At Five Star New Materials, we understand that the brilliance of metallic paint lies not just in its visual appeal but in the science behind its formulation. As a leading manufacturer of high-quality aluminium paste, we are proud to play a key role in helping coatings manufacturers around the world achieve outstanding metallic finishes that are both beautiful and durable.

Aluminium paste is the heart of any high-performance metallic paint. It is responsible for the distinctive shimmer, depth, and colour travel (also known as the “flop effect”) that make metallic coatings so desirable in industries ranging from automotive to consumer electronics. But not all aluminium pastes are created equal. The particle size, shape, surface treatment, and dispersion quality all have a direct impact on the final appearance and performance of the coating.

At Five Star New Materials, we specialize in producing non-leafing and leafing aluminium pastes that are engineered for superior performance in a wide range of metallic paint systems. Our products are designed to deliver excellent orientation, strong reflectivity, and long-term stability, even under the most demanding environmental conditions. Whether you’re formulating a high-end automotive finish or a durable industrial coating, our aluminium pastes provide the consistency and reliability you need.

We also understand that formulating with aluminium paste requires a careful balance. Too little, and the metallic effect is weak. Too much, and you risk compromising the mechanical and weathering properties of the coating. That’s why we work closely with our clients to recommend the optimal aluminium paste loading for their specific application—typically between 5% and 10% for most metallic paint formulations.

In this blog, we’ll take a deep dive into the role of aluminium paste in metallic paint, including how it affects appearance, durability, and application performance. We’ll also explore how to test the weather resistance of your coatings and what to look for when selecting the right aluminium paste for your system.

Whether you’re a coatings formulator, a product developer, or simply curious about the science behind metallic finishes, this guide is designed to give you the insights you need to make informed decisions. And if you’re looking for a trusted partner in aluminium paste supply, Five Star New Materials is here to help you shine.

At Five Star New Materials, we understand the critical role aluminium paste plays as a vital metallic pigment. Manufacturers widely use it in metallic paints, especially in automotive and industrial coatings, to achieve unique metallic textures and dazzling effects. Here’s our complete guide to aluminium paste and metallic paint:

1. The Essential Characteristics of Our Aluminium Paste

Our aluminium paste provides the foundational elements for superior metallic paint applications.

Composition

We craft our aluminium paste from flake-shaped aluminium powder, combined with solvents (like mineral spirits or lipids), and a small amount of additives to create a consistent, paste-like dispersion.

Optical Effects

• Metallic Texture: Our precisely aligned aluminium flakes reflect light, creating a soft, desirable metallic sheen.
• Flop Effect: As your viewing angle changes, the depth and chromaticity of the colour shift. これは creates a bright face and a darker side, adding dynamic visual interest.

Classification

• Floating Aluminium Paste: The aluminium flakes float on the surface of the paint film, offering strong reflectivity but weaker resistance to ageing.
• Non-Floating Aluminium Paste: We ensure the aluminium flakes are uniformly distributed within the paint film. This type offers excellent ageing resistance, making it ideal for use in automotive paints.

2. The Composition and Features of Our Metallic Paint

Our metallic paint formulations deliver both stunning aesthetics and robust performance.

Basic Formulation

• Resin: We use acrylic, polyurethane, and other resins to provide superior adhesion and durability.
• Aluminium Paste: Our aluminium paste typically comprises 5% to 20% of the formulation, defining the distinctive metallic effect.
• Transparent Pigments: We incorporate pearlescent pigments or dyes to enhance colour depth.
• Solvents and Additives: We carefully select these to adjust viscosity and drying speed, ensuring optimal application.

Features

• High Decorative Appeal: Our glittering effects significantly enhance visual appeal.
• Ageing Resistance: Our high-quality metallic paints effectively resist UV radiation and corrosion. Automotive metallic paints, for example, consistently pass rigorous QUV tests.
• High Application Standards: We emphasize precise control of spraying parameters—such as gun distance and air pressure—to prevent mottling or inconsistencies in the finish.

3. Applications of Our Metallic Paint

Five Star New Materials’ metallic paint solutions cater to a broad range of industries.

