Inkjet Printhead Aperture Plate Nanocoating for Nozzle Clogging Prevention
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Solution Overview
Problem
Existing coating technologies for inkjet printhead front faces struggle to form a uniform, micron-thick coating without partially or completely covering or clogging the nozzles, leading to issues like ink adhesion, contamination, and degraded print quality due to wetting, drooling, and flooding.
Innovation Solution
A method involving inkjet printing to deposit a layer of coating material on the aperture plate of an inkjet printhead, using low-adhesion polymers with easy-clean and self-clean properties, allowing precise positioning and application of coatings around nozzles and other regions without obstructing them, and using a combination of materials like isocyanates and fluoro-crosslinking agents to achieve low sliding angles and resistance to contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional coating technologies (sputtering, dipping, flowing, chemical vapor deposition) are used to form a uniform micron-thick coating on the printhead front face, then coating uniformity and thickness control are improved, but the nozzles are partially or completely covered or clogged
Solution Approach 1:
The coating application process is segmented into multiple sequential passes rather than a single thick application. Each pass deposits a thin layer of coating material, allowing the material to cure or set before the next pass. This segmentation prevents nozzle clogging while building up a uniform micron-thick coating over multiple cycles.
Solution Approach 2:
The printhead is prepared beforehand by positioning it on a platen and aligning the aperture plate with the inkjet coating head. The coating material is prepared in a jettable formulation state before application. These preliminary actions ensure that the coating can be applied precisely without misalignment that would cause nozzle coverage.
2Object-generated harmful factors
If the printhead front face is left uncoated, then nozzle accessibility is maintained, but ink adhesion, wetting, drooling, and flooding occur leading to contamination and degraded print quality
Solution Approach 1:
The surface energy parameters of the printhead front face are changed by applying a coating material with different wettability characteristics. The coating material is selected to have low surface energy that resists ink adhesion and prevents wetting, drooling, and flooding, while still allowing the nozzles to function properly.
Solution Approach 2:
A composite coating structure is applied to the printhead front face that combines materials with complementary properties. The coating may include multiple layers or a multi-component formulation that provides both the anti-adhesion properties needed to prevent ink contamination and the structural integrity needed to maintain nozzle accessibility.
3Reliability
If maintenance procedures (jetting/purging and wiping) are performed to clear inkjet blockages and clean the printhead front face, then nozzle blockages are removed, but the front face becomes wetted and contaminated by jetted/purged ink
Solution Approach 1:
The coating is applied in advance to the printhead front face to create a protective barrier that prevents ink from adhering during maintenance procedures. This preliminary anti-action ensures that when jetting or purging is performed, the ink does not stick to the front face, allowing gravity to cause the ink to slide into the waste reservoir without contamination.
4Object-affected harmful factors
If a coating is applied to the printhead front face to prevent ink adhesion, then ink contamination is reduced, but cleaning residue remains causing further contamination
Solution Approach 1:
The coating material is selected to have self-cleaning properties where ink residue does not adhere strongly enough to remain after normal cleaning operations. The coating surface is designed so that contaminants are easily removed without leaving residue, and the coating itself does not degrade or leave behind harmful substances that would cause further contamination.
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 method produces printheads with high-quality, high-throughput digital printing capabilities, reducing print defects by preventing ink adhesion and ensuring effective cleaning cycles without nozzle clogging, maintaining low sliding angles even after multiple cleaning cycles.
Implementation Method 1
depositing a layer of coating material to a surface of the aperture plate by inkjet printing to form a coating on at least a portion of the surface of the aperture plate
Implementation Method 2
using low-adhesion coatings that resist contamination and flooding
Data Source
AI summary
A method for producing an inkjet printhead that includes aligning and stacking together an aperture plate and a plurality of jetstack plates; bonding together the aperture plate and plurality of jetstack plates; after the bonding step, depositing a layer of coating material to a surface of the aperture plate by inkjet printing to form a coating on at least a portion of the surface of an outlet surface of the aperture plate; and curing the layer of coating material to form a cured coating. The method may also include forming a second cured coating.