Stripping Device Coupled to Light Source for 3D Printing

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Solution Overview

Problem

Conventional rapid prototyping methods for three-dimensional object production, such as stereolithography, suffer from inhomogeneous light intensity distribution due to the use of UV projectors, leading to uneven polymerization and prolonged construction times, and require complex intensity control to achieve homogenization.

Innovation Solution

A device and method that simultaneously guides a stripping device in front of a light source to form a projection surface while polymerizing light-curing plastic, using a surface light modulator to homogenize light intensity distribution, and a coupling mechanism to move the stripping device and light source together, allowing for simultaneous smoothing and exposure in a single process step.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a UV projector is used to illuminate the light-curing plastic, then the exposure process can be performed, but the light intensity distribution becomes inhomogeneous with higher intensity in the center and lower intensity at the edges

Engineering Contradiction:
Improvelight intensity distributionVSAvoidpolymerization uniformity
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by differentiating the treatment of different regions in the exposure field. The center region receives full light intensity while the edge regions receive reduced intensity through a graduated filter, compensating for the natural light falloff and achieving uniform polymerization across the entire projection surface.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the light intensity parameter spatially by introducing a graduated filter that attenuates light differently across the exposure field. This parameter modification transforms the inhomogeneous light distribution into a homogeneous one, ensuring consistent polymerization properties throughout the cured plastic layer.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the surface is removed with a squeegee before exposure, then the projection surface is prepared, but the process requires multiple sequential steps increasing construction time

Engineering Contradiction:
Improvesurface preparationVSAvoidconstruction time
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent merges the surface preparation function and the exposure function into a single integrated device. The stripping device is mechanically coupled to the light source carrier, allowing both the projection surface formation and the light exposure to occur simultaneously in one operational step, thereby eliminating the sequential waiting period between steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent achieves continuity of useful action by making the stripping device and light source move together continuously across the projection surface. This simultaneous operation eliminates idle time between surface preparation and exposure, maintaining continuous productive action throughout the layer formation process.

Inventive Principle:
Principle #20Continuity of useful action

3Device complexity

If a static exposure process is used, then the equipment design is simplified, but the construction time is significantly prolonged

Engineering Contradiction:
Improveequipment designVSAvoidconstruction time
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent introduces dynamic elements by making both the stripping device and the light source movable rather than static. They are coupled together and traverse the projection surface simultaneously, transforming the process from a static multi-step operation to a dynamic single-pass operation that maintains simplicity while dramatically reducing construction time.

Inventive Principle:
Principle #15Dynamics

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 significantly reduces construction time and ensures uniform polymerization of light-curing plastic, achieving homogeneous light intensity without complex intensity control, thus making the process more economical and efficient.

Implementation Method 1

Light-curing plastic is polymerized by means of a light source (1), in particular by means of electromagnetic radiation, preferably UV light

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3157735B1A more efficient method for producing three-dimensional objects by means of a rapid prototyping process
Publication Date: 2025.08.06 HERAEUS KULZER GMBH
  • EP3157735B1 patent drawingFigure 1~2
  • EP3157735B1 patent drawingFigure 3a~3b
  • EP3157735B1 patent drawingFigure 4~5

AI summary

The invention relates to a device and a method for producing three-dimensional objects (10), in particular at least parts of prosthetic dental supplies. A scraping device (20) scrapes plastic (6) projecting over the height of a container (8) into a collecting container (16) and forms a projection surface. According to the invention, a scraping device (20) and a light source (1) are coupled and are guided simultaneously with a defined spacing over the molten light-curing plastic (6). The scraping device (20) is guided directly in front of the light source (1) at a defined spacing thereto and forms a projection surface for the illumination field (5) of the light source (1).