In today’s world of precision engineering and manufacturing, clean rooms have become indispensable. They find use in just about all fields, from pharmaceutical industries to electronic wafer-fabrication plants. What’s more crucial is that all equipment, services & clean room types must fully comply with FED STD 209E. This is the current ISO Standard which is slated to be replaced soon.
First, What are the Clean Rooms?
Clean rooms are virtually particle-free and contaminant-free environments used primarily for the manufacture of sensitive electronic parts and pharmaceuticals. Under FED STD 209E, services & clean room types are classified as Class 1, Class 10, Class 100, Class 1000, and Class 10000, with each class being defined by the permissible number of particles in every cubic foot of air.
In Class 1 clean room, for instance, 35 or fewer particles of size 0.1m in diameter are allowable per ft3 of air.
Design Tips for Curbing Active Particle Generation
Linear-position stages and other clean-room equipment comprising moving surfaces are often the primary causes of active particle generation. You can curb these active generators by:
- Swapping carbon black for unfilled urethanes or virgin Teflon in seals, especially on balls screws and bearing blocks. They offer better abrasion resistance and tend to produce significantly fewer particles.
- Using seals that have a narrow clearance between the shaft, rail, and seal lips. This way, the seals are more durable, produce fewer particles, and retain lubricant for longer.
- Eliminating use of seals altogether, if possible.
- Utilizing polythene/urethane lines or hoses and Teflon casings when designing external cable carriers.
- Designing all contacting surfaces to be extra smooth, and making sure there are no sharp edges.
- Using belt-sealing systems instead of metallic ones to minimize friction and particle generation
Design Tips for Containing Passive Generation
Particles can also be generated passively. The good news is that using anodized aluminum and stainless steel in the design for clean-room equipment can do the trick. They are not only sleek but also resist corrosion. More importantly, you should ensure that surfaces made with stainless steel and anodized aluminum are smooth and free from textured paint or cracks. When possible, limit the number of joints as much as possible.
Optimizing for Particle Removal
When designing your clean-room equipment, you must keep in mind the effects of ceiling-to-floor and laminar airflow. Oftentimes that means you’ve to set particle-producing components in areas that are as close to the exhaust ducts and floor as possible. Moreover, don’t position equipment over turbulence-causing and water-processing areas. The bottom line is that you’ve to keep all critical components off the path of laminar airflow.
These are just but a few handy tips that’ll help you design top-notch and ISO-compliant clean-room equipment. More crucially, however, you need to work with a turnkey supplier that offers best-in-class services & clean room types.