Inkjet Printhead Thread Coating to Reduce Water Consumption

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Solution Overview

Problem

Conventional thread coloring methods, such as dip-coating, consume large quantities of water and lack versatility, whereas digital inkjet printing technology offers a more efficient and versatile method for coloring threads.

Innovation Solution

Employing a pagewide printhead with rows of nozzles to eject ink onto threads longitudinally, utilizing multiple coating chambers for full color gamut coverage, and incorporating airflow, air pressure, or acoustic levitation to manage ink droplets for uniform coating, with optional thread rotation and vibration for improved uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional dip-coating methods are used for thread coloring, then color application is achieved, but water consumption increases significantly

Engineering Contradiction:

Improvewater consumptionVSAvoidcoloring method versatility

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent replaces the mechanical dip-coating process with a digital inkjet printing system that uses piezoelectric or thermal printheads to deposit colorant directly onto threads. This substitution eliminates the need for water-based rinsing and drying processes inherent in dip-coating, dramatically reducing water consumption while enabling precise digital color control and on-demand customization.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the physical state and delivery method of colorant from liquid dip-coating baths to digitally controlled inkjet droplets. By transforming the colorant application from a bulk liquid process to a precision droplet deposition system, the patent achieves both reduced water usage and enhanced versatility through digital color management and on-the-fly color mixing capabilities.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If conventional dip-coating methods are used for thread coloring, then color application is achieved, but processing time increases

Engineering Contradiction:

Improvethread coloring speedVSAvoidwater waste

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent replaces the multi-step mechanical dip-coating process (dipping, rinsing, drying) with a single-pass digital inkjet printing process. The inkjet system deposits colorant directly onto moving threads without requiring subsequent water rinsing or drying stages, thereby accelerating production speed and eliminating water waste associated with the traditional process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention implements continuous thread feeding through the inkjet printing zone, maintaining uninterrupted colorant deposition. Threads move continuously through the printing chamber while colorant is applied in real-time, eliminating the batch processing interruptions and idle time inherent in conventional dip-coating methods, thus improving overall productivity and reducing water consumption.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If pagewide printheads are used in unconventional manner for thread coating, then coating efficiency improves, but device complexity increases

Engineering Contradiction:

Improvecoating efficiencyVSAvoidprinthead arrangement complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent inverts the conventional printing approach by feeding threads lengthwise along the rows of nozzles rather than across them. This unconventional orientation allows the full width of the pagewide printhead to be utilized for coating multiple threads simultaneously in a single pass, dramatically improving coating efficiency while the modular printhead design keeps the system manageable.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention employs pagewide printheads designed for conventional media printing and adapts them for thread coating applications. By utilizing existing commercial inkjet technology in a novel configuration, the patent achieves high-speed multi-thread coating capability without requiring entirely new device development, thus improving productivity while limiting the increase in device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This method reduces water consumption and enhances the speed, versatility, and efficiency of thread coloring, enabling on-demand color application with reduced waste, while maintaining high ink coverage and uniformity.

Implementation Method 1

digital inkjet printing technology

Methodology Applied

Scientific EffectDigital inkjet printing:

Implementation Method 2

airflow in the coating chamber

Methodology Applied

Scientific EffectAirflow: Convection

Implementation Method 3

acoustic levitation

Methodology Applied

Scientific EffectAcoustic levitation: Acoustic Levitation

Implementation Method 4

the thread is vibrated as it is fed longitudinally along the length of the printhead

Methodology Applied

Scientific EffectVibration: Vibration

Data Source

PatentUS11511308B2Thread coating using inkjet printhead

Publication Date: 2022.11.29 MEMJET TECH LTD

AI summary

A method of coating threads using a printhead having rows of nozzles extending along a length of the printhead. The method includes the steps of: feeding the thread along a length of the printhead; and ejecting ink from the rows of nozzles towards the thread. Thread-coating modules and thread-coating systems make use of the method described.