Sheet Glass Separation Along Curved Lines Without Splinters

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for separating portions from sheet glass elements along non-rectilinear separation lines are inefficient, often resulting in damaged parts and the generation of splinters, making it difficult to achieve clean and precise separation, especially for curved or closed-loop shapes.

Innovation Solution

The method involves using ultrashort pulse lasers to create filamentary damages along the separation line, followed by heating the main part and cooling the portion to induce thermal stresses, allowing for precise separation without additional auxiliary cuts, thereby minimizing damage and ensuring both parts remain intact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional laser separation methods are used on non-rectilinear separation lines, then separation can be achieved, but the glass portions are damaged and splinters are generated

Engineering Contradiction:

Improveseparation precisionVSAvoidglass damage and splinters

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The separation process is divided into two distinct stages: first creating filamentary damages along the separation line using ultrashort pulse lasers, then applying thermal stress to complete the separation. This segmentation allows each stage to be optimized independently, achieving clean separation without glass damage or splinters.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention changes the physical state and parameters of the glass by heating the main part and cooling the portion to create thermal stress. This parameter change enables clean separation along the filamentary damages without generating splinters or damaging the glass portions.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If additional auxiliary cuts are made to achieve complete separation, then portions can be separated, but processing complexity increases

Engineering Contradiction:

Improveseparation efficiencyVSAvoidprocessing complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The ultrashort pulse laser creates filamentary damages along the entire separation line in advance, preparing the glass for subsequent thermal stress separation. This preliminary action eliminates the need for additional auxiliary cuts or complex multi-step mechanical separation processes.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If high energy is applied to separate glass portions, then separation can be achieved, but energy costs increase

Engineering Contradiction:

Improveseparation speedVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The ultrashort pulse laser applies high energy only along the narrow separation line to create filamentary damages, rather than applying energy across the entire glass surface. This partial action achieves effective separation while minimizing overall energy consumption.

Inventive Principle:

Principle #16Partial or excessive 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 enables efficient, splinter-free separation of glass portions along complex shapes with high edge quality, reducing the risk of cracking and allowing for the reuse of both parts, while also simplifying the processing complexity and reducing energy costs.

Implementation Method 1

the laser pulses generate a plasma within the volume of the glass element, which causes the filamentary damages

Methodology Applied

Scientific EffectPlasma generation: Plasma

Implementation Method 2

producing the damages by laser pulses of an ultrashort pulse laser

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

the glass element is heated in the region of the main part so as to cause expansion thereof

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 4

or is cooled in the region of the portion so as to cause contraction thereof

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Implementation Method 5

so that the portion detaches from the main part at the adjacently aligned filamentary damages along the separation line

Methodology Applied

Scientific EffectThermal stress: Thermomechanical Effect

Data Source

PatentUS11572301B2Method and device for laser-assisted separation of a portion from a sheet glass element

Publication Date: 2023.02.07 SCHOTT AG

AI summary

A method for separating a portion from a sheet glass element having a thickness of at least 2 millimeters along an intended separation line that divides the sheet glass element into the portion and a remaining main part is provided. The method includes producing filamentary damages comprising sub-micrometer hollow channels in a volume of the glass sheet element adjacently aligned along the separation line; and heating and/or cooling the glass sheet element to cause expansion and/or contraction so that the portion detaches from the main part along the separation line. The portion and the remaining main part each remain intact as a whole. The step of producing the filamentary damages includes generating a plasma within the volume with laser pulses of an ultrashort pulse laser; and displacing points of incidence of the laser pulses over a surface of the glass sheet element along the separation line.