How To Manage The Media Vacuum; The Media Vacuum System - Oce Arizona 250 GT User Manual

How to Manage the Media Vacuum

The Media Vacuum System

Introduction
The Arizona 250 GT uses a low-flow, high-vacuum system with three pre-set zones
to secure rigid media for printing on the printer table. A fabricated aluminum overlay
sheet placed on the surface of the table creates the vacuum field. The overlay sheet
is pin-registered to the table. A rotary vane vacuum pump is used to evacuate the
chamber of air between the sheet and the table. Three air-feed ports connect the
chamber to the vacuum pump through a series of manually operated flow valves.
These valves are used to activate or shut down the different vacuum zones. In order
for the system to work effectively during printing all the circular pockets on the top
surface of the overlay sheet connected to an active vacuum chamber must be
covered. This creates a closed vacuum system. A bleed valve is provided to adjust
the level of vacuum, if so desired.
Vacuum Overlay Sheet
The vacuum overlay sheet is supported on the table by 0.5mm diameter formed
half-shear features. This produces a small gap between the sheet and the top of the
table for air to flow. Foam tape applied around the perimeter of the sheet provides an
edge seal. Additional foam tape within the perimeter is used to separate each of the
three vacuum zones. The 0.5mm diameter half-shear feature creates the equivalent
of a counter-bored hole or circular pocket on the top surface of the panel. Each of
these pockets is connected to the sealed underside of the panel by 1.5mm diameter
punched holes.
Default Vacuum Zones
There are two default vacuum zone configurations, one for Metric and one for
Imperial units. The default zones are set up for common media sizes, but can be
modified with additional foam tape. The next section has more information on how
to create custom zones
default Metric and Imperial zone configurations are shown below.
(see 'How to Create Custom Vacuum Zones' on page
The Media Vacuum System
75). The
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