3D-Printed Lighting Component Using Thermal Stress Shaping

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current 3D-printing methods face challenges in achieving the right balance between adhesion to the build plate and thermal stress management, leading to issues like delamination, warping, and deformation in printed objects, particularly in producing complex shapes for lighting devices.

Innovation Solution

A method involving a flexible substrate and a polymer or monomer material where the printing structure causes the substrate to change shape due to internal stress from shrinking, allowing for controlled deformation into a predetermined shape, utilizing thermal or polymerization stress to form complex geometries without constraint-induced deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the object is strongly adhered to the build plate during printing, then the object remains stable and does not shift or delaminate, but the adhesion becomes difficult to remove without damaging the object or requiring post-processing steps

Engineering Contradiction:
Improveadhesion stabilityVSAvoidremoval difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The build plate is pre-heated to a temperature above the glass transition temperature of the thermoplastic material before printing begins. This preliminary heating action ensures that the material remains in a flowable state during initial adhesion, allowing easy removal later while maintaining stability during printing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The temperature of the build plate is dynamically controlled - maintained above the glass transition temperature during printing to ensure easy removal, while the cooling of printed layers creates thermal stress that provides sufficient adhesion stability during the printing process.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the printed layers are constrained during cooling down, then the object remains stable, but thermal stress leads to undesired deformation or crack formation

Engineering Contradiction:
Improvestructural stabilityVSAvoidshape accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The build plate temperature is dynamically adjusted during the printing process - heated above the glass transition temperature to allow free thermal contraction and prevent stress buildup, then cooled in a controlled manner to achieve the desired shape without constraint-induced deformation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The process utilizes the glass transition phase transition of the thermoplastic material. By maintaining the build plate above the glass transition temperature, the material remains in a rubbery state that can accommodate thermal stress without deforming or cracking, then transitions to a glassy state for final shape stabilization.

Inventive Principle:
Principle #36Phase transitions

3Reliability

If the build plate temperature is kept low, then thermal stress is reduced, but the object may not adhere properly to the build plate

Engineering Contradiction:
Improveadhesion qualityVSAvoidthermal stress
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The build plate temperature is raised above the glass transition temperature of the thermoplastic material, changing the material's physical state to improve adhesion. This parameter change allows the material to bond more effectively to the build plate while the controlled cooling process manages thermal stress.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The process creates a composite structure where the thermoplastic material bonds to the heated build plate surface. The temperature differential between the hot build plate and cooler ambient air creates a controlled thermal gradient that manages stress while maintaining adhesion.

Inventive Principle:
Principle #40Composite materials

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 enables the production of complex shapes with improved manufacturing efficiency, reduced post-processing needs, and enhanced thermal, mechanical, and optical properties, while minimizing delamination and warping, by leveraging internal stress for shaping the substrate.

Implementation Method 1

an internal stress in the polymer material exerts a bending force on a surface area of the flexible substrate, wherein the bending force forces a displacement of the flexible substrate into the second shape

Methodology Applied
Scientific EffectThermal stress: Thermal Expansion

Implementation Method 2

a polymerization stress of the monomer material exerts a bending force on a surface area of the flexible substrate. The bending force forces a displacement of the flexible substrate into the second shape

Methodology Applied
Scientific EffectPolymerization stress: Photopolymerisation

Data Source

PatentEP3609679B1Method of 3d-printing producing a component for use in a lighting device
Publication Date: 2021.10.27 SIGNIFY HOLDING BV
  • EP3609679B1 patent drawingFigure 1A~1B
  • EP3609679B1 patent drawingFigure 2
  • EP3609679B1 patent drawingFigure 3~4

AI summary

It is an object of the invention to provide an improved method of 3D-printing producing a component for use in a lighting device. Thereto, the invention provides a method of 3D-printing producing a component for use in a lighting device, the component comprising a flexible substrate having a stiffness and a polymer material or a monomer material, the method comprising printing the polymer material or the monomer material onto the flexible substrate in a printing structure; wherein the printing structure causes the flexible substrate to change into a second shape when the polymer material or the monomer material shrinks after printing; wherein an internal stress in the polymer material or the monomer material exerts a bending force on a surface area of the flexible substrate, wherein the bending force forces a displacement of the flexible substrate into the second shape.