3D Printing Coalescing Agent for Uniform Fusing

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Solution Overview

Problem

Current 3D printing technologies face challenges in achieving uniform cosmetic and improved mechanical properties of 3D objects due to limitations in coalescing agents, particularly with regards to dynamic surface tension and radiation absorbance efficiency.

Innovation Solution

A 3D printing system and method utilizing a coalescing agent with a co-solvent, surfactant, and polymerically dispersed carbon black pigment, which has a hydrophilic lipophilic balance (HLB) value less than 10, and a balance of water, applied via an inkjet applicator and exposed to electromagnetic radiation to selectively fuse polymer build materials, enhancing radiation absorbance and mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional coalescing agents are used in 3D printing, then the process can be completed, but the cosmetic uniformity and mechanical properties of the 3D objects are insufficient

Engineering Contradiction:
Improvecosmetic uniformityVSAvoidmechanical properties
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The coalescing agent is formulated as a composite material containing multiple components: carbon black particles (for radiation absorption), surfactant (for surface tension control and uniform distribution), and co-solvent (for proper solubility and evaporation characteristics). This composite structure allows simultaneous achievement of cosmetic uniformity through surfactant-mediated distribution and mechanical strength through controlled radiation absorption and fusion.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes specific parameters of the coalescing agent including carbon black particle size distribution (affecting radiation absorption efficiency), surfactant concentration (controlling surface tension and spreadability), and co-solvent composition (influencing evaporation rate and final uniformity). By precisely controlling these parameters, both cosmetic appearance and mechanical properties are improved.

Inventive Principle:
Principle #35Parameter changes

2Strength

If higher amounts of coalescing agent are used to improve mechanical properties, then strength increases, but cosmetic uniformity deteriorates due to poor distribution

Engineering Contradiction:
Improvetensile strengthVSAvoidcosmetic uniformity
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The surfactant acts as an intermediary substance that mediates between the coalescing agent components and the polymer build material. It reduces surface tension, enables uniform distribution of carbon black particles throughout the polymer matrix, and ensures consistent radiation absorption without aggregation. This intermediary action allows use of adequate coalescing agent amounts for strength while maintaining cosmetic uniformity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If carbon black pigment is added to enhance radiation absorbance, then fusion efficiency improves, but the formulation complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveradiation absorbance efficiencyVSAvoidformulation complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The invention extracts and isolates the radiation-absorbing function to carbon black particles, which are added as a discrete component to the coalescing agent formulation. This separation allows optimization of radiation absorption independently from other functions (surfactancy, solubility), simplifying the overall formulation approach. Each component can be selected and optimized independently for its specific function.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution results in 3D objects with improved tensile strength, Young's modulus, and strain properties, and better cosmetic uniformity, even when using reduced amounts of the coalescing agent, compared to traditional methods.

Implementation Method 1

the coalescing agent absorbs the electromagnetic radiation and heats up the portion of the build material in contact with the coalescing agent

Methodology Applied
Scientific EffectElectromagnetic radiation absorption: Absorption (EM radiation)

Implementation Method 2

heats up the portion of the build material in contact with the coalescing agent to fuse the portion of the build material

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

a surfactant having a hydrophilic lipophilic balance (HLB) value that is less than 10

Methodology Applied
Scientific EffectSurfactant action: Surfactant

Implementation Method 4

a co-solvent having a boiling point of less than 300°C

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 5

heats up the portion of the build material in contact with the coalescing agent to fuse the portion of the build material

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3200977B1Three-dimensional (3D) printing system
Publication Date: 2021.06.02 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3200977B1 patent drawingFigure 1
  • EP3200977B1 patent drawingFigure 2A~2D
  • EP3200977B1 patent drawingFigure 2E~3

AI summary

A three-dimensional (3D) printing system includes a fabrication bed, a build material to be introduced into the fabrication bed, an inkjet applicator, a coalescing agent to be selectively introduced by the inkjet applicator onto the build material in the fabrication bed, and a radiation source to expose the coalescing agent and the build material in the fabrication bed to electromagnetic radiation. The coalescing agent includes a co-solvent having a boiling point of less than 300C, a surfactant having a hydrophilic lipophilic balance (HLB) value that is less than 10, a carbon black pigment, a polymeric dispersant, and a balance of water.