• 自動車産業: You’ll find our products in car body paints (e.g., “metallic silver,” “pearl white”) and wheel coatings.
• Industrial Coatings: We supply manufacturers for appliance casings and machinery decoration.
• Inks: Our aluminium paste creates metallic effects in packaging materials.
• Plastics Coating: Our solutions are perfect for electronic device casings, including mobile phone back covers.

4. Operational Guidelines for Our Aluminium Paste

To achieve optimal results with our aluminium paste, we recommend following these operational guidelines.

• Anti-Settling: Our aluminium paste can settle, so we advise thoroughly stirring it before use.
• Anti-Oxidation: Prevent contact with acids and alkalis to avoid blackening due to aluminium flake oxidation.
• 安全性: Aluminium powder is a flammable product. Please keep it away from sources of ignition and store it in a cool, well-ventilated area.

5. Challenges and Solutions

We proactively address common challenges our customers face to help you achieve perfect metallic paint finishes.

Challenge 1: Film Mottling (Unevenness)

• Reason: Applying the spray too thickly or allowing the solvent to evaporate too quickly can cause mottling.
• Solution: Adjust your spraying parameters, and consider adding a slow-drying solvent.

Challenge 2: Insufficient Hiding Power

• Reason: This usually occurs when the aluminium paste content is too low or the particle size is too fine.
• Solution: Increase the dosage of aluminium paste or use a coarser particle size.

What Proportion of Aluminum Paste Should You Use in Metallic Paint?

The ideal Proportion of aluminium paste in metallic paint varies based on the specific application and quality requirements. Here are our recommendations for everyday use scenarios:

Application Type Recommended Aluminium Paste Proportion Notes

High-End Automotive Metallic Paint: 5% – 8%. We use this range to achieve an excellent flop effect, deep gloss, and superior weather resistance. This Proportion delivers a balanced metallic look without compromising durability.

General Industrial Metallic Paint: 5% – 10%. This range provides an intense metallic sensation and good protective properties for applications such as machinery, appliances, and building materials. It offers a cost-effective balance of aesthetics and performance.

Metallic Ink for Packaging: 10% – 15%. For inks where a substantial visual impact and high metallic lustre are paramount, we recommend a higher concentration. これは creates a vibrant, eye-catching metallic effect on packaging.

Plastic Metallic Coating (e.g., Electronics) – 8% to 12%. We adjust this Proportion to achieve specific textures and visual depth on plastic substrates. It balances metallic aesthetics with the coating’s requirements for adhesion and flexibility.

Furthermore, in some highly decorative industrial coatings or specialized formulations, the aluminium paste proportion may reach as high as 15% to 20%. However, this is quite rare and typically reserved for products demanding a firm metallic feel or unique visual effects.

We advise caution, as excessively high proportions can diminish the paint film’s properties, such as adhesion and ageing resistance. Therefore, in practical applications, you should adjust the Proportion based on your specific formulation system, application conditions, and performance requirements.

How Does Aluminum Paste Proportion Impact Metallic Paint’s Aging Resistance?

The Proportion of aluminium paste significantly affects the ageing resistance of metallic paint. Here’s how:

✅ 1. Insufficient Proportion (e.g., <3%)

• Insufficient Metallic Feel: A low quantity of aluminium flakes results in a weaker reflective effect, making the paint film’s metallic lustre less pronounced.
• Poor Shielding Performance: The aluminium flakes provide inadequate physical shielding, allowing UV light and moisture to penetrate more easily, which accelerates the ageing of the paint film.
• Reduced Ageing Resistance: Without a sufficient aluminium layer to reflect UV light, the resin matrix degrades more rapidly, resulting in issues such as peeling and loss of gloss.

✅ 2. Appropriate Proportion (5% – 10%)

• Optimal Balance: This range represents the common Proportion for most industrial metallic paints, including automotive coatings, wheel coatings, and industrial anti-corrosion paints.
• Excellent Ageing Resistance:
  • The aluminium flakes create a dense metallic barrier, effectively reflecting UV light and preventing the resin from photodegradation.
  • They enhance the coating’s water resistance, salt spray resistance, and overall resistance to ageing.
• Strong, Not Exaggerated, Metallic Feel: This Proportion delivers a strong “flop effect“ and visual depth.

