In recent years, the global cleanroom industry has experienced rapid growth in both technology and market size, driven by high-end sectors such as precision machinery, semiconductors, aerospace, medical equipment, and pharmaceutical engineering. Today, cleanrooms are widely used across various industries, including scientific research, electronics, automotive manufacturing, food processing, and healthcare. Each sector has its own cleanroom design and technical standards, but the daily maintenance procedures remain largely consistent. This article serves as a practical guide for cleanroom users.

1. Cleanroom Equipment Management: Filters, Air Showers, and More

Cleanrooms rely on a variety of purification equipment, such as FFU high-efficiency filters, air showers, cleanroom doors/windows, and floors. Proper management of this equipment is essential to maintaining the required cleanliness levels.

1.1 High-Efficiency Filter Maintenance

Pre-filters and medium-efficiency filters are installed to prolong the lifespan of high-efficiency filters by capturing larger airborne particles. These filters should be inspected monthly to determine whether they have reached their final resistance level. Once the final resistance is reached, they must be either cleaned or replaced.

Typically, fresh air filters located outside the air handling unit (AHU) should be replaced weekly. Pre-filters inside the AHU should be replaced monthly, medium-efficiency filters quarterly, and nylon mesh filters inside return air columns monthly.

High-efficiency filters are critical components in cleanroom maintenance, designed to remove particles larger than 0.3μm and ensure air purity. The lifespan of these filters depends on the pressure differential and cleanliness requirements of the room but generally exceeds 8,000 hours. As terminal filters, high-efficiency filters must undergo regular leak testing to ensure a completely sealed system. They should be tested every six months and replaced once the final resistance is reached—typically twice the initial resistance, with pressure sensors installed before and after the filter.

1.2 Air Shower Guidelines

Air showers are essential for removing dust from personnel and materials before they enter a cleanroom. Acting as a barrier between clean and non-clean zones, air showers feature interlocking doors that prevent simultaneous opening. Users must adhere strictly to operational protocols: overloading is prohibited, and doors must not be forced open during the shower cycle. Air velocity should exceed 25 m/s for optimal performance.

Regularly clean the exterior surfaces of the air shower to maintain hygiene and monitor both air velocity and dust concentration at the nozzle exit. If the air velocity drops below 18 m/s or the filter resistance exceeds 300 Pa, replace the high-efficiency filter. Pre-filters should also be replaced after 700 hours of use.

2. Cleanroom Personnel Management and Workflow Guidelines

Appointing a dedicated cleanroom manager is crucial for overseeing personnel and workflow compliance. All staff must follow these best practices:

1. ​​Strict Entry Protocols​​: Follow the personal purification process—changing shoes, washing hands, changing clothes, and passing through an air shower. Limit the number of personnel and prohibit unauthorized access. Inside the cleanroom, adhere to dress codes: hair must be fully covered by caps, and protective clothing such as dust-free gowns must be worn.

2. ​​Minimize Contamination​​: Avoid actions that generate dust or involve excessive movement. Do not place items upstream of the work area or conduct unrelated tasks.

3. ​​Prohibit Non-Essential Items​​: Do not bring unnecessary or dust-generating items into the cleanroom.

4. ​​No Food or Smoking​​: Eating, drinking, and smoking are strictly prohibited in cleanroom areas.

   
   

   

3. Daily Cleanroom Cleaning and Maintenance Schedule

A consistent cleaning routine is vital for cleanroom maintenance. After daily operations, perform general cleaning. If cleaning is required before production, ensure the cleanroom system has completed its self-purification cycle.

• ​​Daily Cleaning​​: Floors, workbenches, and air showers.
• ​​Weekly Cleaning​​: Walls, ceilings, and doors/windows.
• ​​Monthly Cleaning​​: Return air columns.

To prevent cross-contamination, use dedicated cleaning tools for each cleanliness level. Prefer purified water for wiping; in special cases, alcohol-based solvents may be used.

If the cleanroom system is shut down for more than 24 hours (e.g., during holidays), run the system and allow at least 30 minutes of self-purification before resuming operations.

By adhering to these protocols and performing regular maintenance, you can ensure your cleanroom operates at peak efficiency and meets regulatory standards.