Airtight doors are special doors designed for environments requiring high levels of airtightness. Their core objectives are to block air convection, prevent the spread of contaminants, and maintain a stable indoor environment.
Basic Structural Components
Door Frame and Door Leaf: Typically made of 304 or 316L stainless steel, high-strength aluminum alloy, or galvanized steel. Some models are internally filled with aluminum honeycomb, rock wool, paper honeycomb, or aluminum honeycomb to enhance thermal insulation, soundproofing, and compression resistance.
Inflatable Sealing Strip: Embedded in the groove of the door leaf or frame, made of methyl vinyl silicone rubber or EPDM rubber, featuring acid resistance, heat resistance, and aging resistance. Once inflated, it expands to achieve a tight seal.
Drive System: Often uses brushless DC motors, supporting automatic opening and closing, operating smoothly with a long lifespan (up to over 1 million cycles).
Control System: Integrates foot switches, remote controls, safety sensors (anti-pinch), and emergency air release valves, supporting single door control or multi-door interlocking.
Key Structural Features
Sandwich Structure Door Panel: The middle is made of thermal insulation/soundproof core material, with metal panels on both sides, firmly bonded by lamination technology to enhance overall rigidity and sealing.
Recessed or Progressive Sealing Mechanism: Some doors sink when closed, pressing the bottom sealing strip against the floor; or use progressive pressing technology, where closer to the closed position, the sealing force increases, eliminating the need to cut grooves in the track, reducing noise and wear.
Rounded Corner Design: The four corners of the door frame and panel usually have R>150mm rounded corners, making cleaning easier and reducing sanitary dead corners.
Window Configuration: Mostly double-layer insulated tempered glass (thickness about 5–330mm), with some featuring radiation protection or antibacterial coatings.
Sealing Principle Classification
Inflatable Type: Achieves sealing through compressed air inflating the sealing strip, suitable for high-level biosafety laboratories (e.g., P3/P4).
Mechanical Pressing Type: Uses wedge sliders, tension devices, and other mechanical structures to press the sealing strip. Simple and durable structure, but slightly less airtight than the inflatable type.
Performance Advantages
Airtightness: Virtually no leakage, meeting high standards such as GJB2805B-2021.
Sound Insulation: Can reach over 30dB (meeting JIS 25/35 grade).
Thermal Insulation and Energy Saving: Low thermal conductivity, saving up to 50% of air conditioning energy.
Corrosion Resistance and Easy Cleaning: Stainless steel or coated surfaces can withstand disinfectants such as formaldehyde and hydrogen peroxide.