Do you have an application such as inspection of parts or assembly of optics that calls for a clean work environment free from airborne particulate matter? Laminar flow workstations are commonly used for Class 100 (ISO 5) applications that need a level of cleanliness corresponding to less than 100 particles of diameter greater than 0.5 micrometers per cubic foot of air. This type of clean environment is also ideal for the medical, pharmaceutical, electronics, food and industrial sectors for sterile manipulations, assembly of miniature mechanisms, production of optical components.
Laminar Airflow Workstations
Laminar flow workstations provide a source of clean filtered air that flows smoothly over the work area and then out, keeping the working area at the rated cleanliness level. These workstations come in a range of sizes from 24″ wide and 24″ high to as much as 96″ wide by 37″ high, and can be moved through standard-width doorways. The workstations will have:
- a flow hood,
- both electrostatic and HEPA 99.99% air filters,
- micro-controlled low-speed air blowers,
- integral lighting over the work area,
- electrical outlets for equipment,
- surfaces of stainless steel for easy cleaning, or polypropylene to avoid any possible contamination from rust.
The working area is enclosed at the sides to ensure guided airflow and to prevent the possibility of contaminating particles mixing in from the outside. The low blower speed prolongs the fan’s lifetime and also provides a quieter environment for the operator, with noise levels around 65 DBA. Electrical outlets, cable trays and tool drawers are integrated into a complete workstation for a broad spectrum of applications.
These are the basic types of laminar airflow workstations for clean environment applications.
Horizontal Flow Workstation
In a horizontal flow bench, the room air is pulled in from an opening on top of thelaminar flow hoodor below the work area platform and then prefiltered electrostatically. The air then moves to the rear of the bench and exits through HEPA filters that span the back of the workstation into the working area, after which the ultra-clean Class 100 air exits towards the front of the workstation, and past the operator. The laminar air flow is monitored, and any filter obstruction is reported to the operator. This horizontal flow bench design is intended for product protection.
Such a flow hood could also make an excellent tissue culture hood. Other clean bench applications could be for:
- IV admixture preparation,
- drug compounding,
- plant cell culture,
- media preparation,
- pharmaceutical procedures,
- electronics assembly.
Vertical Flow Workstation
A vertical flow bench design also has the room air pulled in from the top of the laminar flow hood where it is prefiltered electrostatically. In this case, the air then is pulled below through HEPA filters and flowed downward onto the working surface, exiting past the operator at the front. The intended use for this design is in applications that require clean environments and pose no hazard to the operator.
Polymerase Chain Reaction Workstations
Some laminar flow workstations have specialized enclosures that reduce the risk of sample contamination while performing polymerase chain reaction experiments. The constant positive pressure HEPA filtered air prevents airborne contaminants from entering into the work zone. The workstations are equipped with a built-in shortwave UV lamp to effectively decontaminate the work area between amplifications. Safety interlocks prevent operators from being exposed to UV radiation. However, keep in mind that these are not biological safety cabinets. They are designed to provide process protection only from potential airborne contaminants found in the laboratory space.