HEMC Support Material for Water-Soluble 3D Printing

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Solution Overview

Problem

Current three-dimensional printing technologies face challenges with support materials that are difficult to remove without damaging the build material, often leaving toxic or corrosive residues and compromising mechanical integrity, and existing solutions add complexity or fail to provide adequate adhesion.

Innovation Solution

The use of hydroxyethyl methylcellulose with a specific degree of substitution and molar substitution, which can be easily removed with water at neutral pH, providing good adhesion to the build material and avoiding toxic residues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional support materials (HIPS, PLA, PVA) are used, then support function is provided, but toxic or corrosive residues are generated during removal

Engineering Contradiction:
Improvetoxic residuesVSAvoidsupport material removability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the support material by using a copolymer with specific ratios of lactide and glycolide units (5-45 mol% lactide, 55-95 mol% glycolide). This parameter optimization enables the support material to be removed with water at neutral pH without generating toxic residues, while maintaining adequate adhesion and support functionality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a support material designed for single-use disposal after serving its support function. The copolymer support material is intentionally made easy to remove through water dissolution, accepting that it will be discarded rather than reused. This aligns with the disposable nature of support materials that fulfill their purpose and are then removed.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Ease of operation

If PVA is used as support material, then water-soluble removal is achieved, but adhesion to build material is insufficient and printing is difficult

Engineering Contradiction:
Improveremoval easeVSAvoidprinting quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent uses a copolymer composite material combining lactide and glycolide units in specific proportions. This composite structure provides both water solubility for easy removal and adequate adhesion properties for successful printing. The combination of different polymer units creates a material that balances contradictory requirements of ease of removal and printing quality.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the compositional parameters of the support material by controlling the mol percentage of lactide (5-45%) and glycolide (55-95%) units. This parameter adjustment tunes the material properties to achieve both good adhesion during printing and sufficient water solubility for easy removal, resolving the contradiction between printing quality and removal ease.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If organic carriers are used for support material removal, then removal efficiency is improved, but oily residues are deposited on the part

Engineering Contradiction:
Improveremoval efficiencyVSAvoidoily residues
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the chemical mechanism of organic carrier-based removal with a water-based dissolution mechanism. Instead of using organic solvents that leave oily residues, the copolymer support material is designed to dissolve directly in water through hydrolysis and solvation of the ester groups, eliminating the need for organic carriers and the associated harmful residues.

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

Solution Approach 2:

The patent contains ester groups in the copolymer backbone that can undergo hydrolysis in water. This chemical property, which could be seen as a vulnerability, is actually exploited as a benefit - the water-soluble ester linkages enable easy removal of the support material without requiring harsh organic solvents, converting a potential weakness into a useful feature.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Speed

If elevated temperatures are used for support material removal, then removal speed is improved, but mechanical integrity of the build material is compromised

Engineering Contradiction:
Improveremoval speedVSAvoidmechanical integrity
Core Design Contradiction:
SpeedVSStrength

Solution Approach 1:

The patent changes the temperature parameter for support material removal from elevated temperatures to ambient or mild temperatures. The copolymer's water solubility and hydrolysis properties allow effective removal at lower temperatures, preventing thermal damage to the build material while maintaining adequate removal speed through the chemical properties of the copolymer structure.

Inventive Principle:
Principle #35Parameter changes

5Ease of operation

If release material coating is applied between build material and support material, then support material removal is facilitated, but process complexity increases and oily residues may be deposited

Engineering Contradiction:
Improveremoval easeVSAvoidprinting process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for separate release material coatings by incorporating release properties directly into the copolymer support material formulation. The support material itself is designed to have controlled adhesion characteristics that allow easy removal without requiring an additional release layer, simplifying the overall process while maintaining ease of removal.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The copolymer support material performs multiple functions simultaneously: it provides structural support during printing, adheres adequately to the build material, and enables easy water-based removal. This multi-functionality eliminates the need for separate release material coatings, reducing process complexity while maintaining ease of removal.

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

The hydroxyethyl methylcellulose support material allows for efficient and non-toxic removal from three-dimensionally printed articles, maintaining mechanical integrity and reducing surface tackiness, while offering good adhesion and thermoplastic characteristics for effective 3D printing.

Implementation Method 1

The support material may comprise a hydroxyethyl methylcellulose having a DS of 1.7 to 2.5 and an MS of at least 0.5... allows for efficient and non-toxic removal from three-dimensionally printed articles

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 2

providing good adhesion to the build material... offering good adhesion and thermoplastic characteristics for effective 3D printing

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

thermoplastic characteristics for effective 3D printing... builds the support material in a layer-by-layer fashion

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3307839B1Support materials for 3D printing
Publication Date: 2019.02.27 DOW GLOBAL TECHNOLOGIES LLC

AI summary

A three-dimensionally printed article is comprised of a hydroxyethyl methylcellulose (HEMC) having a DS of 1.7 to 2.5 and an MS of at least 0.5, wherein DS is the degree of substitution of methoxyl groups and MS is the molar substitution of hydroxyethoxyl groups. The HEMC may advantageously be used as a support material when making a three-dimensionally printed article using a build material such as a different thermoplastic polymer such as a poly(acrylonitrile-butadiene-styrene), polylactic acid, polyethylene and polyprophylene. When the HEMC is a support material it may be easily removed from the build material by contacting the three dimensionally printed article with water, which may be at ambient temperatures and a pH that is neutral or close to neutral.