Ink Set Moisture Control for Duplex Printing Speed

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Solution Overview

Problem

Current line type ink jet printers using aqueous ink face challenges in duplex printing due to moisture-related issues such as sheet deformation, paper jam, and ink transfer to sheet transporting mechanisms, leading to significantly slower speeds compared to simplex printing.

Innovation Solution

An ink set comprising black pigment ink, self-dispersing color pigment ink, and resin-dispersion color pigment ink with specific moisture content and additives like acetylene glycol-based surfactants, alkylene glycol monoalkyl ether, and trimethylglycine, which suppress ink transfer and deformation, allowing for faster duplex printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If aqueous ink is used for high-speed printing, then printing speed is improved, but sheet deformation and paper jam occur due to moisture

Engineering Contradiction:

Improveprinting speedVSAvoidsheet transporting reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent changes the moisture content parameter of the aqueous ink to a specific range (65-75 mass%) to resolve the contradiction. By controlling the moisture content within this range, the ink achieves optimal balance between infiltration speed and sheet deformation prevention, enabling high-speed printing without paper jam or excessive curling

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite ink formulations containing multiple components including surfactants (0.1-5 mass%), solvents, and pigments. This composite approach allows the ink to maintain low viscosity for fast infiltration while controlling moisture content to prevent sheet deformation, thus resolving the contradiction between speed and reliability

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If high-viscosity ink is used to prevent sheet deformation, then sheet stability is improved, but infiltration to sheet becomes slow

Engineering Contradiction:

Improvesheet stabilityVSAvoidinfiltration speed

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent changes the viscosity parameter by controlling moisture content (65-75 mass%) and adding surfactants (0.1-5 mass%). This creates an optimal viscosity range that enables both rapid infiltration and sheet stability, resolving the contradiction between infiltration speed and sheet stability

Inventive Principle:

Principle #35Parameter changes

3Productivity

If printing is performed on back surface immediately after front surface, then duplex printing speed is improved, but ink transfers to sheet transporting mechanism

Engineering Contradiction:

Improveduplex printing speedVSAvoidink transfer

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by ensuring the front surface ink is sufficiently infiltrated and dried before back surface printing. The controlled moisture content (65-75 mass%) and surfactant addition enable the ink to infiltrate rapidly during the transport time, preventing ink transfer to the transporting mechanism while maintaining high duplex printing speed

Inventive Principle:

Principle #10Preliminary action

4Speed

If moisture quantity of ink is increased, then infiltration speed is improved, but sheet deformation and curling increase

Engineering Contradiction:

Improveinfiltration speedVSAvoidsheet shape

Core Design Contradiction:

SpeedVSShape

Solution Approach 1:

The patent optimizes the moisture content parameter to a specific range (65-75 mass%) that balances infiltration speed and sheet shape maintenance. This parameter optimization ensures rapid ink infiltration while preventing excessive moisture from causing sheet deformation or curling

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 set enhances sheet transporting properties and significantly increases duplex printing speed by preventing ink transfer to the sheet transporting mechanism and minimizing sheet deformation, enabling speeds comparable to laser printers.

Implementation Method 1

each of the black pigment ink, the self-dispersing color pigment ink, and the resin-dispersion color pigment ink may contain three or more types of acetylene glycol-based surfactants selected from a group of acetylene glycol and an ethylene oxide adduct of acetylene glycol

Methodology Applied

Scientific EffectSurfactant: Surfactant

Implementation Method 2

the ink is infiltrated to a sheet rapidly, and thus an effect of suppressing the occurrence of transfer of the ink to the sheet transporting mechanism is obtained

Methodology Applied

Scientific EffectWetting: Wetting

Implementation Method 3

the ink is infiltrated to a sheet rapidly

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentUS10370550B2Ink set and duplex printing method

Publication Date: 2019.08.06 SEIKO EPSON CORP

AI summary

According to the invention, there is provided an ink set which contains at least one ink selected from a group of a black pigment ink, a self-dispersing color pigment ink, and a resin-dispersion color pigment ink. The moisture quantity of the black pigment ink is from 68 mass % to 75 mass %. The moisture quantity of the self-dispersing color pigment ink is from 62 mass % to 72 mass %. The moisture quantity of the resin-dispersion color pigment ink is from 68 mass % to 75 mass %.