How to Choose Aluminum Composite Panels (ACP): A Guide to Fire Rating, Aluminum Thickness, Structure and Coating

Aluminum Composite Panels (ACP), also known as aluminum plastic panels, have become a core material in modern architecture and signage. Their combination of lightweight structure, high strength, and design flexibility makes them ideal for facades, curtain walls, interiors, and advertising systems.

However, selecting the right ACP is not a simple decision. The wrong choice can lead to safety risks, premature failure, or unnecessary costs. We break down the four critical factors—fire rating, aluminum thickness, core structure, and coating system—to help you make the most informed and cost-effective decision.

Fire Rating of ACP: The Most Critical Selection Factor

Fire safety is the top priority when selecting ACP, especially for public buildings, high-rise structures and exterior cladding. The fire rating of ACP is mainly determined by the core material and complies with international standards such as EN 13501 (Europe), ASTM E84 (USA) and GB 8624 (China). Here’s how to choose the right fire rating:

A2 Grade (Non-combustible)

• This is the highest fire rating for ACP, suitable for high-rise buildings, hospitals, schools, airports and other public places with strict fire safety requirements. The core material is non-combustible (such as mineral core), which does not burn or release toxic gases in case of fire. It meets the EN 13501-1 A2 classification and ASTM E84 Class A standards. If your project is in Europe, the Middle East or North America, A2 grade is often a mandatory requirement for exterior cladding.

B1 Grade (Flame-retardant)

• This grade is flame-retardant, meaning it does not easily catch fire and can self-extinguish after the fire source is removed. The core material is usually flame-retardant PE (polyethylene), which is suitable for low-rise buildings, interior decoration, signage and advertising panels. It complies with EN 13501-1 B1 and ASTM E84 Class B standards, and is cost-effective for projects with moderate fire safety requirements.

Non-flame-retardant (B3 Grade)

• This grade has no fire resistance and is only suitable for indoor non-load-bearing decoration in non-public areas (such as small indoor partitions, display stands). It is not recommended for exterior cladding or public buildings, as it poses significant fire risks.

Tip: Always check the fire rating certificate provided by the manufacturer to ensure it meets the local building codes of your target market (e.g., CE certification for Europe, SASO certification for the Middle East).

Aluminum Thickness: The Key to Strength and Longevity

The aluminum thickness of ACP directly affects its strength, impact resistance, flatness and service life. ACP consists of two aluminum sheets (front and back) and a core material, and the thickness of the aluminum sheets is usually measured in millimeters (mm). Here’s the selection guide:

0.20-0.30mm Aluminum Thickness:

• Suitable for indoor decoration, small signage, display panels and temporary structures. It is lightweight and low-cost but has poor impact resistance, so it is not suitable for outdoor or high-traffic areas.

0.35-0.40mm Aluminum Thickness:

• This is the most common thickness for general applications, including exterior cladding of low-rise buildings, interior walls, advertising billboards and signage. It balances durability and cost, and can withstand moderate wind pressure and impact.

0.50mm and Above Aluminum Thickness:

• Suitable for high-rise buildings, exterior curtain walls, large-scale advertising structures and areas with harsh environments (such as coastal areas with strong wind and corrosion). It has excellent strength, impact resistance and flatness, but the cost is higher. For projects in the Middle East or Southeast Asia with strong sunlight and wind, 0.50mm aluminum thickness is highly recommended.

Note: The total thickness of ACP (aluminum sheets + core) is usually 3mm, 4mm or 5mm. For example, a 4mm ACP with 0.40mm aluminum sheets is a popular choice for most exterior decoration projects.

Core Structure: Performance Starts from the Inside

The structure of ACP is determined by its core material, which affects fire resistance, weight, sound insulation and cost. There are three main types of core materials, each with distinct characteristics:

PE Core (Polyethylene Core):

• This is the most common core material, divided into flame-retardant PE (for B1 grade) and non-flame-retardant PE (for B3 grade). It is lightweight, low-cost, has good toughness and is suitable for most indoor and outdoor decoration projects (except high-rise public buildings). PE core ACP is the most cost-effective option for general use.

