How to improve the fire resistance of aluminum corrugated composite board through coating or interlayer materials?
Publish Time: 2025-04-09
Aluminum corrugated composite board is widely used in building curtain walls, interior decoration, transportation and other fields due to its lightweight, high strength and easy processing. However, the insufficient fire resistance of traditional aluminum composite panels has always been a pain point in the industry, especially in high-rise buildings or public places, where fire safety standards are becoming increasingly stringent. In order to meet the needs of higher fire protection levels, the industry has significantly improved its flame retardant performance by optimizing coating technology and interlayer materials, while taking into account the economy and practicality of the materials.
In terms of coating technology, the selection and construction process of fire retardant coatings directly affect the fire resistance limit of composite boards. The current mainstream solutions include intumescent fire retardant coatings and inorganic ceramic coatings. Intumescent coatings will rapidly foam and carbonize at high temperatures to form a dense insulation layer, delaying the transfer of heat to the substrate. For example, a coating system with the addition of ammonium polyphosphate (APP) and pentaerythritol (PER) can trigger an expansion reaction above 300°C, effectively blocking the spread of flames. Inorganic ceramic coatings are based on silicate or aluminum phosphate, and form a stable ceramic barrier through high-temperature sintering. The temperature resistance can reach more than 1000℃, but the adhesion problem between the coating and the aluminum plate needs to be solved. In recent years, nano-modification technology has further improved the performance of the coating. For example, the addition of nano-silicon dioxide can enhance the mechanical strength and weather resistance of the coating, so that it can still maintain fireproof performance after long-term outdoor use.
The innovation of sandwich materials is another key to improving the fireproof performance of aluminum corrugated composite board. Traditional polyethylene (PE) core materials are flammable and release toxic gases when burned, and are gradually replaced by flame-retardant modified materials. For example, flame-retardant core materials filled with aluminum hydroxide (ATH) or magnesium hydroxide (MH) decompose and absorb heat when heated and release water vapor, dilute the combustible gas, and generate an aluminum oxide protective layer. This type of halogen-free flame retardant is outstanding in environmental protection, but the addition amount must reach more than 60% to pass the B1 fireproof standard, which may affect the flexibility and processability of the material. Another direction is to use mineral fiber or rock wool as the interlayer. This type of material is non-flammable and high temperature resistant, but the bonding strength problem between the core material and the aluminum plate needs to be solved. In addition, the honeycomb aluminum core structure is also used in special scenarios with high fire protection requirements because its enclosed air layer can delay heat conduction, but the cost is relatively high.
It is worth noting that the coordinated design of the coating and the interlayer can achieve better fire protection effect. For example, a layer of intumescent coating is compounded on the outside of the flame-retardant core material to form a "double protection": the coating first responds to the initial fire, and the core material continues to work at high temperatures. A European brand has used this type of design to make the composite board reach the A2 standard (non-combustible material level) of EN 13501-1. However, this solution needs to balance the material thickness and cost, and ensure that the coating does not crack and the core material does not absorb moisture.
In the future, the fire protection technology of aluminum corrugated composite board will develop towards multifunctional integration. For example, self-healing coatings can automatically repair cracks after minor damage to avoid degradation of fire resistance, while phase change material (PCM) interlayers can absorb a lot of heat in a fire and delay structural failure. In addition, with the restrictions on smoke toxicity in building regulations, the research and development of low-smoke halogen-free (LSZH) formulas will become a focus. However, these technologies still need to break through industrial bottlenecks, such as reducing the cost of nano-coatings or improving the molding efficiency of mineral core materials.
In short, through the innovation of coatings and interlayer materials, the fire resistance of aluminum corrugated composite board has been significantly improved, but performance, process and cost need to be weighed according to specific application scenarios. With the integration of new materials and interdisciplinary technologies, the next generation of composite boards may achieve greater breakthroughs in safety and sustainability.
