Flow-through Printhead Bypass Manifold Pressure Delta Reduction
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Solution Overview
Problem
Existing printheads face challenges in reducing pressure delta and pressure differences between nozzles, leading to inefficiencies in ink circulation and ejection processes.
Innovation Solution
A flow-through printhead design with bypass manifolds that fluidly couple supply and return manifolds, allowing print fluid to circulate through jetting channels and reduce pressure requirements, thereby minimizing pressure differences between inlet and outlet nozzles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a flow-through printhead design is used to enable ink circulation, then ink circulation efficiency is improved, but pressure delta requirements increase
Solution Approach 1:
The manifold is segmented into supply and return sections with a bypass channel connecting them, creating separate flow paths that allow ink to circulate while maintaining pressure balance across the printhead
Solution Approach 2:
The bypass channel acts as an intermediary pathway between the supply and return manifolds, facilitating pressure equalization and reducing the overall pressure delta required for ink circulation through the jetting channels
2Productivity
If ink flows through long jetting channels to enable circulation, then ink circulation is achieved, but pressure difference between inlet and outlet nozzles increases
Solution Approach 1:
The fluid passage system is segmented into multiple sections including supply manifold, jetting channels, return manifold, and bypass channel, allowing independent optimization of each section to balance flow distribution and minimize pressure differences
Solution Approach 2:
The bypass channel creates an alternative flow path that helps equalize pressure potential between the inlet and outlet regions of the printhead, reducing the pressure gradient that would otherwise develop across the long jetting channels
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design reduces the pressure delta required for printhead operation, enhancing the efficiency of ink circulation and ejection, leading to improved printing performance.
Implementation Method 1
The bypass manifold(s) helps reduce the pressure delta required for the printhead
Implementation Method 2
a piezoelectric actuator. A printhead also includes a drive circuit that controls when each individual jetting channel fires based on image data. To jet from a jetting channel, the drive circuit provides a jetting pulse to the actuator, which causes the actuator to deform a wall of the pressure chamber via the diaphragm
Data Source
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AI summary
Printheads for a jetting apparatus. In one embodiment, a printhead comprises a plurality of flow-through jetting channels each configured to jet a print fluid out of a nozzle. The printhead further includes a supply manifold fluidly coupled to the flow-through jetting channels, a return manifold fluidly coupled to the flow-through jetting channels, and one or more bypass manifolds fluidly coupled between the supply manifold and the return manifold.