how to control dust in clean room

Clean rooms are key environments for controlling pollution and maintaining air quality, especially in high-precision fields such as Semiconductors, pharmaceuticals, and food processing. The presence of dust not only affects production quality, but may also cause equipment failure and unqualified products. Therefore, controlling dust in clean rooms is the basic work to ensure production safety and quality.

Sources of dust in clean rooms

Control dust in modular clean room,the sources of dust in clean rooms mainly include external air, internal personnel, equipment, and raw materials. External air is an important source of dust, especially in the absence of an effective filtration system. According to the ISO 14644-1 standard, the number of air particles in A Clean Room should be controlled to not exceed the specified value per cubic meter, such as ISO level 5 requires no more than 3,520 particles larger than 0.5 microns.

1. External air pollution

Dust in the external air enters the clean room, often through ventilation systems, doors and windows, etc. To avoid this pollution, clean rooms are usually equipped with high-efficiency air filtration systems, such as HEPA (high-efficiency particulate Air Filter) or ULPA (ultra-high-efficiency particulate air filter).

2. Personnel and equipment contamination

The staff and equipment in the clean room are also the main sources of dust. The staff's clothing, skin and other materials may carry dust. Equipment may also generate tiny dust during operation, especially processing or cleaning equipment. The use of personal protective equipment such as dust-free clothing and gloves can effectively reduce this pollution.

3. Raw materials and products brought in

When raw materials and products enter the clean room from the outside, they may bring in dust or particles. Therefore, controlling the feeding and discharging processes and using clean packaging during transportation can effectively reduce the introduction of external pollutants.

Clean room air filtration and circulation system

Control dust in clean room,the air filtration system is an important means to control dust in the clean room. Efficient air filtration can not only remove most particles, but also ensure that the airflow direction, pressure, temperature and humidity in the clean room meet the standards.

1. HEPA and ULPA filters

HEPA filters can capture more than 99.97% of particles larger than 0.3 microns, while ULPA filters are more efficient and can capture 99.999% of particles. According to iso 14644-1, the number and size of particles in the air of a clean room must be strictly controlled. For example, the number of particles larger than 0.5 microns in the air of an ISO 5 clean room should not exceed 3,520.

2. Air flow and pressure difference

The air flow design in a clean room should ensure continuous air flow, prevent dead corners and air flow turbulence, and reduce dust accumulation. According to ISO 14644-4, a certain air pressure difference should be maintained in the clean room to ensure that air flows from the clean area to the contaminated area.

3. Air exchange rate and purification effect

The air exchange rate (Air Changes per Hour, ACH) of a modular cleanroom is also an important factor affecting air quality. Efficient air circulation can remove particles in the air in a timely manner. iso 14644-4 recommends that areas with higher cleanliness (such as ISO 5) should achieve at least 20 air exchanges per hour.

Cleaning and maintenance of clean rooms

Control dust in clean room,in addition to the control of the air filtration system, the cleaning and maintenance of the clean room are equally important. Regular cleaning and maintenance can reduce dust accumulation and bacterial growth, ensuring a clean environment.

1. Equipment and surface cleaning

Equipment and work surfaces should be cleaned with dust-free, low-volatile detergents. Regular inspection and cleaning of vents, filters and other equipment is the basis for maintaining clean room air quality. For example, filters should be replaced every 6 months or once a year depending on usage to maintain optimal filtration.

2. Staff training and specifications

Staff in clean rooms should receive rigorous training to learn correct cleaning operations and pollution control knowledge to avoid human-caused pollution. iso 14644-2 mentions that employees should wear dust-free clothing, gloves and masks, and perform proper cleaning and disinfection before entering the clean room.

Clean room monitoring and control technology

Control dust in clean room,the monitoring system in the clean room is the "eye" to ensure air quality. Real-time monitoring can help managers detect dust pollution sources in a timely manner and take prompt measures.

1. Particle counters and air quality monitoring

Clean rooms should be equipped with particle counters to regularly measure the number and size of particles in the air. The ISO 14644-1 standard clearly specifies the requirements for particle counts in clean rooms of different grades. Real-time monitoring of particle counts helps to identify pollution sources in a timely manner and take necessary control measures.

2. Temperature and humidity control and monitoring

Temperature and humidity are also important factors in clean room dust control. Too high or too low humidity may affect the precipitation of particles or charge accumulation in the clean room. ISO 14644-1 requires that the temperature and humidity in the clean room must meet the regulations to avoid the generation or suspension of dust.

3. Automated control system

Modern clean rooms have generally adopted automated control systems to adjust parameters such as air filtration, temperature and humidity, and pressure difference in real time to ensure stable air quality. Through the automated system, managers can efficiently control the environment of the clean room and reduce the possibility of human operational errors.

Controlling dust in the clean room is an important part of ensuring product quality and improving production efficiency. From air filtration to cleaning and maintenance, to monitoring and control, every detail is directly related to the working effect and production safety of the clean room. By continuously optimizing technology, processes and management, the dust control level of clean rooms will continue to improve to meet increasingly stringent industry requirements.