Toy Building Brick Additive Manufacturing Surface Precision

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Solution Overview

Problem

Existing additive manufacturing techniques, such as filament extrusion-based methods, suffer from poor dimensional precision and visible surface irregularities, making it difficult to produce toy building elements with complex geometries and acceptable surface quality.

Innovation Solution

The use of alternative additive manufacturing techniques like photopolymerization, thermoplastic, liquid-based, toner-based, and powder-based methods that involve the repeated solidification or deposition of polymeric materials, allowing for improved dimensional precision and surface smoothness without the need for post-treatment to hide layer visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If filament extrusion-based additive manufacturing technique is used, then the manufacturing process is simple and accessible, but the dimensional precision and surface quality are poor with visible layer lines

Engineering Contradiction:
Improvedimensional precisionVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the fundamental parameters of the additive manufacturing process by transitioning from filament extrusion to alternative methods such as material jetting, binder jetting, or powder bed fusion. These parameter changes enable achieving Ra and Rq values below 100 µm, resolving the contradiction between manufacturing precision and process complexity by selecting processes inherently capable of high precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical filament extrusion system with alternative deposition or fusion mechanisms. For example, material jetting uses droplet ejection instead of filament extrusion, and powder bed fusion uses selective laser or electron beam fusion instead of mechanical layer deposition. This substitution achieves superior surface quality and dimensional precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If filament extrusion-based additive manufacturing technique is used, then the manufacturing process is straightforward, but the surface roughness is high and separate layers are visible

Engineering Contradiction:
Improvesurface roughnessVSAvoidease of manufacture
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the material deposition parameters by using techniques that deposit material in a manner that eliminates visible layer lines. Material jetting deposits fine droplets that fuse into smooth surfaces, while binder jetting uses controlled binder distribution to create uniform surfaces. These parameter changes achieve Ra and Rq below 100 µm while maintaining manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the filament extrusion mechanical system with systems that inherently produce smoother surfaces. Material jetting replaces extrusion with droplet deposition, and powder bed fusion replaces layer-by-layer extrusion with selective powder fusion. These substitutions eliminate the stair-stepping effect and visible layer lines characteristic of filament extrusion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If traditional manufacturing methods are used, then the production volume is high, but the geometric complexity is limited

Engineering Contradiction:
Improveproduction volumeVSAvoidgeometric complexity
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing complex geometries into manageable layers or regions that can be additively manufactured with high precision. This allows traditional manufacturing to handle high-volume production of simple parts while additive manufacturing handles complex geometries, achieving both high productivity and geometric complexity through a hybrid approach.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent leverages the third dimension inherent in additive manufacturing to create complex geometries that are impossible with traditional methods. By building in the Z-dimension layer by layer, the process achieves high geometric complexity while maintaining scalability for production volume through automated layer-by-layer construction.

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

These methods enable the production of toy building elements with significantly improved surface roughness and appearance, with arithmetical mean height (Ra) and root mean square height (Rq) values below 100 µm, ensuring that material layers are not visible to the naked eye and providing enhanced interconnectivity and assembly characteristics.

Implementation Method 1

photopolymerization additive manufacturing

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

repeated solidification of a thin liquid layer or droplet on a substrate or on a previously solidified liquid layer or droplet

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

thermoplastic additive manufacturing

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

repeated printing with a thermoplastic polymeric material on a substrate or on a previously printed plastics material

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3717089B1An additively manufactured toy building brick
Publication Date: 2024.05.01 LEGO AS
  • EP3717089B1 patent drawingFigure 1

AI summary

The present invention relates to a method for the manufacture of a toy building element made of a polymeric material using an additive manufacturing technique as the manufacturing process. The present invention also relates to a toy building element produced by said additive manufacturing process.