Metal sandwich panels are lightweight building materials composed of two metal face sheets (typically color-coated steel or aluminum) and an insulating core material bonded together with high-strength adhesives. This structure not only provides excellent thermal insulation but also offers high mechanical strength and ease of installation, making them widely used in industrial, commercial, and specialized buildings. Depending on the type of core material and intended application, metal sandwich panels can be categorized into various types to meet different requirements for fire resistance, thermal insulation, soundproofing, and cleanliness.

1. Classification by Core Material and Characteristics

1.1 PUR/PIR Sandwich Panels
With polyurethane (PUR) or polyisocyanurate (PIR) as the core material, these panels offer the best thermal insulation performance among sandwich panels. Their low thermal conductivity (typically 0.022-0.024 W/m·K) effectively reduces energy consumption. PIR cores provide better fire resistance than PUR, achieving up to a B1 fire rating (flame-retardant). These panels are lightweight and high-strength, making them suitable for applications with strict thermal insulation requirements, such as cold room facilities and temperature-controlled workshops.

1.2 Rock Wool Sandwich Panels
The core material is rock wool, made from molten natural rock fibers. Their greatest advantage is exceptional fire resistance, meeting the A-grade non-combustible standard. They also offer good soundproofing and thermal insulation properties but are relatively heavier due to their higher density. These panels are ideal for fire-prone environments, such as chemical plants, stadiums, and high-rise buildings.

1.3 EPS Sandwich Panels
With expanded polystyrene (EPS) as the core material, these panels are the lightest and most economical option. They provide good thermal insulation but have a lower fire rating (typically B2 combustible). They are suitable for temporary structures, warehouses, and general industrial buildings where fire safety requirements are not stringent.

Comparison of the Three:

• Thermal Insulation: PUR/PIR > EPS > Rock Wool

• Fire Resistance: Rock Wool (A-grade) > PUR/PIR (B1-grade) > EPS (B2-grade)

• Cost-Effectiveness: EPS > Rock Wool > PUR/PIR

• Applications: Choose rock wool for high-temperature or fire-prone environments; PUR/PIR for low-temperature insulation; EPS for budget-conscious projects with no fire safety concerns.

2. Classification by Application and Characteristics

2.1 Standard Sandwich Panels
Primarily used for walls and roofs of industrial plants and warehouses, these panels focus on basic thermal insulation and structural support. The core material can be selected based on specific needs.

2.2 Cold Room Panels
Designed for low-temperature environments (such as cold room and cold chain workshops), these panels typically use PUR/PIR core materials to ensure optimal insulation. Special sealing structures are used along the edges to prevent cold bridges.

Why is PUR/PIR the best core material choice for cold room panels? >>

2.3 Cleanroom Panels
Used in environments with high cleanliness requirements, such as hospitals, laboratories, and food processing plants. The surface is made of stainless steel or antibacterial coating, with sealed joints to prevent dust accumulation and bacterial growth. The core material can be rock wool or glass magnesium board to meet both fire resistance and cleanliness requirements.

2.4 Metal Roof Sandwich Panels
Designed specifically for roofing systems, these panels often feature high-wave profiles to enhance drainage and load-bearing capacity. The core material must possess long-term stability, with PUR/PIR and rock wool being common choices.

3. Key User Concerns

1. Fire Resistance: Select core materials based on building safety regulations, such as A-grade rock wool for high-risk areas and B1-grade PIR for general energy-efficient buildings.

2. Core Material Type: A critical factor determining thermal insulation, soundproofing, and structural performance. Selection should balance cost and requirements.

3. Sound Insulation: Rock wool cores offer the best sound absorption, making them suitable for noise-sensitive environments.

4. Surface Material: Color-coated steel provides good weather resistance; stainless steel or antibacterial coatings are used in clean environments; PVDF coatings are ideal for highly corrosive environments.

In summary, the selection of metal sandwich panels requires a balance of practical application scenarios, safety regulations, and budget constraints. Whether for ultra-insulated cold storage, fire-safe industrial plants, or sterile cleanrooms, there is a tailored panel solution available.