Industrial Pass Box
A pass box in a cleanroom is a specialized device used to transfer materials between two areas, typically between a cleanroom and a non-cleanroom or between cleanrooms of different cleanliness levels, while minimizing contamination. It acts as an airlock to maintain the cleanroom's sterile environment by preventing direct airflow and reducing personnel movement. Here’s a concise overview:
Key Features of a Pass Box:
- Interlocked Doors: Equipped with two doors (one on each side) that are mechanically or electronically interlocked, ensuring only one door can be open at a time to prevent cross-contamination.
- Construction: Typically made of stainless steel (e.g., SUS 304) for durability and ease of cleaning.
Types:
Static Pass Box: Used for transfers between areas of similar cleanliness levels (e.g., two cleanrooms). It lacks ventilation and relies on UV light and interlocks for contamination control.
Dynamic Pass Box: Used for transfers between areas of different cleanliness levels (e.g., non-cleanroom to cleanroom). It includes HEPA filters, a motor blower, and sometimes a differential pressure gauge to maintain air quality.
Functions:
- Contamination Control: Prevents airborne contaminants from entering the cleanroom by minimizing door openings and personnel traffic.
- Airflow Stability: Maintains stable air pressure and airflow within the cleanroom.
- Efficiency: Simplifies material transfer, reducing the need for gowning/ungowning procedures.
Applications:
- Pharmaceuticals: Transferring materials between compounding and filling areas.
- Electronics: Moving components between assembly and testing areas.
- Healthcare: Transferring sterile supplies between operating rooms and sterile processing.
- Food Processing: Moving products between preparation and packaging areas.
Working Principle:
- Materials are placed in the pass box through one door.
- The door is closed, and UV light may be activated to sterilize the items.
- In dynamic pass boxes, HEPA-filtered air removes dust particles.
- The opposite door is opened to retrieve the materials, ensuring no direct connection between the two areas.
Benefits:
- Reduces contamination risks.
- Saves time by streamlining material transfer.
- Enhances cleanroom hygiene with features like UV sterilization and HEPA filtration.
