Print engine for double-sided printing

1. A print engine for double-sided printing comprises

a chassis;

a pair of substantially identical inkjet printhead assemblies mounted on the chassis opposite each other;

a pair of transfer rollers mounted on the chassis and positioned with respect to the printhead assemblies to permit an inkjet printing operation to be carried out on the transfer rollers, the transfer rollers defining a contact region through which a sheet of print media is fed to receive the print; and

a pair of cleaning stations operatively engaged with the transfer rollers to clean the transfer rollers subsequent to the print being transferred to the sheet.

2. A print engine as claimed in claim 1 , in which each printhead assembly includes an ink reservoir structure that defines a number of ink reservoirs corresponding with respective inks and a printhead mounted on the ink reservoir structure to receive ink.

3. A print engine as claimed in claim 2 , in which the ink reservoir structures are displaceable relative to the respective transfer rollers, displacement mechanisms being engaged with respective ink reservoir structures to displace the printheads into and out of an operative position with respect to the respective transfer rollers.

4. A print engine as claimed in claim 3 , in which a sealing arrangement is positioned on each ink reservoir structure to bound the printhead, the ink reservoir structures being displaceable towards the transfer rollers out of the operative positions so that the sealing arrangements bear against the transfer rollers, such that the printheads are enclosed.

5. A print engine as claimed in claim 1 , in which the cleaning stations include sponges that bear against respective rollers.

6. A print engine as claimed in claim 5 , in which the cleaning stations include rubber wipers that bear against respective rollers downstream of the sponges.

7. A print engine as claimed in claim 1 , in which each transfer roller is coated with titanium nitride.