Many ribbon blenders have the traditional U-Shaped Shell. The full open top allows for ease of access during cleaning. In a U-shaped shell, the cover arrangements include a flanged, filtered Bag Dump Work Station and an end cover. Ribbon blenders, which are mixing with a mixing tool tip speed > 1 m/s, must present the following characteristics:

• Clearance in between the tip of paddles and the mixer body must be large enough to avoid any contact of ribbon to housing
• The bearing seals must be pressurized
• During loading and discharge, the mixer speed must be such that the tip speed of the paddles is < 1 m/s