Thin Glass Cut Edge Structure for Higher Bending Strength
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Solution Overview
Problem
Existing methods for cutting thin glass ribbons are unreliable due to unstable laser processes and result in glass edges with low bending strength, leading to reduced service life and stability.
Innovation Solution
A method and apparatus for scoring thin glass using a rigid scoring tool that generates a deep crack with a directional elastic strain zone parallel to the glass surface and perpendicular to the separation line, followed by applying a bending or tensile load to separate the glass along the crack, enhancing edge strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser-induced stress-crack cleaving is used to cut thin glass ribbons, then cutting speed and automation are improved, but the process becomes unstable and cracks drift when cutting long ribbons
Solution Approach 1:
The patent replaces the optical laser system with a mechanical scoring tool that creates a deep crack in the glass. This mechanical approach provides stable and predictable crack propagation along the intended separation line, eliminating the drift issue observed with laser methods while maintaining high cutting speed and automation capability.
Solution Approach 2:
The patent changes the fundamental parameter of crack initiation from optical energy deposition (laser) to mechanical stress concentration (scoring tool). By controlling the mechanical parameters of the scoring tool (geometry, pressure, feed rate), the process achieves stable crack formation that does not drift, thereby improving reliability while preserving productivity.
2Ease of manufacture
If conventional scoring methods are used to cut glass, then manufacturing simplicity is maintained, but edge strength is significantly lower than face strength
Solution Approach 1:
The patent applies local quality by creating a deep, controlled crack with specific geometric characteristics (arcuate zone of elastic strain) at the edge region. This localized crack geometry, with one leg near the surface and the other leg inside the glass, creates compressive stresses that strengthen the edge while maintaining the simplicity of the mechanical scoring process.
Solution Approach 2:
The patent introduces curvature into the crack path by creating an arcuate zone of elastic strain. This curved crack geometry, rather than a straight line, distributes stresses more favorably and creates compressive regions that enhance edge strength, while the process remains as simple as conventional mechanical scoring.
3Productivity
If glass edges are left as-cut from conventional methods, then no additional processing is needed, but fracture predominantly emanates from edges reducing service life
Solution Approach 1:
The patent performs preliminary action by creating a deep, pre-controlled crack during the scoring process itself. This pre-formed crack with its specific arcuate geometry prepares the glass edge in advance to resist fracture initiation, eliminating the need for additional edge strengthening processes and directly improving service life by preventing fracture propagation from the edge.
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
The method produces glass edges with high resistance to bending loads, allowing for reliable cutting and improved service life, suitable for applications in consumer electronics and other fields requiring high edge strength.
Implementation Method 1
the scoring tool, by being pressed onto the glass surface and due to the advancement force while introducing the deep crack generates a zone of elastic strain in the glass with a directional component of the elastic strain parallel to the glass surface and perpendicular to the separation line
Implementation Method 2
Thus, the method ensures that a tensile stress is built up in the glass directly below the scoring tool, causing crack formation in the form of a deep crack
Data Source
AI summary
A sheet-like glass element has a thickness less than or equal to 0.5 mm and an edge with an edge face intersecting opposite glass faces along two edge lines. The edge face has strip-like sections with each one adjoining a respective one of the edge lines. The strip-like sections interface along a boundary line that extends between the edge lines. The strip-like sections have a first section with a width ranging from 2 μm to 8 μm and have a first waviness that is lower than a second waviness of a second strip-like section. The second waviness decreases towards the edge line.