Mineral Core (Non-combustible Core):

• This core material is made of mineral fiber or cement, which is non-combustible and used for A2 grade ACP. It has excellent fire resistance, sound insulation and heat insulation, but is heavier and more expensive than PE core. It is ideal for high-rise buildings, public facilities and projects with strict fire safety requirements.

PVC Core:

• PVC core ACP has good waterproof performance and is suitable for wet environments (such as bathrooms, kitchens and outdoor areas with high humidity). However, it has poor fire resistance and is not recommended for public buildings or high-rise structures. It is mainly used for indoor decoration in wet areas.

Tip: For exterior cladding, choose PE core (B1 grade) or mineral core (A2 grade) based on fire safety requirements. For indoor wet areas, PVC core is a good choice, while non-flame-retardant PE core is only suitable for non-public indoor decoration.

ACP Coating Types: Durability Meets Design

The coating of ACP protects the aluminum surface from corrosion, UV radiation and fading, while enhancing its aesthetic appeal. The choice of coating depends on the usage environment (indoor/outdoor), aesthetic requirements and durability needs. Common coating types include:

PVDF Coating (Polyvinylidene Fluoride):

• This is the highest-quality coating for ACP, with excellent UV resistance, anti-fading, anti-corrosion and weather resistance. It can withstand harsh outdoor environments (such as strong sunlight, rain, salt spray) and has a service life of 15-20 years. It is suitable for exterior cladding of high-rise buildings, coastal areas and projects with high aesthetic requirements. PVDF coating is available in a variety of colors and finishes (glossy, matte, metallic).

FEVE Coating:

• Similar to PVDF coating in performance, FEVE coating has good weather resistance and anti-corrosion, but is more cost-effective. It is suitable for exterior cladding of low-rise and mid-rise buildings, and has a service life of 10-15 years. It is a popular choice for projects that require high durability but have budget constraints.

Polyester Coating:

• This is a common and cost-effective coating, suitable for indoor decoration and outdoor projects with moderate environmental requirements. It has good adhesion and aesthetic appeal but poor UV resistance and weather resistance, so it is not recommended for long-term outdoor use (easy to fade and peel). It is ideal for interior walls, signage and display panels.

Wood Grain/Stone Grain Coating:

• This is a decorative coating that imitates the texture of wood or stone, suitable for interior decoration (such as shopping malls, hotels, homes) to create a natural and elegant atmosphere. It is usually a polyester or PVDF coating with a special texture, and should be chosen based on the desired aesthetic effect.

✅ Final Recommendations for Selection

To sum up, choosing the right ACP requires integrating your project’s fire safety requirements, usage environment, budget and aesthetic needs. Here are some practical recommendations:

1. For high-rise public buildings (hospitals, airports, schools): Choose A2 grade (mineral core) ACP with 0.50mm+ aluminum thickness and PVDF coating.

2. For low-rise exterior cladding and general advertising signage: Choose B1 grade (flame-retardant PE core) ACP with 0.35-0.40mm aluminum thickness and FEVE or PVDF coating.

3. For indoor decoration (walls, partitions, display stands): Choose B1/B3 grade (PE core) ACP with 0.20-0.30mm aluminum thickness and polyester or wood grain/stone grain coating.

4. For coastal or harsh outdoor environments: Choose PVDF coating and 0.40mm+ aluminum thickness to ensure corrosion resistance and durability.

Always choose ACP from reputable manufacturers with complete certifications (CE, ASTM, SASO, etc.), and ask for sample testing to verify the quality of fire rating, aluminum thickness, structure and coating. A well-chosen ACP will not only ensure the safety and durability of your project but also reduce maintenance costs in the long run.