ULPA—When HEPA isn't clean enough
01/01/2001
by Laureen Belleville
 The Mac 10 family of fan filter units by Envirco comes with the option of ULPA filters for critical applications. |
Microscopic dust, bacteria, viruses and allergens beware. Filters used in air cleaning have become so precise that the most delicate wafer architecture can be exposed in cleanrooms without the slightest contamination from some very small particles.
ULPA (ultra-low penetration air) is a filtering efficiency specification for filters used in environments like pharmaceutical laboratories wherein the highest degree of clean air must be maintained. An upgrade to the standard HEPA (high-efficiency particulate air) filter, which filters particles down to 0.3 micron, an ULPA filter must retain all particles as small as 0.12 micron in size at an efficiency of 99.999 percent.
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The media for ULPA filters is typically made from sub-micron glass fibers formed into a high-density paper. Some filter systems incorporate corrugated aluminum "separators," which permit maximum usage of the media at minimum resistance. Other systems use graduated filtration, incorporating multiple layers of filter media to improve the performance and expected life span of the ULPA filter.
Certified ULPA filters are tested and marked for applications including electronics, pharmaceuticals, hospitals and nuclear and biological research, among others.
DISTRIBUTORS of ULPA FILTERS
The following companies distribute ULPA filters:
- Air Energy Systems, Montgomeryville, PA Tel: (215) 393-6810, Fax: (215) 393-6819, www.airenergysystems.com
- Clean Rooms West Inc., Tustin, CA, Tel: (714) 258-7700, Fax: (714) 258-7777, www.cleanroomswest.com
- Clean Zones LLC, Manalapan, NJ, Tel: (888) 399-2464, Fax: (732) 786-8994, www.cleanzones.com
- Contamination Control Products, Neptune City, NJ, Tel: (732) 869-3400, Fax: (732) 869- 2999, www.ccpcleanroom.com
- Filtech Inc., West Homestead, PA, Tel: (412) 461-1400, Fax: (412) 461-2846, www.filtechinc.com
- Liberty Industries, East Berlin, CT, Tel: (800) 828-5656, Fax: (860) 828-8879, www.liberty-ind.com
- Ultrapure Technology, Suwanee, GA, Tel: (800) 932-0309, Fax: (770) 932-0809, www.ultrapuretechnology.com