Unique marriage ushers in alternative cleanroom space
07/01/2001
NEW MARKET PLAYER
Mark A. DeSorbo
TORONTO—The courtship was unique, and if there had been a personal ad leading up to the initial encounter, it may have sounded something like this: Outgoing HEPA filter-maker seeks open-minded portable shelter manufacturer for alternative cleanroom experiences without space commitment.
And the chemistry of this fateful union was indeed divine, for the marriage between shelter maker UniFold Shelters Ltd. and filter manufacturer Amaircare Corp. (Mississauga, Ontario) produced instant cleanrooms that range from 94 to 166 square feet, are capable of ISO Class 6 (Class 1000) cleanliness and can be purchased for as low as $4,000.
Love at first filtering
It all began on the floor of the Industrial Accident Prevention Association Show, held here in March.
Amaircare representatives were walking the floor where UniFold was displaying its polypropylene shelters, which are not only used by many police and fire departments, including the Oklahoma City Fire Department, but also by the U.S. Coast Guard, the United Nations and the Federal Emergency Management Agency for disaster relief and critical response.
"They approached us and said that there is a need in the market for companies to have the capability of a cleanroom without committing the permanent square footage," says Steve Ostrowski, vice president of UniFold Shelters.
Jim Woods, Amaircare's president, was already familiar with UniFold shelters, having purchased one to contain dust emitted from filling canisters with granulated carbon that is used in some of the filters the company makes.
"Granulated carbon, creates a lot of dust, and when you handle it, it's messy. It goes everywhere," says Woods. So, we went out and bought a shelter. We negatively pressurized it to keep the dirt inside the space. Then, we put in another small filtering unit to re-circulate the air to keep the employee inside safe from the dust. At the end of the day, there was hardly any dust in his facemask. It worked so well we thought it would work well as a cleanroom."
My place or yours?
Soon after paths had crossed the two companies put their heads together and determined that when Amaircare's HEPA filtration units and positive pressure are combined, particle concentration within the UniFold structure was quickly reduced.
 Unifold shelters, used mainly for disaster relief and critical response, can be cleanroom retrofitted. |
"We had given a presentation to the US Air Force, which is also planning to use the UniFold structure, and they asked us to test how much positive pressure it could take," Ostrowski says. "It can handle positive and negative pressures up to 0.005 pounds per square inch, or 1.5 inches of water. That's a significant amount of pressure."
Using a 94-square-foot UniFold shelter with a HEPA filter system from Amaircare, ambient particle concentration over 0.3 micron was approximately two million per cubic foot, not bad, Ostrowski points out, for a fabrication factory with the outside door wide open.
Initially, however, an interior HEPA filter was installed with no positive pressure, which brought counts down from two million to well below 50,000 particles per cubic foot. After confirming cleanliness without positive pressure, another HEPA filter unit was added where air was drawn from the outside, blowing filtered air into the shelter.
"We got below 1000 without any problem," says Woods, adding that particle concentrations fell below 300 per cubic foot within 20 minutes of setting up the structure.
Together forever?
Ostrowski says UniFold shelters offer the convenience of portability. "You can pull it out, set it up, get it operating for a particular production run and when the run is over, you can knock it down and hang the shelter on the wall. When folded, it's the same size as a king-size mattress," he adds.
In addition to the 94-square-foot unit, UniFold offers 132- and 166-square-foot shelters. When folded, Ostrowski says any one of the shelters with two filtration units can be stored within a six-square-foot space. UniFold shelters, he adds, can be outfitted with lighting, but the white roofs allow light to penetrate.
"This means you can maintain a perfectly lit, clean interior without lights or you can illuminate it from the outside using quartz flood lights," Ostrowski says.
The shelters are made completely of polypropylene, and they are held together with aluminum pop-rivets.
As for the filtration units, Amaircare manufactures several different units that range in price from $500 to $5,000, and can move and filter 20 to 1200 cfm.
Amaircare's Airwash filters are packaged with UniFold structure. Airwash filters are self-contained and can move up to 300 cfm.
"They can plug into a 110 or 220 line. The motors are sealed and contain particles. They have backward-curved air fans for air delivery. There is a special seal technology within the HEPA filters, which have metal end caps that allow the filter to screw into place," Woods says.
As far as uses go, Woods says a UniFold structure outfitted with Amaircare filtration systems would be ideal for curing clear coat applications or protective coatings, mixing or grinding compounds. "You can set up a theater within a major manufacturing complex, a box-within-a-box concept," he says.