Page 251 - Training 2019

INTRODUCTION:

Ink pumps are used to pump and circulated the ink into ink pans or chamber blade units. This is to
make sure that sufficient ink gets to the anilox roller or gravure cylinders. Apart from that the ink
provides the colour, it also acts like a lubricant between the anilox roller or gravure cylinder and the
doctor blade. Electrical Ink pumps are the most popular type of pump that was used and is still in
use today. As printing changed over the years so did the inks and machine speeds. The machines
became more sophisticated and the inks as well. With the changes that took place so too did it affect
the way we pump and circulated ink on the press. The electrical impeller pump agitates the ink and
mixes it well; however, it can cause foaming especially with some water based systems and is not
ideally suited to chamber blade units.

HISTORY:

All printers need to move printing ink from a bucket to an ink trough or chamber blade unit. The
purpose of this is to feed enough ink into the chamber blade unit that will fill the cells, lubricated the
anilox roller, doctor blade and to prevent the ceramic anilox roller from any scoring. The chamber
blade should be kept full to prevent this from happening. Then the cells of the anilox roller need to
be kept full for the correct amount of ink to be transferred to the substrate. If the ink is too aerated
or referred to as break down, it cannot fill the cells, and this will cause issues with poor lubrication
and not enough ink. As printing evolved so has the way in which ink is been pumped from ink
container to Chamber blade units

TYPE OF PUMPS:

Impeller Ink Pumps:
,

Impeller/centrifugal pumps can be electrical or air operated and mainly used on Gravure or coating
machines. They are low maintenance and can take a lot of abuse. When working with solvent
based inks the pumps need to be flame proof (special electric motor and plug or air operated).
They deliver a constant flow of ink that is uninterrupted. It’s easy to regulate the flow by
controlling the out let valve. A lot of Flexo printers use them as well but it’s not recommended for
chamber blade systems. The action of the impeller can cause foam, which in turn can cause
starvation in the chamber. Foam build up in the chamber blade unit can create bubbles to burst
that gets attached to the anilox rollers. This leads to waste been generated and wasted is loss of
production, time and money.

INK PUMP TRAINING MANUAL 2
Updated - 24 June 2019