December 12, 2001 — MINNEAPOLIS, MN — Donaldson Company, Inc, a manufacturer of industrial filtration systems, has custom-engineered filtration technology that can reduce contaminant coming from the exterior of unopened mail. Donaldson’s High Efficiency Downdraft Bench is designed to enhance the air quality of mailrooms during the mail sorting and handling process.

The filtration bench is an extension of Donaldson’s existing Downdraft Bench filtration technology, currently used for industrial operations worldwide. The filtration bench addresses the current market need for enhanced air quality in the mail handling process. The bench incorporates both design and filtration technologies to meet this need.

First, the airflow within the bench has been optimized using the Fluent computer airflow design tool. The design minimizes “dead air” space in the bench where bacteria can collect and grow. Second, the bench uses two-stage filtration technology to capture and contain contaminants. The first-stage utilizes Powercore media with Ultra-Web II nanofiber technology. This is followed by a second-stage using HEPA filtration technology.

The Donaldson filtration bench is designed to be used during the mail sorting and handling process. Unopened mail is loaded onto the tabletop of the bench where it can be sorted and examined. The company claims loose contaminants are removed from the mail on the bench by the downdraft airflow. Contaminant is then trapped on either the Powercore or the HEPA filter. The filtration bench captures contaminant of 0.3 microns in diameter and larger onto the HEPA filter at 99.97 percent efficiency. The bench also has a bag-in, bag-out system for the removal and replacement of filters. This system encloses the filters in a plastic bag during both installation and removal and disposal.

The Donaldson filtration bench assists in the removal of contaminant only from the exterior of unopened mail. Contaminants contained inside unopened envelopes cannot be captured by the bench.