Coordination of Pressure and Temperature During Ink Phase Change

摘要

A print head assembly for an ink jet printer includes an ink flow path configured to allow passage of a phase-change ink. A pressure unit is fluidically coupled to the ink flow path to apply a pressure to the ink. The applied pressure is controlled by a control unit during a time that the ink in the ink flow path is undergoing a phase change. During the phase change, a portion of the ink in a first region of the ink flow path is in liquid phase and another portion of the ink in another region of the ink flow path is in solid phase. A constant or variable pressure can be applied at least to the liquid phase portion of the ink during a phase transition from a liquid phase to a solid phase or from a solid phase to a liquid phase.
A print head assembly for an ink jet printer thus comprises:
an ink flow path (510-520), the ink flow path configured to allow passage of a phase-change ink along the ink flow path;
a pressure unit (555) configured apply pressure to the ink; and
a control unit (550) configured to control the pressure applied to the ink and to coordinate the pressure applied to the ink with temperature of the ink during a time that the ink in the ink flow path is undergoing a phase change.