Windshield Interlayer Film Groove Angle for Vacuum Deaeration Yield

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Solution Overview

Problem

The vacuum deaeration method for producing automotive windshields with interlayer films featuring recesses in the shape of engraved lines results in low yield due to displacement of glass and interlayer film during handling, which affects deaeration properties.

Innovation Solution

The interlayer film has a large number of recesses and projections with a groove shape and continuous bottom, inclined at 35° or more relative to the machine direction, enhancing deaeration properties and preventing displacement between glass and interlayer film during the production process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If recesses in the shape of engraved lines are regularly formed in the interlayer film, then deaeration properties are improved, but displacement of glass and interlayer film occurs during handling, reducing production yield

Engineering Contradiction:
Improvedeaeration propertiesVSAvoidproduction yield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The recesses are configured with asymmetric dimensions in the machine direction versus the transverse direction. Specifically, the length of recesses in the machine direction is made longer than their width in the transverse direction, creating an elongated groove shape. This asymmetric configuration allows the recesses to effectively trap and remove air during vacuum deaeration while their extended length in the machine direction provides enhanced mechanical interlocking with the glass, preventing displacement during handling and transport.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If recesses with groove shape and continuous bottom are used, then deaeration efficiency is enhanced, but glass and interlayer film displacement occurs during transport, lowering yield

Engineering Contradiction:
Improvedeaeration efficiencyVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The recesses are designed with a specific dimensional ratio between their length in the machine direction and their width in the transverse direction. By making the recesses elongated in the machine direction (length greater than width), the design utilizes the machine direction as an additional functional dimension. This dimensional configuration serves dual purposes: the groove shape with continuous bottom provides efficient air evacuation pathways, while the extended length in the machine direction creates mechanical anchoring that prevents displacement during transport and handling.

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

This configuration improves deaeration properties and increases the yield of automotive windshields by reducing displacement issues during the vacuum deaeration method, ensuring better bonding and handling efficiency.

Implementation Method 1

The laminate is vacuum suctioned, so that the laminate is preliminarily pressure-bonded while the air remaining between the glass plate and the interlayer film is removed.

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

A laminated glass in which two glass plates and an interlayer film for an automotive windshield containing a thermoplastic resin, such as plasticized polyvinyl butyral, are bonded to one another

Methodology Applied
Scientific EffectLamination: Lamination

Data Source

PatentEP3632872B1Vehicle-windshield-glass intermediate film, rolled body, and vehicle windshield glass
Publication Date: 2024.07.03 SEKISUI CHEMICAL CO LTD
  • EP3632872B1 patent drawingFigure 1~3
  • EP3632872B1 patent drawingFigure 4(a)~4(b)

AI summary

The present invention aims to provide an interlayer film for an automotive windshield which, while having recesses in the shape of engraved lines, enables the production of automotive windshields with high yield by a vacuum deaeration method; a roll of the interlayer film for an automotive windshield; and an automotive windshield including the interlayer film for an automotive windshield. The present invention relates to an interlayer film for an automotive windshield. The interlayer film includes, on at least one surface thereof, a large number of recesses and a large number of projections. The recesses have a groove shape with a continuous bottom. The recesses are adjacently arranged regularly side by side in parallel with one another. The recesses in a groove shape with a continuous bottom are inclined 35° or more relative to the machine direction of the film in production of the interlayer film for an automotive windshield.