Reactive Inkjet Printing of Polycarbonate Precursors

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Solution Overview

Problem

Current additive manufacturing methods, such as extrusion printing and selective laser sintering, cannot produce transparent polycarbonate structures, and they face issues with high viscosity of polycarbonate solutions in inkjet printing and uneven curing due to the requirement of ultraviolet light, which often results in adhesion problems between layers.

Innovation Solution

The method involves 3D inkjet printing of reactive polycarbonate precursor solutions with low viscosity that can be polymerized using heat, allowing for even and reliable curing, and enabling crosslinking between layers to form transparent or substantially transparent polycarbonate structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If extrusion printing or selective laser sintering is used to prepare polycarbonate materials, then polycarbonate structures can be fabricated, but transparent polycarbonate structures cannot be produced

Engineering Contradiction:
ImprovetransparencyVSAvoidfabrication capability
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the material state from solid polycarbonate to reactive precursor solutions that can be jetted, then transforms them back to solid polycarbonate through controlled polymerization. This parameter change enables transparency while maintaining fabrication capability through inkjet printing deposition and subsequent curing.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If polycarbonate materials are used in inkjet printing form, then transparency can be achieved, but the viscosity is too high for inkjet printing

Engineering Contradiction:
ImprovetransparencyVSAvoidviscosity
Core Design Contradiction:
Manufacturing precisionVSForce

Solution Approach 1:

The patent performs preliminary action by converting polycarbonate into reactive precursor compounds dissolved in solvents before printing. These precursors are prepared in advance with appropriate solvent selection to achieve low viscosity, enabling successful inkjet printing while maintaining the ability to form transparent structures after curing.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If ultraviolet light curing is used in inkjet printing, then curing can be achieved, but line-of-sight requirement causes uneven curing

Engineering Contradiction:
ImprovecuringVSAvoidcuring uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces the optical curing mechanism (UV light requiring line-of-sight) with a thermal/chemical polymerization mechanism using reactive precursors that cure through heat or chemical reaction. This substitution eliminates the line-of-sight constraint and enables uniform curing throughout the printed structure regardless of geometry.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If conventional inkjet printing methods are used, then printing can be performed, but adhesion between layers is poor

Engineering Contradiction:
Improveprinting capabilityVSAvoidlayer adhesion
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent uses composite material strategy by employing reactive precursor solutions containing multiple functional components that enable both printable流动性 and strong interlayer bonding. The reactive nature of the precursors creates chemical bonds between layers during curing, significantly improving adhesion while maintaining printing capability.

Inventive Principle:
Principle #40Composite materials

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 fabrication of transparent polycarbonate structures with improved adhesion between layers and uniform curing, overcoming the limitations of existing methods by using heat-polymerizable reactive precursors in a controlled environment.

Implementation Method 1

reactive polycarbonate precursor compounds that can be polymerized by the application of heat

Methodology Applied
Scientific EffectPolymerization:

Implementation Method 2

curing, which can be applied evenly and reliably

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

react and crosslink between layers

Methodology Applied
Scientific EffectCrosslinking: Chemical Bonding

Data Source

PatentEP3291970B1System and method for reactive inkjet printing of polycarbonate
Publication Date: 2019.12.18 SABIC GLOBAL TECHNOLOGIES BV
  • EP3291970B1 patent drawingFigure 1
  • EP3291970B1 patent drawingFigure 2
  • EP3291970B1 patent drawingFigure 3

AI summary

A system comprises one or more print heads (18,20,22) configured to selectively print droplets (34,36,38) of one or more polycarbonate precursor solutions comprising one or more polycarbonate precursor compounds onto one or more target locations on a substrate to form one or more reactive mixture droplets at each target location, and an environmental system configured to expose the reactive mixture droplets to reaction conditions that polymerize the one or more polycarbonate precursor compounds to form a polycarbonate. A method comprises printing droplets of one or more polycarbonate precursor solutions comprising one or more polycarbonate precursor compounds onto one or more target locations on a substrate to form a reactive mixture droplet at each target location, and exposing the reactive mixture droplets to reaction conditions to polymerize the one or more polycarbonate precursor compounds to form a polycarbonate.