Release Layer Coating via Reverse Gravure for Print Quality
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Solution Overview
Problem
Existing electrostatic printing systems face difficulties in controlling the surface roughness of release layers on intermediate transfer members, leading to issues such as 'fog' in printed images, 'butterflies' patterns, and increased failure rates due to substrate primer accumulation.
Innovation Solution
A method of coating a web with a release formulation using a rotatable applicator roller and impression roller, applying a release formulation comprising silicone oil and a cross-linker, and curing it to form a release layer with an average surface roughness of less than 3 µm, using techniques like reverse gravure or off-set reverse gravure coating methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional coating methods are used to apply release layer, then the release layer can be formed, but the surface roughness cannot be controlled below 3 µm
Solution Approach 1:
The patent changes the coating parameters by using reverse gravure or off-set reverse gravure coating methods with specific roller configurations and coating conditions to achieve the required surface roughness of less than 3 µm, which cannot be obtained by conventional coating methods
Solution Approach 2:
The patent introduces an intermediary coating process where a release formulation is applied through a gravure coating system with specific anilox rollers and doctor blades, acting as a mediator between the release layer material and the final surface to achieve the desired roughness control
2Ease of manufacture
If release layer with high surface roughness is used, then the coating process is simpler, but image defects like 'fog' and 'butterflies' occur
Solution Approach 1:
The patent changes the surface roughness parameter of the release layer to less than 3 µm through specialized coating methods, which eliminates image defects such as fog and butterflies that occur with rougher surfaces
3Ease of manufacture
If conventional release layer is used, then the initial function is provided, but substrate primer accumulation increases causing faster blanket failure
Solution Approach 1:
The patent changes the surface morphology parameter of the release layer through controlled coating processes, creating a smoother surface that reduces substrate primer accumulation and extends blanket operational life
Solution Approach 2:
The patent inverts the conventional coating approach by using reverse gravure or off-set reverse gravure methods where the coating is applied in reverse sequence, preventing primer accumulation from the outset rather than dealing with it later
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 intermediate transfer members with smooth release layers, reducing image defects like 'fog' and 'butterflies', and minimizing substrate primer accumulation, thereby enhancing print quality and extending the lifespan of the rubber blankets.
Implementation Method 1
applying a release formulation comprising silicone oil and a cross-linker, and curing it to form a release layer
Implementation Method 2
applying the release formulation coating to the web under a shearing force by rotating the applicator roller such that, at a location at which the web and the applicator roller engage, the surface of the applicator roller moves in the opposite direction to the direction the web is fed
Data Source
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AI summary
Herein is disclosed a method of coating a web with a release formulation. The method comprising: providing a coating station comprising a rotatable applicator roller to apply a release formulation coating to a web; applying a release formulation coating to a surface of the applicator roller, the release formulation comprising at least one silicone oil; feeding the web through the coating station such that the web engages with the applicator roller; and applying the release formulation coating to the web under a shearing force by rotating the applicator roller such that, at a location at which the web and the applicator roller engage, the surface of the applicator roller moves in the opposite direction to the direction the web is fed through the coating station.