Application of microporous Insulation Board in Fire-resistant Elevator Shaft Door Systems

1.Introduction

In the design of buildings, effectively containing severe fires and mitigating their impact poses a complex challenge in fire protection technology. When a fire occurs in a high-rise building, it is crucial not only to confine the fire to a small space but also to prevent its spread, affecting other floors.

During a fire, the elevator shaft becomes a natural chimney, contributing to the "chimney effect" in high-rise buildings. These areas become powerful "chimneys," accelerating the spread of the fire through various pathways at a rapid pace. Maximizing the suppression of the "chimney effect" in the elevator shaft can prevent or delay the diffusion and spread of smoke and fire along the shaft, providing valuable time for both trapped individuals and firefighters. The installation of fire-resistant insulation doors in elevator door halls plays a significant role in achieving this effect. In simple terms, it involves adding a "heat-insulating fire door" to the elevator.

If such fire-resistant insulation doors are installed in the elevator door halls of high-rise buildings, it will significantly delay the spread of fire through the shaft during a fire. This is beneficial in isolating trapped individuals from fire, heat, and smoke, allowing for more time for evacuation and the rescue of trapped individuals. Therefore, fire-resistant elevator doors are of paramount importance in protecting lives and preventing the spread of fires.

2.Requirements and International Standards for Fire-resistant Elevator Insulation Doors

Fire is the result of combustible materials undergoing a chemical reaction with oxygen, producing flames, heat, and smoke. In fire prevention, it is essential to address all three aspects. Worldwide, building components related to fire protection, such as door testing, need to reflect and meet these requirements, with testing principles and criteria closely aligned. The product to be tested is clamped in a specialized furnace, exposed to controlled fire for a predetermined time, and evaluated based on established standards. The primary evaluation focuses on insulation performance and integrity.

In European and American countries, there is a well-established performance testing standard system for elevator floor fire doors, primarily covered by DIN 1363-1 and DIN EN 1364-1, addressing fire resistance tests for non-load-bearing building components. The testing also aligns with the EN 81-58:2003 standard, published in January 2004, under European oversight.                         

3. Advantages of the Application of Nanoporous Insulation Board in Elevator Floor Door Systems

The developed MIP-950 insulation board by our company stands out as the ideal material for passive fire protection in elevator floor doors. Its application in fire-resistant insulation doors for elevators brings forth the following advantages, fully meeting relevant standards in various countries:

Non-flammability: MIP-950 insulation board is non-flammable and contains no combustible components. It does not decompose into any harmful substances to humans or the environment during a fire, making it a green, environmentally friendly, and safe thermal insulation material.

 Excellent Thermal Insulation: Due to its unique nanoporous structure and additives, the insulation board effectively reduces various forms of heat transfer, including convection, conduction, and radiation, to the lowest levels. As the temperature rises, it maintains a thermal conductivity coefficient even lower than static air, demonstrating outstanding thermal insulation performance. In contrast, traditional insulation materials such as silicate ceramic fibers and calcium silicate exhibit a rapid increase in thermal conductivity with rising temperatures, resulting in suboptimal or ineffective insulation performance (see Figure 2).

Lightweight and Thin: MIP-950 insulation board achieves the same thermal insulation effect as traditional insulation materials at only 1/4-1/6 of their thickness. For instance, at a flame temperature of 1160°C, a 25mm-thick insulation board maintains a backfire surface temperature of 128°C and a heat flux of 1643W/m2, well below the national standard of 140°C with a heat flux requirement of <15000W/m2. This allows for the thickness of fire-resistant insulation elevator doors to be on par with standard elevator floor doors, providing significant convenience for designers. In comparison, achieving a 140°C cold surface temperature with ceramic fiber requires a material thickness (door thickness) of over 100mm.

Integrity: The insulation board possesses sufficient strength and is encapsulated in non-flammable glass fiber cloth to ensure product cleanliness and prevent the release of dust. The material maintains its integrity during normal elevator operation. In the event of a major fire and exposure to high temperatures, the glass fiber coating may become brittle, shrink, or even melt, but the core material's integrity and thermal insulation properties remain unchanged.

4. Performance Parameters:

Maximum Operating Temperature: 1000℃

Density: Standard: 280±20kg/m³

Thermal Conductivity (YB/T4130-2005):

0.020W/Mk @ 200℃

0.026W/Mk @ 400℃

0.032W/Mk @ 600℃

0.038W/Mk @ 800℃

Shrinkage:≤3% (950℃ Full immersion)

≤2% (950℃ 24h Single side)

5. Typical Applications:

Nanoporous insulation materials applied in elevator floor doors currently lack unified standards. During the design process, factors such as the required fire resistance duration, the presence of reinforcements, and details of other components need to be considered. Weak points identified during flame testing should be reinforced for enhanced protection. According to some customer usage experiences: For meeting the EI-120 standard (120 minutes of integrity and thermal insulation), it is recommended to use nanoporous insulation boards with a thickness of 22-25mm.

For meeting the EI-60 standard (60 minutes of integrity and thermal insulation), it is recommended to use nanoporous insulation boards with a thickness of 16mm or above.

Considering the perfection of fire-resistant insulation: Generally, larger insulation board areas result in better insulation effects, as the heat from frontal flames is less likely to transfer through gaps between insulation boards to the back. An insulation board with an area equivalent to the door's surface area achieves the most ideal insulation effect. However, such insulation boards must be placed above the door reinforcements, and the door thickness cannot be minimized.

Another design approach involves avoiding the installation of insulation boards on reinforcements. Although the heat from flames can transfer to the back through reinforcements, it may still pass the test as temperature probes are not installed at the reinforcement positions. This design allows for the minimization of door thickness.

Processing dimensions of nanoporous insulation boards we can provide:

Length: ≤2800mm

Width: ≤750mm

Thickness: ≤50mm

Other product characteristics:

Core Material: Gray nanoporous insulation material

Coating: White glass fiber cloth; additional hydrophobic treatment is possible in special cases

Application Limitations:

Due to the general characteristics of the strength of nanoporous materials, it is advised to avoid designing overly long and thin insulation components. If insulation is necessary for extended portions, it is recommended to divide them into several sections for assembly.

For specific situations, please feel free to contact me: esther.zhang@firebirdref.com or Call me directly: +8615617725931