Oleophobic Coating for Ink Jet Printhead Front Face
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Solution Overview
Problem
Current ink jet printhead front face coatings are prone to wetting, drooling, and flooding by ultra-violet gel ink and solid ink, leading to nozzle blockages and degraded print quality, and are not robust enough to withstand maintenance procedures like wiping.
Innovation Solution
A low adhesion surface coating comprising an oleophobic polymeric material with a sliding angle of less than 30° is applied to the printhead front face, allowing ink droplets to roll off without residue and maintaining its properties through multiple wiping cycles, thereby preventing contamination and enhancing print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current sputtered polytetrafluoroethylene coatings are applied to the printhead front face, then the coating provides some protection, but the ink still wets, drools, and floods the surface leading to nozzle blockages
Solution Approach 1:
The patent changes the surface energy parameters of the printhead front face by applying an oleophobic coating that specifically reduces adhesion to oil-based substances. This coating modifies the surface properties to create extreme oleophobicity, causing ink droplets to bead up and roll off rather than wet and adhere to the surface, thereby preventing contamination while maintaining coating integrity
Solution Approach 2:
The patent employs a composite coating system that combines oleophobic polymeric materials with specific surface treatments to create a multi-functional surface layer. This composite structure provides both the protective barrier function and the extreme oleophobic properties needed to prevent ink adhesion, overcoming the limitations of single-material polytetrafluoroethylene coatings
2Ease of repair
If the printhead front face is wiped during maintenance, then cleaning is achieved, but conventional coatings are damaged or removed reducing their effectiveness
Solution Approach 1:
The patent applies an oleophobic coating specifically designed to withstand the mechanical stress of wiping operations. The coating is formulated with enhanced adhesion properties and flexibility that allow it to absorb and dissipate the forces applied during maintenance wiping, preventing coating damage while maintaining its oleophobic functionality throughout the printhead's operational life
3Productivity
If the printhead operates at typical jetting temperatures (75°C for UV gel ink, 105°C for solid ink), then ink ejection is achieved, but the ink flows along the front face leaving residue films that interfere with jetting
Solution Approach 1:
The patent applies an oleophobic coating to the printhead front face before operation that preemptively prevents ink adhesion. The coating creates a low-energy surface that repels oil-based ink substances, causing jetted ink to bead up and roll off the surface rather than spread and form residue films, thereby eliminating the harmful effect of front face contamination while maintaining normal ink ejection functionality
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 low adhesion coating effectively prevents ink contamination, ensures high-quality printing by reducing misdirected droplets and missing jets, and maintains its performance even after extensive maintenance cycles, improving the holding pressure and reducing ink weeping from nozzles.
Implementation Method 1
the coating comprises an oleophobic polymeric material wherein, when the surface coating is disposed on an ink jet printhead front face surface, jetted drops of ultra-violet gel ink or jetted drops of solid ink exhibit very little adhesion towards the surface
Data Source
AI summary
A coating for an ink jet printhead front face, wherein the coating comprises a low adhesion coating, wherein when the low adhesion coating is disposed on an ink jet printhead front face surface, jetted drops of ultra-violet gel ink or jetted drops of solid ink exhibit a low sliding angle with the printhead front face surface, wherein the low sliding angle is less than about 1° to less than about 30°. In embodiments, the low adhesion coating is an oleophobic coating that exhibits a contact angle of greater than about 35° with ultra-violet gel ink or solid ink.