 |
Technical
Service Bulletin 02-2
|
Filtration Media
The
purpose of filtration is contamination control. Contamination control
is the process of achieving a balance between the sources of contamination
and the ability of a system to tolerate contamination. The ultimate goal
is to balance filtration performance with the desired cleanliness level.
The
media in a filter is the physical mechanism used for contamination control.
Media construction and filter configuration are used to determine the
filter's efficiency for particle removal, it's contaminant capacity and
the pressure drop, or resistance to flow, through the filter. By working
with these variables - efficiency, capacity, pressure drop - the filter's
performance level can be determined.
With
filter media being so critical to contamination control, what is available
to construct media from? The options are virtually limitless. They range
from mesh screens to depth style media such as threads or chopped paper
to 100% natural cellulose to 100% man-made microfibers to almost any conceivable
combination in between.
With
so many media choices, how does an engine, system or filter manufacturer
choose which media to use? While keeping in mind the purpose of filtration
is contamination control, the manufacturer has to make a performance decision
regarding the physical size of contamination that can be tolerated by
the system.
Typically,
if only larger particles are to be removed, a very basic cellulose media
is used. As the size of contamination to be removed gets smaller and smaller,
the type of media changes from a more complex cellulose to blended media
where cellulose and man-made fibers are blended together in various configurations.
For the removal of extremely small contamination, media typically changes
from one dominated by cellulose to one made exclusively from various types
of man-made microfibers.
It
should be noted that filter manufacturers usually have between 50 and
75 different media grades at their disposal. Some of these are proprietary
to a particular manufacturer and some are more commonly used across the
entire industry. The reason for such a variety is not only the ability
to control a certain size of particle contamination but the fact that
media designed for oil filtration cannot be effectively used for air filtration
and air filtration media cannot be used for coolant filtration, etc.
Today's
automotive and heavy duty filtration needs are very different than those
of just 20 to 25 years ago. Media design, construction and availability
has changed to meet the performance needs of today's systems. Media research
and development continues to be very dynamic to insure the needs of future
systems are met.
For additional information, contact:
Filter Manufacturers
Council
P.O. Box 13966
Research Triangle Park, NC 27709-3966
Phone: 919/406-8817 Fax: 919/406-1306
www.filtercouncil.org
Administered by Motor & Equipment
Manufacturers Association
Created October 2002
Back to Top
Back to Technical Service Bulletins