluorocarbon coatings is only about 40% of that of acrylic coatings. Furthermore, fluorocarbon coatings far surpass traditional coatings in chemical and temperature resistance: while epoxy coatings have good chemical resistance, they have poor weather resistance and are prone to chalking after long-term outdoor exposure; acrylic coatings have moderate weather resistance but weak chemical resistance and cannot withstand strong acids and alkalis, while fluorocarbon coatings achieve excellent performance in both weather resistance and chemical resistance.
5.2 Easier to apply and renovate compared to aluminum composite panels
Aluminum composite panels need to be pre-fabricated into fixed-size sheets in the factory and then transported to the site for installation. This results in poor adaptability to irregularly shaped components (such as curved curtain walls and complex wall designs), and requires numerous connectors during installation, leading to a long construction period. Fluorocarbon coatings, on the other hand, can be directly sprayed onto the substrate surface on-site, achieving uniform coating regardless of whether the substrate is flat or irregularly shaped. The construction period is shortened by more than 30% compared to aluminum composite panels. Regarding renovation, if aluminum composite panels experience localized damage, the entire panel needs to be replaced, which is costly and complex. However, if fluorocarbon coatings are damaged locally, only the damaged area needs surface treatment and recoating, making the renovation cost only 1/5 of that of aluminum composite panels, without affecting the overall appearance.
5.3 Fluorocarbon coatings also excel in balancing decorative effect and economy
Compared to high-end decorative materials (such as natural stone and metal sheets), fluorocarbon coatings can simulate the texture of natural stone and the feel of metal through color and gloss adjustments, achieving a decorative effect close to high-end materials, but at only 1/3 the cost of natural stone and 1/2 the cost of metal sheets. Furthermore, fluorocarbon coatings are significantly lighter than natural stone and metal sheets—the dry film thickness of a fluorocarbon coating is typically 40-80 μm, weighing only 0.05-0.1 kg per square meter, while natural stone can weigh 20-30 kg per square meter, and metal sheets weigh 5-10 kg per square meter. This lightweight advantage can significantly reduce the load on building structures and decrease structural design costs. Especially in high-rise building curtain wall projects, it can effectively improve structural safety and avoid safety hazards caused by excessive material weight.
6. Conclusion
Fluorocarbon coating is a high-end, high-performance solution suitable for projects requiring long-term durability, high decorative appeal, and excellent weather resistance. Although the initial cost is higher, its low maintenance requirements and service life of over 20 years make it an ideal investment for architectural and industrial applications.
