Air showers use jets of filtered air to clean particle contamination from personnel and equipment during entry into a cleanroom environment. Removal may include dust particles or other excess contaminants residing on the person. Sprayed air is designed to blow in multiple directions and can exceed velocities of 25 m/s in certain models.Electric Floor Clean Machine Driving Dust Cart KW-C48
Cleanroom Contamination
Contamination in the context of a cleanroom is a process that allows materials or surfaces to be soiled. Even small amounts of contamination that seem insignificant to the human eye can cause "killer defects." Killer defects being defects that cause catastrophic failure in a device or circuit. The two forms of surface contamination that cause killer defects to form in electrical circuits are particulates and film contaminants.Blow Molding Film Cleanroom
Particulates
Particulates are small, granular, solid objects such as dust or flakes. They are deposited on surfaces through dry deposition. Particulates as small as 0.3 microns are known to cause killer defects and are filtered out of the controlled environment.Multi User Stainless Steel Air Shower
Film Contaminants
Film contaminants are air-borne materials that collect on surfaces forming a thin coating. They can source from fumes, smoke, and the outgassing of soiled surfaces. Film contaminants as thin as 10 nm (nanometers) alter surface properties and may cause a killer defect to form in the chip or wafer.Industrial Rolling Shutter Garage Door
Function of an Air Shower
The entrance of personnel to the work area is the largest contributor to contamination in a cleanroom and air showers are designed to minimize the risk of contaminating the controlled environment. Air showers are self-contained units with interlocking doors, a HEPA filtration unit, blower, and a programmable logic controller (PLC) or other control unit.Ride-On Rotary Floor Scrubber Machine KW-X600J
Blowers
Air shower blower units are used to circulate high velocity airflow through the air nozzles, return vents, and HEPA filtration unit. The blower supplies a high velocity air flow that acts as a scrubbing agent, cleansing fully-suited personnel in their required PPE attire.Ride-On Rotary Floor Scrubber Machine KW-X1040J
HEPA Filters
High-efficiency particulate air (HEPA) filters and ultra-low particulate air (ULPA) filters are designed to screen particles larger than 0.3 µm. HEPA filters are 99.99% efficient in removing particles 0.3 µm and larger. ULPA filters are 99.9995% efficient in removing particles 0.12 µm and larger. When used with a pre-filter, HEPA filters and ULPA filters can last for several years in a cleanroom environment. Moreover, because airflow capacity decreases and static pressure increases over time, HEPA filters and ULPA filters can become more efficient as the filter loads.Hand-Push Unpowered Sweeping Machine KW-S40A
Programmable Logic Controllers (PLCs)
PLCs (programmable logic controllers) are the control hubs that are used to operate the air shower. They contain multiple inputs and outputs that use transistors and other circuitry to monitor, operate, and control the air shower. They are software programmable and are interfaced via standard computer interfaces, proprietary languages, and network options. They receive input from door interlocks, pressure sensors, flow sensors, and other feedback loops in order to operate the blower and control access to and from the cleanroom. Benefits of Air Showers And How Air Showers Are Used