Laser-Textured Printhead Surfaces for Stable Droplet Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Print quality and speed of printheads are affected by factors such as drying or accumulation of print fluid at nozzle discharge orifices, leading to issues like clogging and inaccurate droplet ejection.
Innovation Solution
Applying a laser treatment on the surfaces of printheads to modify the surface texture, creating regions with altered wetting properties. This includes forming non-wetting regions around nozzle discharge orifices to prevent ink accumulation and wetting regions on internal surfaces to improve jetting accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If print fluid is discharged from nozzles at high speed, then printing speed is improved, but droplet breakup and accumulation around nozzles occur
Solution Approach 1:
The patent applies laser treatment to create localized surface texture modifications at specific locations (nozzle discharge surfaces and internal channel surfaces) to achieve different wetting properties where needed. The discharge surface is made non-wetting to prevent accumulation, while internal surfaces are made wetting to improve fluid flow, resolving the contradiction between high-speed printing and droplet stability
Solution Approach 2:
The patent changes the surface energy parameters of the printhead materials through laser treatment, transforming surfaces from their original wetting state to non-wetting state at the discharge orifices. This parameter change prevents capillary action that would cause ink accumulation and droplet breakup during high-speed operation
2Reliability
If print fluid accumulates around nozzle discharge orifices, then clogging occurs, but preventing accumulation requires surface modification
Solution Approach 1:
The patent replaces complex mechanical surface coating processes with laser treatment, which directly modifies the surface properties through energy input. This substitution maintains reliability by creating durable non-wetting surfaces while simplifying the manufacturing process compared to traditional multi-step coating and curing procedures
Solution Approach 2:
The patent changes the surface energy and roughness parameters through laser treatment, creating permanent non-wetting properties that prevent ink accumulation and clogging. This parameter modification achieves reliable nozzle operation without requiring complex assembly or additional functional components
3Object-generated harmful factors
If internal surfaces are made non-wetting, then ink accumulation is reduced, but jetting accuracy deteriorates
Solution Approach 1:
The patent applies different surface treatments to different locations: internal channel surfaces are made wetting to ensure complete fluid evacuation and prevent accumulation, while the discharge orifice surfaces are made non-wetting to prevent droplet breakup. This localized differentiation resolves the contradiction between preventing accumulation and maintaining jetting accuracy
Solution Approach 2:
The patent segments the printhead surface into distinct functional zones with different wetting properties - wetting zones in the fluid transport path and non-wetting zones at the discharge interface. This segmentation allows each zone to perform its specific function optimally, preventing accumulation while maintaining precise droplet ejection
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
The laser-altered surface textures reduce ink accumulation and drying at nozzle discharge orifices, preventing clogging and improving droplet ejection accuracy, thereby enhancing print quality and speed.
Implementation Method 1
a laser treatment on one or more surfaces of a printhead to improve printhead performance. The laser treatment modifies the material surface (i.e., the actual substrate material, such as stainless steel) to form a desired surface texture, which is referred to herein as a laser-altered surface texture
Implementation Method 2
a laser-altered surface texture may be formed on the discharge surface of a printhead to reduce the wettability of the discharge surface, such as around the nozzle discharge orifices. One technical benefit is accumulation and/or drying of print fluid is reduced or prevented around the nozzle discharge orifices
Implementation Method 3
a laser-altered surface texture may be formed on one or more internal surfaces of the printhead to increase the wettability of the internal surfaces, such as inner wall surfaces of the pressure chambers, an inner wall surface of the nozzles, etc. One technical benefit is jetting accuracy of the printhead may be improved
Data Source
AI summary
Laser treatment on surfaces of a printhead. In an embodiment, a printhead comprises an assembly of structural elements each comprising a metal substrate. The structural elements form a plurality of jetting channels and a manifold fluidly coupled to the jetting channels, and the jetting channels and the manifold have internal surfaces internal to the printhead configured to contact a print fluid. The printhead further comprises a laser-altered surface texture formed directly on one or more of the internal surfaces via a laser treatment to define one or more wetting regions on the one or more of the internal surfaces.