⚠️ 3. Excessive Proportion (>13%)

• Reduced Ageing Resistance (Paradoxically):
  • Too many aluminium flakes can lead to uneven dispersion, causing localized aggregation and compromising the paint film’s compactness.
  • A high proportion of aluminium flakes may weaken the resin’s continuity, reducing the paint film’s flexibility and adhesion, which can result in cracking and detachment.
• Diminished Application Characteristics: This can lead to issues like “powder spitting,“ spray gun clogging, and poor levelling.
• “Overexposed“ Metallic Feel: While the metallic feel is strong, the visual depth decreases, and the finish can appear mottled or inconsistent.

✅ 4. The Advantage of Coated Aluminium Paste

Using resin- or silica-coated aluminium paste (such as non-floating or double-coated types) significantly improves ageing resistance, maintaining stability even at higher proportions. The coating effectively isolates oxygen, moisture, acids, and alkalis, preventing aluminium flake oxidation and extending the paint film’s lifespan.

Suppose you are developing high-ageing-resistance metallic paints (e.g., automotive topcoats, outdoor equipment paints). In that case, we recommend maintaining the aluminium paste content between 5% and 10%: Prioritise coated, non-floating aluminium paste for optimal ageing resistance and decorative efficiency.

How Do We Test the Ageing Resistance of Metallic Paint?

At Five Star New Materials, we rigorously test the ageing resistance of our metallic paints through both artificial accelerated ageing tests and natural climate exposure tests. Our goal is to simulate the effects of UV light, humidity, and temperature changes, and then evaluate the paint’s durability and retention of appearance.

1. Artificial Accelerated Ageing Tests (Common Methods)

1. Ultraviolet (UV) Accelerated Weathering Test

• Equipment: We utilise a UV-accelerated weathering tester (such as a QUV).
• Standards: We apply UV-A or UV-B lamps to simulate the UV component of sunlight and use condensation or spray systems to simulate moisture.
• Test Duration: Typically 500 to 1000 hours, which can equate to 1 to 3 years of outdoor exposure.
• Evaluation Metrics:
  • Colour change (colour difference)
  • Gloss retention (ISO 2813)
  • Peeling level (EN ISO 4628-6)
  • Blistering, cracking, and chalking (EN ISO 4628-2/5/6)

2. Xenon Arc Lamp Accelerated Weathering Test

• Equipment: We utilize a xenon arc lamp accelerated weathering tester (either water-cooled or air-cooled).
• Characteristics: The spectrum of this lamp more closely matches natural sunlight, making it suitable for metallic paints requiring high colour stability.
• Standards: We adhere to standards such as ISO 11341 and ASTM G155.

2. Natural Climate Exposure Tests

• Method: We place coated samples at outdoor exposure sites (e.g., subtropical, desert, or marine climate zones) for extended periods.
• Duration: Typically 6 months, 12 months, or longer.
• Advantages: The results more closely reflect actual use scenarios.
• Disadvantages: These tests are time-consuming and heavily influenced by environmental factors, such as climate.

3. Evaluation Criteria and Indicators

To meet high-performance standards, our metallic paint ageing resistance tests comply with the following criteria, often aligning with EU Green Public Procurement (EU GPP) standards:

Test Item Standard Pass Criteria

Gloss Retention ISO 2813 (Gloss at 60°) ≥80% after accelerated ageing (e.g., QUV 500h) or natural exposure (6 months).

Colour Difference ISO 7724-3 (ΔE*) ≤3.0 after accelerated ageing or natural exposure.

Cracking EN ISO 4628-4 (Assessment of degree of cracking), not exceeding rating 1 (slight cracking) after accelerated ageing or natural exposure.

Blistering EN ISO 4628-2 (Assessment of degree of blistering) Not exceeding rating 1 (few, small blisters) after accelerated ageing or natural exposure.

Chalking EN ISO 4628-6 (Assessment of degree of chalking) Not exceeding rating 1 (slight chalking) after accelerated ageing or natural exposure.

Adhesion ISO 2409 (Cross-cut test) Not exceeding rating 1 (minor flaking at edges of cuts) after accelerated ageing.

4. Other Supporting Test Methods

• Salt Spray Test: We assess the 耐食性 of metallic paint in corrosive environments, commonly used for automotive and industrial coatings (ISO 9227).
• UV Transmittance Test: We indirectly evaluate the ageing resistance of the coating by measuring its ability to block UV rays.

