Holding Up to Workloads in Classified Space

Choice of cleanroom casework, or furniture, is one of the most important decisions made when setting up classified space. Cabinets and associated doors, hinges, handles, panels, benchtops, shelving, and vertical/horizontal surfaces must be compatible with the application and the cleanroom’s classification by Federal Standard 209E for airborne particulate cleanliness. Surfaces must be as easily cleaned as walls and floors, emit no particulate contaminants, and above all resist exposure to liquids and solids processed inside the room. Since the purpose of a clean room is to protect the environment from hazardous materials or sensitive materials from the environment and humans, or both, clean room casework must fulfill those missions and be environmentally “invisible.”

Most cleanroom casework today is made from coated steel, stainless steel, and polypropylene. Polypropylene casework has been around for years, remaining a niche product due to its high cost, but Terry Thompson, polypropylene sales manager at NuAire (Plymouth, MN) says polypropylene is the material of choice for clean rooms that use corrosive acids or chemicals or that experience high humidity.

Polypropylene is about 2.5 times as expensive as steel or wood casework and just slightly more expensive than stainless steel. As Thompson explains, “Polypropylene is made from a petroleum product, so we’re at the mercy of the oil markets. But more important, a polypropylene cabinet needs a lot of handling during manufacture—much more than stainless steel… Polypropylene edges are sharp and must be smoothed and de-burred, then welded together.”

Cleanroom casework is normally specified by whoever plans the room, which is either an architect or a company engineer. Owners increasingly ask for modular casework, Thompson explains, because it provides versatility and changeover capability when a clean room’s mission changes.

Outside design firms sometimes over specify for casework, Thompson says, to cover all contingencies. In one instance where polypropylene casework was designated, Thompson called the owner to confirm that the application called for it. “They didn’t realize how expensive it was and wound up ordering a less costly alternative that suited their needs just as capably. If you can get by with metal casework, that’s obviously the way to go.”

Hemco specializes in Class 1000 and Class 10,000 clean room furnishings and installations, a niche that Campbell describes as “clean labs” to distinguish them from higherclass semiconductor processing suites. Hemco has done Class 100 installations, but usually as subareas of Class 1000 rooms. Within that marketplace the company sells casework fashioned from welded steel coated with an epoxy powder coat finish. These structures are fabricated as easily as stainless steel but have much higher resistance to acids and moisture. They are also available for about one-third the cost of polypropylene and stainless.

7000 Silver Series Seating

• Certified for Class 10 cleanrooms; Meets ANSI/BIFMA Standards
• Features heavy-duty chrome-plated back bar and spring-loaded hinge assembly
• Features easy-to-use pneumatic seat height adjustment and fully adjustable contoured back
• Includes sturdy five-legged polished aluminum base with standard glides or optional casters

BEVCO
www.bevco.com

InterMetro Clean Room Tables

• Features an electropolished stainless steel work surface that eliminates dust accumulation
• Bottom shelf and frame are adjustable in two-inch increments
• Support structure virtually eliminates “drumming”
• Available with a bottom shelf, H-frame or 3-sided tubular frame

Terra Universal
www.terrauniversal.com

Series 19 Dessicator Cabinets

• Can be purged to create a controlled environment for long-term storage
• Constructed with a heavy-gauge stainless steel outside shell and a stainless steel divider between each compartment
• Also available in polypropylene

Clean Air Products
www.cleanairproducts.com

Airegard 301 Horizontal Laminar Flow Cabinet

• Features a HEPEX™ Zero-Leak airflow system for consistent airflow and HEPA filter loading
• Features a work surface splash-back to protect the HEPA filter
• Includes a Minihellic® pressure gauge, fluorescent lighting and an adjustable motor speed controller
• Can be customized with UV lamps, taller filters, wider work surfaces and stainless steel work surfaces

NuAire
www.nuaire.com