Web printing – Universal Laser Systems CLP-100NI-NPRT User Manual

Page 19

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19

WEB PRINTING

To eliminate this problem, if idler roller positions are
not adjustable, a slight undercut in the face of idler
roller “B” where the printed marks pass under the roll,
will prevent the wet marks from touching the face of
the idler. Generally the undercut in the idler roller
needs to be only .020" - .030" deep and slightly wider
than the printed marks as shown in Figure 33.

This section applies to the installation of the Non-Porous Conveyor Line Printers for printing on continuous web
materials such as plastic films, rubber sheeting, metals and other extruded materials.

Careful consideration should be given to selecting an appropriate area in the production line for installation of the
coder. Since the coders are friction driven by the moving web of material, a primary factor is to select an area
where the position of the web material is accurately controlled and preferably supported by an idler or guide roller
on the underneath side as shown in Figure 32.

The only real consideration with respect to the
attitude of the coder frame is that the 4 oz. res-
ervoir ink cartridge (when installed) should be
kept as near to a vertical position as possible
with the plastic ball pointing down. This will en-
sure proper ink feed from the 4 oz. cartridge to
the ink roll. When disposable Type MT Ink Rolls
are used on the coder, 4 oz. Reservoir Ink Car-
tridges are not used and therefore the coder can
be mounted in any convenient attitude. When
installing the coder, the print drum axle of the
coder should be in parallel alignment with the
idler roll and the print drum should contact the
web at the point where the web is tangent to the
idler roll and solidly supported. It is also impor-
tant that the distance “C” between idler roller “A”
and idler roller “B” should be adequate so that at
the maximum web speed, the ink will dry before
the printed marks contact idler roller “B”. If dis-
tance “C” is not adequate for the drying time of
the ink used, a ghost image transfer of the marks
may be overprinted on the web by idler roller “B”.

UNDERCUT

.020” - .030”

IDLER ROLL

WET IMPRINT

4 OZ.

RESERVOIR

INK CARTRIDGE

PRINT DRUM

IDLER ROLL A

IDLER ROLL B

WEB TRA

VEL

MOUNTING

COLUMN

C

15

o

FIGURE 32

FIGURE 33

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