Clean rooms is a controlled environment where products are manufactured. It is a room in which controlls the concentration of airborne particles to specified limits. Eliminating sub-micron airborne contamination is really a process of control. These contaminants generates by people, process, facilities and equipment. They must remove continually from the air. The level to which these particles need to remove depends upon the standards required. The most frequently used standard is the Federal Standard 209E. The 209E is a document that establishes standard classes of air cleanliness for airborne particulate levels in clean rooms and clean zones. Strict rules and procedures follows to prevent contamination of the product.
Clean rooms environment control
The only way to control contamination is to control the total environment. Air flow rates and direction, pressurization, temperature,humidity and specialized filtration all need to controls tightly. And the sources of these particles need to controlled or eliminated whenever possible. There is more to a clean room than air filters. Cleanrooms plans and manufactures using strict protocol and methods. They find frequently in electronics, pharmaceutical, biopharmaceutical, medical device industries and other critical manufacturing environments.
The number of particles in clean rooms
It only takes a quick monitor of the air in a clean room compared to a typical office building to see the difference. Typical office building air contains from 500,000 to 1,000,000 particles (0.5 microns or larger) per cubic foot of air. A Class 100 clean room designs to never allow more 16 than 100 particles (0.5 microns or larger) per cubic foot of air. Class 1000 and Class 10,000 clean rooms designs to limit particles to 1000 and 10,000 respectively.
The hazard of Particles in clean rooms
A human hair is about 75-100 microns in diameter. A particle 200 times smaller (0.5 micron) than the human hair can cause major disaster in a clean room. Contamination can lead to expensive downtime and increased production costs. In fact, the billion dollar NASA Hubble Space Telescope was damaged and did not perform as designed because of a particle smaller than 0.5 microns.
Once built a clean room it must maintains and cleans to the same high standards.