XJ128 and XJ128 Plus Printhead
XJ128 Guide to Operation
Xaar Document no: D031010302 Version A
Page 38
The primary ink filter should be a 5
ì
m replaceable filter that is used to deliver ink to the ink system
reservoir. Ink filtration should take place prior to the printhead ink reservoir, please refer to section
7.4 for ink filter positioning. See the appropriate Ink and Printhead User Guide documentation for
filter recommendations and materials compatibility.
7.3 Providing a negative pressure ink supply
The printhead acts like a pump and therefore is capable of pulling ink through it. A negative ink
supply pressure must be used with the printhead to stop ink flowing in an uncontrolled manner
through the printhead.
The influence of the non-wetting coating on the XJ128/200 and XJ128/360 printheads means that the
negative head for the ink supplied to the printhead differs to that when supplying ink to the
XJ128/200 Plus printhead. In general, the negative head of ink required supplying ink to the
XJ128/200 Plus printhead is greater than that required supplying ink to the standard printheads fitted
with a non-wetting coating. The negative pressure used with the printhead and the associated ink is
stated in the appropriate Ink and Printhead User Guide documentation.
A negative pressure ink supply can be provided in one of two ways.
7.3.1 Gravity fed negative pressure ink supply
The most common and most simple way to supply a negative pressure ink supply is to position the
ink reservoir below that of the printhead nozzles. The ink reservoir is open to atmospheric pressure.
The ink supply pressure can be easily changed by moving the ink supply reservoir, up or down,
relative to the printhead.
Figure 7.1
–
Gravity fed ink supply system
-ve head of ink
Open to
atmosphere