Despatch LCC1-87NV-2 - Manual (Page 16)

7
HEPA Filters
Absolute HEPA (High Efficiency Particulate Air) filters are used to limit particulate size
in the work chamber to 0.3 microns or less. The gentle entrance and exit air velocity to
and from the HEPA filter results in high efficiency and long life for the HEPA filters.
Definitions
HEPA - High Efficiency Particulate Air
Burn-Off - A process for getting rid of the
binder and D.O.P. contained in the filter
from the manufacturing and testing function.
D.O.P. - Dioctyl Phthalate - Aerosol particles of submicron size used in the testing
phase to spot defects or measure filter efficiency.
Binder - An organic substance that is used in the construction of the filter that gives
some structural strength to the media.
Packaging and Shipping
Packaging practice varies among the filter unit manufacturers. Normally units are
packaged in cardboard cartons with various approaches for internal strengthening and
impact-resistance of the container. The shipping carton normally is marked with a
vertical arrow and "This Side Up". A filter unit is placed in the carton so that the pleated
folds are vertical (running from top to bottom - not side to side).
Filters should be shipped, handled and stored with the pleats in the vertical position. If
shipped with the pleats in the horizontal position, the filter medium may break at the
adhesive line. If handled or stored with the pleats in the horizontal position the pleats
may sag.
Moreover, the filter unit should be installed with the pleats in the vertical position. When
installed in the horizontal position the pleats form shelves for the collection of entrapped
material. The accumulated weight of this material causes sagging and leads to an early
failure of the unit.
NOTE: Chamber temperature transitions must not
exceed 1.5 C/minute in order to maintain
class 100 chamber conditions. Optional
filter is available for transition rates up to 5
C/minute. Consult the factory.