Wedge-Shaped Multilayer Interlayer for Laminated Glass

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Solution Overview

Problem

Current manufacturing processes for wedge-shaped multilayer interlayers often result in inconsistent thickness of the internal functional layer, leading to inconsistent functional performance and increased defects such as rippling and gaps, which affect the optical and structural properties of laminated glass.

Innovation Solution

A wedge-shaped multilayer interlayer design featuring an integrated multilayer sheet with a consistent thickness, combined with a wedge-shaped film, where the integrated multilayer sheet forms the predominant portion of the thickness at both edges, ensuring consistent thickness and reduced manufacturing defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If wedge-shaped multilayer interlayer is produced via coextrusion of all layers, then the interlayer can be manufactured with varying thickness, but the internal functional layer thickness becomes inconsistent leading to defective products

Engineering Contradiction:
Improvemanufacturing process capabilityVSAvoidinternal layer thickness consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent divides the interlayer into two separate components: an integrated multilayer sheet with consistent thickness and a wedge-shaped film. This segmentation allows each component to be manufactured independently with optimal thickness control, then combined to achieve the desired wedge shape while maintaining internal layer consistency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary integrated multilayer sheet that serves as the base layer with consistent internal layer thickness. This intermediary component mediates between the manufacturing process requirements and the final wedge shape requirements, allowing the wedge shape to be achieved through the overlaying wedge-shaped film rather than through direct coextrusion of the entire structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If the internal layer thickness varies across the wedge shape, then the wedge shape can be formed, but the functional performance becomes inconsistent across the laminate

Engineering Contradiction:
Improvewedge shape formationVSAvoidfunctional performance consistency
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The patent segments the thickness variation function into a separate wedge-shaped film component rather than embedding it in the integrated multilayer sheet. This allows the internal layers to maintain consistent thickness for reliable functional performance, while the wedge shape is achieved through the geometry of the overlaying film.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by having the wedge-shaped film provide the thickness variation only where needed for the wedge shape, while the integrated multilayer sheet provides consistent thickness throughout. This allows different regions to have different thicknesses only where required by the wedge geometry, while maintaining consistent internal layer quality for functional performance.

Inventive Principle:
Principle #3Local quality

3Productivity

If conventional coextrusion process is used for wedge-shaped multilayer interlayer, then production can proceed, but manufacturing defects such as rippling and gaps increase

Engineering Contradiction:
Improveproduction capabilityVSAvoiddefect rate
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent segments the manufacturing process into two independent steps: producing the integrated multilayer sheet with consistent thickness, then overlaying it with a wedge-shaped film. This segmentation eliminates the complex simultaneous coextrusion of multiple layers with varying thickness, thereby reducing manufacturing defects such as rippling and gaps.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by first manufacturing the integrated multilayer sheet with consistent thickness before adding the wedge-shaped film. This preliminary preparation of the base layer with optimal thickness consistency prevents defects that would otherwise occur during the more complex simultaneous coextrusion process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3532290B1Wedge-shaped multilayer interlayer and glass laminate
Publication Date: 2022.01.05 KURARAY EURO GMBH
  • EP3532290B1 patent drawingFigure 1
  • EP3532290B1 patent drawingFigure 2~4
  • EP3532290B1 patent drawingFigure 5~6

AI summary

Provided is a wedge-shaped multilayer interlayer and a glass laminate containing such interlayer, wherein the interlayer is based on the combination of (a) an integrated multilayer interlayer sheet having an overall substantially consistent thickness and a substantially consistent thickness of an interior layer, and (b) a separate wedge-shaped film.