Electrostatic Coloring Unit for Continuous 3D Printing

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Solution Overview

Problem

Current 3D printing methods for colored objects face challenges in achieving high-quality color variation and efficiency, particularly in FDM processes, where the need for multiple filaments and print heads limits color range and quality, and interrupts the printing process for color changes.

Innovation Solution

The method involves acquiring geometry and color information from a 3D digital model, using a transporting unit to deposit materials on a forming surface, and employing an electrostatically charged coloring unit with opposite polarity to mix and fuse color with the material, allowing continuous color application without filament changes, enabling a wide range of colors and improved color transitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple filaments and print heads are used to achieve color variation in FDM printing, then color range and quality are improved, but device complexity and printing process interruption increase

Engineering Contradiction:
Improvecolor rangeVSAvoidnumber of filaments and print heads
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The coloring function is segmented from the printing function. A separate coloring unit with electrostatic charge is introduced that can apply color to the material during transport, independent of the print head. This allows a single print head to maintain structural simplicity while the coloring unit provides versatile color application through electrostatic field control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An electrostatic field is introduced as an intermediary mechanism between the coloring unit and the material. The electrostatically charged coloring unit transfers color to the material without direct contact, enabling color variation while maintaining a simple printing apparatus structure and avoiding the need for multiple print heads.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If multiple filaments are used for color changes, then color quality is improved, but productivity decreases due to filament changes interrupting the printing process

Engineering Contradiction:
Improvecolor transitionsVSAvoidprinting efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The material is pre-charged with electrostatic charge during transport before reaching the print head. The coloring unit applies color in advance during the transport phase, so that when the material reaches the print head, the color is already applied. This preliminary coloring action eliminates the need for filament changes and maintains continuous printing productivity while achieving sharp color transitions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The coloring process is made continuous by applying color during the material transport phase through the electrostatically charged coloring unit. This continuous coloring action occurs without interrupting the printing process, maintaining productivity while ensuring sharp color transitions are achieved through controlled electrostatic field application.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of manufacture

If color is applied after material deposition, then printing process is simple, but color mixing and fusion quality deteriorates

Engineering Contradiction:
Improveprinting process simplicityVSAvoidcolor fusion quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The material is pre-charged with electrostatic charge during transport before deposition. This preliminary electrostatic charging enables the coloring unit to effectively transfer color to the material during transport, ensuring optimal color fusion quality before the material reaches the print head, while maintaining the simplicity of the printing process.

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 allows for high-quality, continuous 3D printing of colored objects without the need for multiple filaments or print heads, ensuring sharp color transitions and increased efficiency by mixing color with the material before printing, thus enhancing the manufacturing process.

Implementation Method 1

both the material (16) and a coloring unit (14) are electrostatically charged with opposite polarities respectively

Methodology Applied
Scientific EffectElectrostatic charge: Electrostatics

Implementation Method 2

transmission of the color to the material (16) from the coloring unit (14) due to the opposite polarities

Methodology Applied
Scientific EffectElectrostatic attraction: Ion Repulsion/Attraction

Implementation Method 3

heating the material (16) to fuse the color with the material

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

The material is heated in a liquefier to a molten state and then is extruded

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3461617B1Method and apparatus for printing colored three dimensional objects
Publication Date: 2020.02.19 BAYERISCHE MOTOREN WERKE AG
  • EP3461617B1 patent drawingFigure 1
  • EP3461617B1 patent drawingFigure 2

AI summary

A method for printing at least one colored three dimensional (3D) object by means of a printing apparatus (10), the method comprising: acquiring information regarding geometry and color of the object to be printed from a 3D digital model; transporting a material (16) to be used for the printing of the at least one colored 3D object on a forming surface; printing the 3D object from the material (16) in form of material layers on the forming surface according to the acquired information; electrostatically charging the material (16) and a coloring unit (14) of the printing apparatus (10) with opposite polarities; application of color to the coloring unit (14) according to the acquired information; transmission of the color to the material (16) from the coloring unit (14) due to the opposite polarities; and mixing the material (16) with the color.