How to Select the Right Airlocks?
Cleanroom airlocks are vital sealing systems in pharmaceutical manufacturing. Utilizing HVAC-controlled pressure differentials, they create an enclosed, pressurized space between external environments and cleanroom or between clean zones of different cleanliness levels. This invisible barrier is indispensable for preventing external contamination and internal cross-contamination, thereby ensuring product integrity and process stability.
Selecting the correct airlock type is a critical yet often underestimated decision. Although the hardware may seem straightforward, an inappropriate choice can compromise the entire controlled environment, leading to significant operational and financial risk.
With over a decade of experience as a cleanroom manufacturer, KINROM’s technical team regularly assists clients in navigating this exact challenge. This article consolidates our expertise to provide clear, actionable guidance for your airlock selection process.
Three Common Types of Airlocks
Based on differences in airflow direction and pressure, airlocks can be categorized into three main types: Cascade, Bubble, Sink, so we will explain the working principle, advantages, and application scenarios for each type.
1. Cascade Airlock
The cascade airlock is defined by its sequential pressure gradient. It features two interlocked doors, with the first opening to a lower-cleanliness area (e.g., a corridor) and the second to a higher-cleanliness zone (e.g., the cleanroom). The space between the doors acts as a buffer where air pressure is maintained at an intermediate level—higher than the exterior but lower than the cleanroom. This creates a directional airflow from the cleanroom outward, ensuring contaminants cannot migrate against the pressure cascade into the higher-classification area.
Advantage:
1. It provides reliable, unidirectional protection by maintaining a constant outward airflow from the cleaner zone.
2. Its simple design makes it cost-effective to install, operate, and maintain compared to other types.
Application:
Suitable for high-cleanliness areas requiring strict airflow control and cross-contamination prevention, such as tablet manufacturing lines, sterile formulation production lines.
2. Bubble Airlock
The bubble airlock maintains a higher pressure inside the air lock chamber compared to both adjacent areas. This creates a “bubble” of positive pressure that pushes air outward through any leaks, preventing contaminants from either side from entering the airlock itself. When personnel or materials pass through, the overpressure helps contain any particles generated during the transition.
Advantage:
Offers good protection for both sides and is effective for material transfer or areas where containment is needed.
Application:
It is the preferred choice for handling potent compounds or in sterile processing areas where bidirectional isolation is required.
3. Sink Airlock
The sink airlock maintains a lower pressure inside the airlock chamber compared to both adjacent areas. This creates a negative pressure “sink,” drawing air in from both sides. Any airborne contaminants generated during entry or exit are pulled into the airlock and exhausted, preventing them from escaping into the critical environments on either side.
Advantage:
Effectively contains contaminants within the airlock, protecting both the cleanroom and the external environment from hazardous particles or substances originating inside the airlock.
Application:
Essential for areas handling toxic, hazardous, or highly potent substances, ensuring they do not escape into surrounding corridors or labs.
Need More Information About Airlocks?
For more information or expert guidance on airlock selection, contact the KINROM technical team. As a fully experienced cleanroom manufacturer in China, we are ready to partner with you to build a successful, compliant cleanroom.
