3D Fabrication Liquid Discharge Pattern for Boundary Accuracy

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The accuracy of three-dimensional fabricated products using the powder lamination method is reduced due to bleeding and spreading of solidifying and non-solidifying liquids during discharge, which affects the precision of the boundary between bonded and unbonded regions.

Innovation Solution

A three-dimensional fabricating apparatus that discharges solidifying and non-solidifying liquids adjacent to each other in the same scan, using a specific discharge pattern to prevent bleeding and spreading, thereby improving the accuracy of the fabricated product.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If discharge is performed in accordance with a mask pattern with multiple pass interlaces to enhance resolution, then the resolution is improved, but the solidifying liquid and non-solidifying liquid are discharged to positions away from each other, causing bleeding and spreading that reduces accuracy

Engineering Contradiction:
Improvedischarge resolutionVSAvoidboundary accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The discharge process is segmented into two distinct patterns: a first discharge pattern for solidifying liquid that prioritizes boundary accuracy, and a second discharge pattern for non-solidifying liquid that fills remaining regions. This segmentation allows each liquid type to be optimized independently, preventing the bleeding and spreading that occurs when both are discharged using the same high-resolution multi-pass pattern.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solidifying liquid is discharged first using a mask pattern designed to prevent bleeding, establishing accurate boundaries before the non-solidifying liquid is discharged. This preliminary action ensures that the boundary-defining liquid is placed precisely, and subsequent discharge of the non-solidifying liquid does not compromise this accuracy.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If a single discharge pattern is used for both solidifying and non-solidifying liquids, then the process is simple, but the liquids are discharged to distant positions causing bleeding and spreading

Engineering Contradiction:
Improvedischarge pattern complexityVSAvoidboundary accuracy
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The single discharge pattern is divided into two specialized patterns: a first discharge pattern optimized for solidifying liquid that ensures adjacent discharge of solidifying and non-solidifying liquids, and a second discharge pattern for non-solidifying liquid. This segmentation prevents the bleeding and spreading that occurs with unified discharge while maintaining manageable process complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different discharge patterns are applied to different liquid types based on their specific requirements. The solidifying liquid receives a discharge pattern optimized for boundary accuracy and adjacent discharge, while the non-solidifying liquid receives a pattern optimized for its filling function. This local optimization ensures each liquid achieves its specific purpose without compromising overall precision.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If multiple pass interlaces are used to discharge liquid, then resolution is improved, but solidifying and non-solidifying liquids are discharged to positions away from each other

Engineering Contradiction:
Improvedischarge resolutionVSAvoidliquid placement accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The multi-pass interlaced discharge is segmented into separate discharge operations for solidifying and non-solidifying liquids. The solidifying liquid is discharged first with a pattern that ensures adjacent positioning, and the non-solidifying liquid is discharged afterward with a complementary pattern, eliminating the positioning errors that occur when both are discharged using the same multi-pass pattern.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solidifying liquid is discharged preliminarily using a pattern designed to ensure adjacent discharge positions, establishing accurate liquid placement before the non-solidifying liquid is discharged. This preliminary discharge with optimized positioning prevents the placement accuracy losses that occur with subsequent multi-pass interlaced discharge of both liquids together.

Inventive Principle:
Principle #10Preliminary action

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 productivity of the fabricated products by ensuring precise boundary definition between solidifying and non-solidifying portions, facilitating better removal of excess powder and improving the overall quality of the three-dimensional printed items.

Implementation Method 1

a liquid discharge unit that discharges a fabrication liquid to a powder layer

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

prevent bleeding and spreading of solidifying and non-solidifying liquids

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 3

a fabricator that forms a layer-wise fabricated product by combining the fabrication liquid with the powder layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3539774B1Three-dimensional fabricating apparatus and three-dimensional fabricating method
Publication Date: 2023.09.06 RICOH CO LTD
  • EP3539774B1 patent drawingFigure 1
  • EP3539774B1 patent drawingFigure 2~3
  • EP3539774B1 patent drawingFigure 4

AI summary

According to an embodiment, a three-dimensional fabricating apparatus includes a supply unit (21), a flattening unit (12), a discharge unit (50), and a controller (500). The supply unit (21) is configured to supply powder (20). The flattening unit (12) is configured to flatten a surface of the supplied powder and form a powder layer. The discharge unit (50) is configured to discharge a first fabrication liquid solidifying the powder and a second fabrication liquid not solidifying the powder onto a surface of the powder layer. The controller (500) is configured to cause the discharge unit to discharge the first fabrication liquid and the second fabrication liquid in accordance with a discharge pattern in which the second fabrication liquid is discharged to a region adjacent to at least some of a plurality of regions in which the first fabrication liquid is discharged.