3D Printing Support Material Segmentation for Boundary Precision

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Solution Overview

Problem

Current 3D printing methods face challenges in producing three-dimensional structures with exact contours and smooth surfaces due to the limitations of support materials, which often result in blurred boundaries and require mechanical post-treatment for residue removal.

Innovation Solution

A method involving the use of a free-radically curable object material and a cationically polymerizable support material, where the support material hardens by a different mechanism, allowing for easy removal with an aqueous medium, and optionally employing a secondary support material for enhanced support and cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the same photocrosslinkable material is used for both object and support material, then the manufacturing process is simplified, but the boundaries between object and support material become blurred and mechanical post-treatment is required

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidboundary precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent divides the support material into two distinct functional components: a water-soluble polymer matrix (e.g., polyvinyl alcohol, gelatin, starch) that provides structural support and can be easily removed, and a photocrosslinkable compound (e.g., acrylate, vinyl ether) that enables localized bonding. This segmentation allows the support material to fulfill both mechanical support and precise boundary definition functions simultaneously, resolving the contradiction between manufacturing simplicity and boundary precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a composite support material by combining water-soluble polymers with photocrosslinkable compounds. This composite structure enables the support material to have both the ease of removal characteristic of water-soluble materials and the precise boundary definition capability of crosslinked structures. The composite nature allows simplified manufacturing while maintaining high manufacturing precision at boundaries.

Inventive Principle:
Principle #40Composite materials

2Reliability

If mechanical post-treatment is applied to remove support material residues, then complete removal is achieved, but the production time increases and surface quality may be compromised

Engineering Contradiction:
Improvesupport material removal completenessVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces mechanical post-treatment methods with a chemical dissolution process. The water-soluble polymer matrix in the support material allows for easy removal by aqueous processing, eliminating the need for time-consuming mechanical operations. This substitution maintains complete removal reliability while significantly reducing production time and avoiding surface quality degradation associated with mechanical methods.

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

3Ease of operation

If a water-soluble polymer matrix is used in the support material, then easy removal is achieved, but the structural strength may be reduced

Engineering Contradiction:
Improvesupport material removal easeVSAvoidsupport material strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies local quality by creating regions of different crosslinking density within the support material. The water-soluble polymer matrix provides the base structure for easy removal, while localized photocrosslinking creates stronger regions where needed for structural support. This local differentiation allows the support material to maintain adequate strength during printing while remaining easily removable afterward, resolving the contradiction between ease of operation and structural strength.

Inventive Principle:
Principle #3Local quality

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 three-dimensional structures with exact contours and smooth surfaces, reducing the need for mechanical processing to remove support material residues and providing a cost-effective method for achieving precise geometric features.

Implementation Method 1

the object material comprising a free radically curable compound and a photoinitiator; radiation curing the object material

Methodology Applied
Scientific EffectFree radical photopolymerization: Photopolymerisation

Implementation Method 2

the support material comprising a cationically polymerizable compound and a photoacid generator; radiation curing the object material and support material

Methodology Applied
Scientific EffectCationic polymerization: Photopolymerisation

Implementation Method 3

removing the hardened support material by treatment with an aqueous medium

Methodology Applied
Scientific EffectDissolution: Solvation

Data Source

PatentEP3265877B1Method for producing a tridimensional structure by 3D printing
Publication Date: 2019.03.27 BASF SE
  • EP3265877B1 patent drawingFigure 1
  • EP3265877B1 patent drawing

AI summary

A method for producing a tridimensional structure by 3D printing comprises: (a) ejecting an object material through a first print head, the object material comprising a radically curable compound and a photoinitiator; (b) ejecting a supporting material through a second print head, the supporting material comprising a cationically polymerizable compound and a photoacid generator; (c) radiation curing the object material and the supporting material; steps (a) to (c) are repeated several times in order to form the tridimensional structure layer by layer, and the object material and the supporting material comprise at least one common boundary surface; and (d) removing the cured supporting material by treatment with an aqueous medium. The supporting material is suitable for supporting overhanging components and structures located above hollow spaces. The use of a supporting material cured by a different mechanism than the object material prevents undesirable interactions between the object material and the supporting material during curing.