Sacrificial Coating for Intermediate Transfer Member Ink Wetting

Solution Overview

Problem

Inkjet printers face challenges in achieving optimal ink spreading and coalescing on intermediate transfer members due to the conflicting requirements of high surface energy for wet ink quality and low surface energy for image transfer, with existing materials and ink designs failing to balance these needs effectively.

Innovation Solution

A sacrificial coating composition is developed by emulsifying oil with a surfactant to form an oil-in-water emulsion, combining hydrophilic polymers, hygroscopic materials, and water, which is applied to the intermediate transfer member to enhance ink wetting and spreading while ensuring efficient image transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a high surface energy blanket material is used, then ink spreading and wetting is improved, but ink release and transfer to media substrate deteriorates

Engineering Contradiction:

Improvewet image qualityVSAvoidimage transfer

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention divides the blanket surface into two distinct layers: a base layer with low surface energy material (silicone, fluorosilicone, fluoropolymer, or hybrid) for good ink release, and a sacrificial top layer with high surface energy materials (polymer, latex, hygroscopic material, oil-in-water emulsion) for excellent ink wetting and spreading. This segmentation allows each layer to perform its specialized function without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sacrificial coating is applied locally as a thin top layer (0.01-10 micrometers) on the blanket surface, creating a localized high surface energy region only where ink contact occurs. The underlying low surface energy base layer remains exposed in areas not covered by the sacrificial coating, maintaining good release properties while providing enhanced wetting where needed.

Inventive Principle:

Principle #3Local quality

2Reliability

If a low surface energy blanket material is used, then ink release and transfer to media substrate is improved, but ink spreading and wetting deteriorates

Engineering Contradiction:

Improveimage transferVSAvoidwet image quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention divides the blanket surface into two distinct layers: a base layer with low surface energy material (silicone, fluorosilicone, fluoropolymer, or hybrid) for good ink release, and a sacrificial top layer with high surface energy materials (polymer, latex, hygroscopic material, oil-in-water emulsion) for excellent ink wetting and spreading. This segmentation allows each layer to perform its specialized function without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sacrificial coating is applied locally as a thin top layer (0.01-10 micrometers) on the blanket surface, creating a localized high surface energy region only where ink contact occurs. The underlying low surface energy base layer remains exposed in areas not covered by the sacrificial coating, maintaining good release properties while providing enhanced wetting where needed.

Inventive Principle:

Principle #3Local quality

3Reliability

If ink surface tension is increased, then print head performance is improved, but ink spreading on blanket deteriorates

Engineering Contradiction:

Improveprint head performanceVSAvoidink spreading

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention changes the surface energy parameter of the blanket surface by applying a sacrificial coating with high surface energy materials. This allows the use of inks with higher surface tension (optimized for print head performance) while still achieving good spreading on the blanket, as the sacrificial coating provides the necessary high surface energy interface between the ink and blanket.

Inventive Principle:

Principle #35Parameter changes

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 sacrificial coating composition improves ink spreading and coalescing on the intermediate transfer member, leading to better wet image quality and enhanced image transfer efficiency, reducing residual ink on the blanket and allowing for lower transfer temperatures.

Implementation Method 1

emulsifying an oil with surfactant to form an oil-in-water emulsion

Methodology Applied

Scientific EffectEmulsion: Emulsion

Implementation Method 2

emulsifying an oil with surfactant to form an oil-in-water emulsion

Methodology Applied

Scientific EffectSurfactant: Surfactant

Implementation Method 3

Spreading of aqueous ink is facilitated by materials having a high energy surface

Methodology Applied

Scientific EffectWetting: Wetting

Implementation Method 4

the ink is partially dried on the blanket prior to transfixing the image

Methodology Applied

Scientific EffectCohesion: Cohesion

Data Source

PatentUS9611404B2Method of making sacrificial coating for an intermediate transfer member of indirect printing apparatus

Publication Date: 2017.04.04 GENESEE VALLEY INNOVATIONS LLC

AI summary

A method of making a sacrificial coating composition is disclosed. The method comprises emulsifying an oil with surfactant to form an oil-in-water emulsion; and combining ingredients comprising (i) at least one polymer, (ii) at least one hygroscopic material, (iii) the oil-in water emulsion and (iv) water to produce the sacrificial coating composition. The at least one polymer is selected from the group consisting of a hydrophilic polymer, a latex comprising polymer particles dispersed in a continuous liquid phase, or mixtures thereof.