Optical Feedback for Cationic Inkjet Precision

Solution Overview

Problem

Current 3D printing techniques using inkjet printers face challenges with UV-curable cationic inks due to slow curing times, which hinder precision and lead to defects or fouling of the printer, as mechanical surface control methods are not feasible and optical scanning is inadequate due to insufficient optical signal strength.

Innovation Solution

Incorporating an optical feedback system that controls the emission of UV-curable cationic inks with an optical enhancement component, allowing for non-contact surface control and precise deposition of cationic polymerizable components, such as epoxy or oxetane functional groups, and photoacid generators, while partially curing the material to enable accurate layering and improved material properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If UV-curable cationic inks are used in inkjet printing, then material properties such as flexibility and isotropy are improved, but curing time increases leading to precision loss and printer fouling

Engineering Contradiction:

Improvematerial propertiesVSAvoidcuring time

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The patent replaces mechanical planarization systems (rollers,刮 blades) with an optical feedback system using scanners to detect surface geometry. This allows the slow-curing cationic ink to remain uncured during scanning, eliminating the conflict between mechanical contact and uncured material while maintaining precision through optical measurement and closed-loop control of deposition parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the uncured ink's own optical properties (scanned by optical sensors) to provide feedback for controlling subsequent deposition. The material itself serves as the sensing medium, eliminating the need for separate fast-curing layers or mechanical intervention, and allowing the slow-curing material to be directly used in the feedback loop.

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If mechanical planarization is used to control surface geometry, then manufacturing precision is improved, but it is not feasible with slow-curing cationic inks due to defects and fouling

Engineering Contradiction:

Improvesurface geometry controlVSAvoidprocess feasibility

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces mechanical planarization systems (rollers,刮 blades) with an optical feedback system using scanners to detect surface geometry. This allows the slow-curing cationic ink to remain uncured during scanning, eliminating the conflict between mechanical contact and uncured material while maintaining precision through optical measurement and closed-loop control of deposition parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If conventional acrylates are used for rapid curing, then productivity is improved, but material properties such as flexibility and isotropy are insufficient

Engineering Contradiction:

Improvecuring speedVSAvoidmaterial properties

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The patent replaces mechanical planarization systems (rollers,刮 blades) with an optical feedback system using scanners to detect surface geometry. This allows the slow-curing cationic ink to remain uncured during scanning, eliminating the conflict between mechanical contact and uncured material while maintaining precision through optical measurement and closed-loop control of deposition parameters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements closed-loop feedback by scanning the uncured material's surface geometry and using this information to control subsequent deposition parameters. This feedback mechanism compensates for the slow curing time by continuously monitoring and adjusting the process, ensuring precision without requiring rapid curing.

Inventive Principle:

Principle #23Feedback

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 approach enables the production of precision objects with enhanced material properties, including isotropic and flexible structures, by tolerating slow curing times and using predictive techniques to accommodate material changes during the fabrication process, thus overcoming the limitations of conventional jetted acrylates.

Implementation Method 1

UV curable cationic compound

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS11926103B2Precision system for additive fabrication

Publication Date: 2024.03.12 INKBIT LLC

AI summary

An approach to precision additive fabrication uses jetting of cationic compositions in conjunction with a non-contact (e.g., optical) feedback approach. By not requiring contact to control the surface geometry of the object being manufactured, the approach is tolerant of the relative slow curing of the cationic composition, while maintaining the benefit of control of the deposition processes according to feedback during the fabrication processes. This approach provides a way to manufacture precision objects and benefit from material properties of the fabricated objects, for example, with isotropic properties, which may be at least partially a result of the slow curing, and flexible structures, which may not be attainable using conventional jetted acrylates.