The number of clean room certifications are vast and vary tremendously. ISO 14644 is the most used standard when looking at electronics and pharma manufacturing controlled environments. With this popularity, it has also undergone revisions within the past five years.
No matter the standard, each is divided into classes. The classes are rated from 1 to 9. The class identifies the maximum limit for particulate size and quantity per cubic meter of air. The chart below showcases the size and the quantity breakdown.
ISO 9 as you can see is the loosest standard. This standard is equivalent to air quality within a city environment. These environments can fit a multitude of manufacturing and are some of the easiest to achieve and abide by. The opposite end of the spectrum, ISO 1 is the strictest and hardest to maintain. There are three main factors when designing for a clean room. These are surfaces, airflow, and employee access.
When selecting surfaces that will be within the environment it is best to choose a surface that will hold up to the level of use as well as not be damaged by the cleaners or solvents being used to ensure the surface is clean. This should carry over into part fixturing and even machine materials of construction as well. This is not always easy and should be a design element to the process and environment.
Airflow within the room is what helps maintain the concentration levels of particulates. Generally, a clean room is positively pressurized to where the pressure within the room is higher than that outside of the room. This results in a positive air exchange, generally this is provided by the HVAC system. Having a system that does not recirculate the air from inside of the room and a substantial filtration system is key. Another type of airflow that can be found within these environments is a blowoff operation for the part or process. When installing a blowoff within a clean room environment it should be confirmed that the materials of construction are compatible with the environment and cleaning processes and that the airflow will not be introducing particulate into the environment which can result in contamination.
Lastly, employee access should be limited to those employees who are trained and necessary to be within the environment. Sometimes if an employee wears the wrong type of deodorant it can effect an entire environment. Even the wrong type of clothing or soap can alter the state of an environment, let alone using a blowoff incorrectly or bringing the incorrect cleaner inside the cleanroom. Access to these areas should be limited and individuals should be well trained to meet the demands of the clean room.
If you would like to discuss your production environment or blowoff application within a clean room, please contact us.