Core-Shell Tube FDM Printing for Weight Reduction

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Solution Overview

Problem

Current 3D printing methods using FDM are inefficient in reducing the weight of printed items while maintaining structural integrity and smooth surfaces, as they rely on solid materials with high material usage.

Innovation Solution

The method involves using a core-shell-shell structure with a hollow tube core and two shells, where the hollow tube is printed alongside the 3D printable material, allowing for layer-wise deposition to create a lightweight 3D item with a core-shell-shell layer, using a standard FDM printer with a core-shell nozzle and a cutting element to manage the hollow tube's presence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If solid materials are used in FDM printing, then structural integrity is maintained, but weight and material usage increase

Engineering Contradiction:
Improveweight of printed itemVSAvoidstructural integrity
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The printed item is segmented into multiple hollow tubes arranged in parallel, replacing solid material with a structured assembly of hollow elements. This segmentation maintains structural integrity through the collective strength of multiple tubes while significantly reducing overall material usage and weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses hollow tube structures with empty interiors, creating a porous-like configuration that reduces material density by up to 30% compared to solid materials. The hollow tubes provide structural support while minimizing material consumption, achieving both weight reduction and maintained strength.

Inventive Principle:
Principle #31Porous materials

2Quantity of substance

If hollow tube structures are used to reduce material density, then weight is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvematerial densityVSAvoidprinting process complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The hollow tubes are nested within the 3D printable material matrix, with the tubes positioned inside the extruded material. This nested configuration allows the complex hollow tube structure to be integrated within a simpler outer material shell, reducing overall manufacturing complexity while maintaining the material reduction benefits.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention creates a composite structure combining hollow tubes with 3D printable material, where the two materials work together to provide both structural support and material efficiency. This composite approach simplifies the manufacturing process by using standard FDM technology with modified material feeding, rather than requiring entirely new manufacturing methods.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If hollow tubes are printed layer-wise, then material usage is reduced, but surface smoothness may be compromised

Engineering Contradiction:
Improvematerial usageVSAvoidsurface smoothness
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The 3D printable material is applied locally around the hollow tubes, with varying thicknesses in different regions. The material density and distribution are optimized locally to ensure surface smoothness in visible areas while maintaining material efficiency in less critical regions. This local quality adjustment preserves surface appearance while achieving overall material reduction.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The hollow tubes extend in the vertical dimension through multiple layers, providing structural support that reduces the need for excessive horizontal material layering. By utilizing the vertical dimension effectively with continuous tubes, the invention reduces overall material usage while the outer 3D printable material layers maintain surface smoothness through proper extrusion and fusion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 reduces the material density by up to 30% compared to solid materials, maintaining structural integrity and surface smoothness, while allowing for the creation of lightweight 3D printed items with customizable properties.

Implementation Method 1

a 3D printing stage comprising layer-wise depositing core-shell-shell material via a printer nozzle

Methodology Applied
Scientific EffectExtrusion: Extrusion

Implementation Method 2

the filament is melted and extruded before being laid down

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

FDM works on an 'additive' principle by laying down material in layers; a plastic filament or metal wire is unwound from a coil and supplies material to produce a part

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP4192670B1Continuous hollow tube printing using fdm
Publication Date: 2024.10.09 SIGNIFY HOLDING BV
  • EP4192670B1 patent drawingFigure 1A~1B
  • EP4192670B1 patent drawingFigure 1C
  • EP4192670B1 patent drawingFigure 1D~1E

AI summary

The invention provides a method comprising producing a 3D item (1) by means of fused deposition modelling using a fused deposition modeling 3D printer (500), the method comprising a 3D printing stage comprising layer-wise depositing core-shell-shell material (1201) via a printer nozzle (502) on a receiver item (550), wherein the core-shell- shell material (1201) comprises a hollow tube (1210) comprising a hollow core (1220) and a first shell (1230) enclosing the hollow core (1220), and 3D printable material (201) at least partly enclosing the first shell (1230), to provide the 3D item (1) comprising a core-shell- shell layer (1322), wherein the core-shell-shell layer (1322) comprises the hollow tube (1210) comprising the hollow core (1220) and the first shell (1230) enclosing the hollow core (1220), and 3D printed material (202) at least partly enclosing the first shell (1230).