5. Summary and Recommendations

We recommend a combination of tests for a more comprehensive assessment, including artificial accelerated ageing (e.g., QUV 500h), salt spray testing, and natural exposure (6 months).

For high-demand applications (like automotive topcoats, outdoor building materials), we strongly recommend combining Xenon lamp ageing with natural exposure and a salt spray test.

If you have specific product types or uses in mind (e.g., car wheels, metal curtain walls), we can further recommend suitable testing standards tailored to your needs.

How Long Do Metallic Paint Ageing Resistance Tests Take?

The duration of metallic paint ageing resistance tests depends on the specific testing standard employed, primarily falling into two categories: artificial accelerated ageing tests and natural climate exposure tests. The time required for each method varies:

1. Artificial Accelerated Ageing Tests (Laboratory Simulation)

1. UV Accelerated Weathering Test

• Test Duration: Typically ranges from 500 to 2000 hours.
• Applicable Standards: We adhere to standards such as ISO 4892-3 and GB/T 16422.3.
• Characteristics: This method rapidly assesses coating ageing by simulating sunlight’s UV rays combined with condensation or spraying to simulate moisture.

2. Xenon Arc Lamp Accelerated Weathering Test

• Test Duration: Usually 500h, 1000h, 1500h, or 2000h.
• Applicable Standards: We follow standards such as GB/T 1865-2009 and ISO 11341.
• Characteristics: This method’s spectrum more closely matches natural sunlight, making it suitable for metallic paints with high demands on colour and gloss stability, such as automotive topcoats. For example, we test diamond silver-grey metallic paint for 500 to 2000 hours under xenon lamp ageing conditions, evaluating characteristics such as gloss loss, colour fading, and blistering.

2. Natural Climate Exposure Tests (Real Outdoor Environment)

• Test Duration: Typically 6 months, 12 months, 18 months, 24 months, or even longer.
• Applicable Standards: We adhere to standards such as GB/T 9276-1996, “Method for natural weathering exposure test of coatings.“
• Characteristics: These results are more realistic and reliable, but require a longer time. They are suitable for validating the accuracy of artificial ageing results. For instance, the consistency between metallic paint exposed outdoors for 6 months and artificially aged for 1000 hours is very strong.

Recommended test time

In summary:

• Artificial Accelerated Ageing: We utilize this method for rapid assessment. The cycle is short (hundreds to thousands of hours), but natural exposure verification is necessary.
• Natural Exposure Tests: These are the most realistic but are time-consuming (usually over a year), making them suitable for final validation.

Aluminium paste is far more than just a decorative additive—it’s a critical functional component that defines the performance and visual identity of metallic paint. From the way it reflects light to how it protects the underlying substrate, the quality of the aluminium paste you choose will directly influence the success of your coating system.

At Five Star New Materials, we are committed to delivering aluminium paste solutions that meet the highest standards of quality, consistency, and innovation. Our products are trusted by formulators worldwide for their exceptional metallic effects, robust weather resistance, and ease of application. Whether you’re developing a premium automotive finish, a durable industrial coating, or a stylish consumer electronics shell, our aluminium pastes are engineered to help you achieve your goals.

We also understand that every application is unique. That’s why we offer customised solutions and technical support to help you optimize your metallic paint formulations. From selecting the correct particle size to adjusting the paste loading for optimal weatherability, our team is here to guide you every step of the way.

As demand for high-performance, visually striking coatings continues to grow, the role of aluminium paste in metallic paint will only become increasingly important. By choosing a reliable supplier like Five Star New Materials, you’re not just getting a product—you’re gaining a partner who understands your challenges and shares your commitment to excellence.

Thank you for reading our guide. We hope it has provided valuable insights into the science and application of aluminium paste in metallic paint. If you have any questions or would like to request samples or technical data, please don’t hesitate to contact us. Let’s work together to create coatings that not only protect but also inspire.

At Five Star New Materials, we are dedicated to providing the highest quality aluminium paste and ensuring that your metallic paint applications achieve superior performance and longevity. What other aspects of metallic paint or aluminium paste would you like us to explore?