Variable Ink Application for 3D Printing Edge Bonding

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Solution Overview

Problem

In three-dimensional powder lamination fabrication methods, the edge regions of fabrication layers experience heat loss to non-fabrication regions when radiant energy is applied, leading to inadequate bonding of powder particles, resulting in decreased accuracy and strength of the fabrication layer.

Innovation Solution

A method and apparatus where a droplet containing a radiation absorber is applied multiple times to specific divided regions of the fabrication layer, and radiant energy is applied with variable intensity to these regions, ensuring sufficient heat retention for bonding at the edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If radiant energy is applied to the fabrication region, then the powder particles are solidified and bonded, but heat escapes to the non-fabrication region causing insufficient bonding at edges

Engineering Contradiction:
Improvebonding strength of fabrication layerVSAvoidtemperature at edge of fabrication region
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent applies different ink amounts to different regions: standard droplet amounts in the central fabrication region and increased droplet amounts specifically at edge regions adjacent to non-fabrication regions. This local differentiation ensures that edge regions receive additional radiation absorber to compensate for heat loss, maintaining bonding temperature and strength at boundaries while using standard amounts in the center where heat retention is sufficient.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies the radiation absorber concentration parameter by varying the ink application amount based on spatial location. Edge regions are assigned a higher radiation absorber concentration (through increased droplet amounts) compared to central regions. This parameter change enables edge regions to absorb more radiant energy and compensate for heat escape to non-fabrication regions, resolving the temperature deficit at boundaries.

Inventive Principle:
Principle #35Parameter changes

2Strength

If the amount of ink is increased at the edge of fabrication region, then radiation absorption is improved and bonding strength increases, but the complexity of controlling variable ink amounts increases

Engineering Contradiction:
Improvebonding strength at edge regionVSAvoidcomplexity of ink application control
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent segments the fabrication region into distinct zones: a central region with standard ink application and edge regions with increased ink application. This segmentation is implemented by dividing the fabrication area and applying different droplet amounts to different segments. The segmentation approach simplifies control by creating clear spatial boundaries for different ink amounts rather than requiring continuous variable control across the entire region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent determines and marks edge regions in advance before ink application, identifying which areas require increased droplet amounts. This preliminary identification of edge regions allows the system to pre-plan the variable ink application pattern, simplifying the control process by eliminating the need for real-time complex calculations during the fabrication process.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If standard droplet amount is applied uniformly across the fabrication region, then the application process is simple, but edge regions experience heat loss and insufficient bonding

Engineering Contradiction:
Improvesimplicity of ink application processVSAvoidaccuracy of fabrication layer at edge
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements local quality differentiation by applying standard droplet amounts to the central fabrication region and increased droplet amounts specifically to edge regions. This local adaptation ensures that edge regions, which experience heat loss to non-fabrication regions, receive additional radiation absorber to maintain bonding temperature and dimensional accuracy, while the central region maintains standard application simplicity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies the ink application parameter (droplet amount) based on spatial location to maintain manufacturing precision. Edge regions are assigned increased droplet amounts to compensate for heat escape and ensure accurate bonding, while central regions use standard amounts. This parameter change is implemented through a controlled variation strategy that maintains overall process simplicity while achieving the precision needed at critical edge locations.

Inventive Principle:
Principle #35Parameter changes

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 enhances the accuracy and strength of the fabrication layer at the edge regions by maintaining the necessary bonding temperature despite heat loss to non-fabrication regions, improving both the precision and structural integrity of the fabricated object.

Implementation Method 1

applying an ink containing a radiation absorber to a fabrication region on a surface of a powder layer and applying radiant energy thereto to solidify the powder

Methodology Applied
Scientific EffectRadiation absorption: Absorption (EM radiation)

Implementation Method 2

At an edge of the fabrication region adjacent to a non-fabrication region, when radiant energy is applied thereto, heat escapes to the non-fabrication region

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP3587075B1Method for fabricating object and apparatus for fabricating object
Publication Date: 2022.01.05 RICOH CO LTD
  • EP3587075B1 patent drawingFigure 1
  • EP3587075B1 patent drawingFigure 2
  • EP3587075B1 patent drawingFigure 3

AI summary

A method for fabricating an object includes forming, first applying, second applying, and repeating. The forming forms a powder layer (31). The first applying applies a droplet (10) containing a radiation absorber to the powder layer (31). The second applying applies radiant energy to the powder layer (31). The repeating repeats the forming, the first applying, and the second applying. The first applying includes applying the droplet (10) to a surface of the powder layer (31) to form a fabrication region; dividing the fabrication region into a plurality of divided regions; and applying the droplet (10) a plurality of times to a partial specific divided region among the plurality of divided regions. The second applying includes applying the radiant energy with a variable radiation intensity to a range including at least the specific divided region.