Laminated glass with areas of different mechanical properties
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Solution Overview
Problem
Current laminated glass solutions for vehicle windshields and roofs require separate installation and framing due to differing mechanical properties, which is inefficient for aerodynamic and optical integration as a single piece of glazing.
Innovation Solution
An interlayer film with distinct areas having different mechanical properties, achieved by combining layers of polyvinyl acetal resin and plasticizers, allowing for adjustable storage modulus and adhesion to cover both windscreen and roof areas, enabling a single piece of laminated safety glass for automobiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate laminated glass frames are used for windshields and roofs, then each area can have optimized mechanical properties, but aerodynamic and optical integration is compromised
Solution Approach 1:
The patent merges the windshield and roof glazing into a single laminated glass unit by using an interlayer film with spatially varying mechanical properties. The interlayer film combines a first region with higher storage modulus for the windshield area and a second region with lower storage modulus for the roof area, eliminating the need for separate frames and achieving both mechanical optimization and aerodynamic integration.
Solution Approach 2:
The interlayer film is designed with local quality variations where different regions have different mechanical properties. The first region has a storage modulus G' of 50-500 MPa for windshield protection while the second region has a storage modulus G' of 10-200 MPa for roof flexibility, allowing each area to be optimized for its specific function within a single unified structure.
2Device complexity
If one piece of glazing covers both windscreen and roof, then aerodynamic and optical integration is improved, but uniform mechanical properties cannot satisfy both areas
Solution Approach 1:
The patent applies parameter changes by varying the storage modulus G' across different regions of the interlayer film. The first region has a storage modulus of 50-500 MPa while the second region has a storage modulus of 10-200 MPa, allowing the single piece of glazing to provide different mechanical responses for windshield and roof areas respectively.
Solution Approach 2:
The interlayer film functions as a composite material system where a polyvinyl acetal resin base polymer is combined with plasticizers in different proportions across regions. This composite approach enables continuous adjustment of mechanical properties within each region while maintaining the integrity of the single-piece glazing structure.
3Strength
If interlayer film has high storage modulus, then windscreen protection is improved, but roof flexibility and pedestrian safety are compromised
Solution Approach 1:
The interlayer film implements local quality by providing a first region with high storage modulus (50-500 MPa) for windscreen impact resistance and a second region with lower storage modulus (10-200 MPa) for roof flexibility. This spatial differentiation allows the windshield area to protect against pedestrian impacts while the roof area can flexibly respond to rollover forces.
Solution Approach 2:
The interlayer film is segmented into functionally distinct regions: a first region for windscreen application with optimized mechanical properties for pedestrian protection, and a second region for roof application with optimized properties for rollover protection. This segmentation enables each area to independently fulfill its specific safety requirements within the unified glazing structure.
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
Enables the production of laminated safety glass that meets specific mechanical and adhesion requirements for windshields and roofs, enhancing aerodynamics and optical integration while maintaining necessary safety standards.
Implementation Method 1
different mechanical properties defined as average storage modulus G' at 1 Hz, 3 K/min and 50 °C measured according to the method described in the description
Data Source
Figure 1~2
AI summary
The invention is directed to an interlayer film comprising at least two areas A1 and A2 having mechanical properties wherein each area comprises at least one layer L1 and at least one layer L2, each comprising a mixture of polyvinyl acetal resin and at least one plasticizer characterized in that the at least two areas A1 and A2 comprise different layers L1 and L2 to provide the at least two areas Al and A2 with different mechanical properties defined as average storage modulus G' at 1 Hz, 3 K/min and 50 °C measured according to the method described in the description and wherein the average storage modulus G' of area A1 is at least 10% higher than the average storage modulus G' of area A2.