Ink Composition for Piezo Printers Resolving Nozzle Blocking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Commercial ink jet printers face challenges with ink stability, nozzle blocking, and strike-through issues due to high print speeds and varied substrates, which are not adequately addressed by existing inks, leading to poor dot definition and increased risk of nozzle clogging.

Innovation Solution

The development of an ink composition comprising diethylene glycol mono alkyl ether, glycerol, pentan-1,5-diol, colorants, 2-pyrollidinone, surfactants, and polyalkylene glycol, with specific viscosity, surface tension, and pH ranges, designed to minimize nozzle blocking and strike-through while maintaining good drop definition on diverse substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If print speed is increased to meet commercial printing demands, then productivity is improved, but the risk of ink drying and crusting on nozzles increases

Engineering Contradiction:
Improveprint speedVSAvoidnozzle blocking risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the ink by incorporating specific additives (surfactants, solvents, and polymers) that change the ink's drying characteristics. This allows the ink to maintain appropriate drying speed at high print velocities while preventing premature crust formation on nozzles during non-printing periods

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The ink formulation is designed to be dynamic in its drying behavior - maintaining fluidity during active printing at high speeds to prevent nozzle blockage, while controlling the transition to a stable state on the substrate. The surfactant and polymer components create a time-dependent viscosity profile that adapts to the printing cycle

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If ink dries more quickly to prevent smudging on high-speed prints, then manufacturing precision is improved, but the risk of nozzle crusting increases

Engineering Contradiction:
Improvedot definitionVSAvoidnozzle blocking risk
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent adjusts multiple ink parameters simultaneously - surface tension, volatility, and viscosity - through the addition of surfactants and specific solvent blends. This creates an optimized drying curve that achieves rapid initial wetting for sharp dot definition while preventing excessive surface drying that would cause nozzle crusting

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The surfactant and polymer additives act as intermediaries that mediate between the conflicting requirements of rapid drying and nozzle protection. These components modify the ink's interaction with both the substrate and the nozzle surface, enabling precise dot placement without premature solidification in the nozzle

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of substance

If conventional inks are used on thin substrates to reduce cost, then loss of substance is reduced, but dot definition deteriorates due to feathering

Engineering Contradiction:
Improvesubstrate costVSAvoiddot definition
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent modifies the ink's rheological parameters - particularly viscosity and surface tension - to control ink flow and penetration behavior. The adjusted viscosity prevents excessive ink spread (feathering) on thin substrates, while the surface tension modification ensures adequate wetting for sharp edge acuity, all while using cost-effective substrate materials

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The ink formulation creates localized control over ink behavior - maintaining higher viscosity at the ink-substrate interface to prevent feathering, while allowing controlled penetration for adequate absorption. This local quality control enables precise dot definition on thin, cost-effective substrates

Inventive Principle:
Principle #3Local quality

4Reliability

If ink viscosity is reduced to improve flow and prevent nozzle blocking, then reliability is improved, but drop definition may deteriorate

Engineering Contradiction:
Improvenozzle flow stabilityVSAvoiddrop definition
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent optimizes the viscosity parameter within a specific range (3-10 cP) and modifies the ink's shear-thinning characteristics through polymer additives. This creates a non-Newtonian flow behavior where the ink maintains lower effective viscosity during nozzle flow to prevent blocking, but retains sufficient viscosity at rest for precise drop formation and definition

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 ink composition effectively reduces nozzle blocking and strike-through, ensuring stable printing with improved drop definition and edge acuity on a wide range of substrates, even thin and absorbent papers, while maintaining low viscosity and surface tension for efficient commercial print operations.

Implementation Method 1

Thin substrates such as those used in newspapers can suffer from poor dot definition due to 'feathering' of the ink across the paper

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

0 to 3 parts surfactant; The ink composition effectively reduces nozzle blocking and strike-through, ensuring stable printing with improved drop definition and edge acuity

Methodology Applied
Scientific EffectSurface tension reduction: Surface Tension

Implementation Method 3

Increasing print speed often means that the ink jet ink should desirably dry more quickly such that the final print does not smudge when stacked

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2539406A1inks
Publication Date: 2013.01.02 FUJIFILM IMAGING COLORANTS

AI summary

An ink composition comprising: a) 0.2 to 11 parts diethylene glycol mono alkyl ether; b) 20 to 45 parts glycerol; c) 0.5 to 8 parts pentan-1,5-diol; d) 0.5 to 9 parts colorant; e) 40 to 70 parts water; f) 0 to 8 parts 2-pyrollidinone; g) 0 to 3 parts surfactant; h) 0 to 5 parts in total of polyalkylene glycol and/or polyalkylene glycol ether having, in each case having a MWT of at least 5,000; and i) 0 to 5 parts biocide; wherein all parts are by weight. Also claimed are ink sets. The inks and ink sets are particularly useful for piezo ink jet printers.