Brother MFC9100C Service Manual page 24

(3) Head cap
Shown below is a head cap which prevents the nozzles of the print head from drying up when they
are not in use.
Upon completion of printing, the carriage travels to the right and moves the head cap provided on
the purge unit together. On the bottom of the head cap is a tab which is lead by the head cap
guide of the purge unit. Accordingly, the rightward movement brings the head cap up to the
position where the head cap comes into tight contact with the print head so as to cap the nozzles.
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