Laminated Glazing Intumescent Layer Positioning for Bullet Resistance
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Solution Overview
Problem
Existing laminated panes struggle to provide both effective fire protection and bullet resistance according to standards EN 1063, as the intumescent layer can become a weak point upon impact, leading to breakage and uncontrolled splinter release.
Innovation Solution
A laminated pane design with a front pane, an intermediate pane, and a fire-resistant glazing unit where the intumescent layer is positioned behind the geometric center plane, combined with a plastic lens and polyurethane composite layers to absorb kinetic energy and prevent splinter escape, ensuring dual functionality post-impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the intumescent layer is positioned in the conventional location (near the front pane), then fire protection is provided, but the layer becomes a weak point upon impact causing breakage and splinter release
Solution Approach 1:
The patent repositions the intumescent layer from the conventional location near the front pane to a position behind the geometric center plane of the laminated pane. This spatial reconfiguration places the fire-resistant glazing in the rear half of the laminate, away from the direct impact zone, thereby removing it from the primary impact path while maintaining its fire protection function.
Solution Approach 2:
The patent introduces a plastic lens (polycarbonate or PMMA) positioned between the front pane and the fire-resistant glazing. This intermediate element absorbs kinetic energy from projectiles, preventing direct impact on the intumescent layer and fire-resistant glazing, thereby avoiding the creation of weak points and uncontrolled splinter release.
2Temperature
If fire-resistant glazing is used with intumescent layer, then heat insulation is improved, but the structure fails upon projectile impact
Solution Approach 1:
The fire-resistant glazing is repositioned to the rear half of the laminate structure, behind the geometric center plane. This spatial relocation protects it from direct projectile impact while maintaining its thermal insulation function, as it remains positioned between the front pane and rear cover pane where it can perform heat insulation without being the primary impact target.
Solution Approach 2:
The patent creates a composite structure combining glass panes, plastic lens (polycarbonate or PMMA), and fire-resistant glazing with intumescent layer. This multi-material composite design distributes impact forces across different materials with complementary properties, allowing the structure to maintain both thermal insulation and impact resistance.
3Reliability
If multiple glass panes with intumescent layer are combined, then fire protection is achieved, but manufacturing complexity increases
Solution Approach 1:
The laminated pane is segmented into distinct functional layers: front pane, plastic lens, fire-resistant glazing with intumescent layer, and rear cover pane. Each segment performs a specific function, and the modular structure allows for standardized manufacturing processes for each component, reducing overall manufacturing complexity despite the multi-layer construction.
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 solution achieves enhanced bullet resistance and maintained fire protection by positioning the intumescent layer away from direct impact, allowing the composite pane to remain structurally intact and prevent splinter escape, meeting higher EN 1063 classifications.
Implementation Method 1
The fire-resistant glazing has at least one intumescent layer (14.1) that foams up in the event of a fire and has good heat-insulating properties
Implementation Method 2
the material that forms the intumescent layer foaming with an increase in volume and a decrease in density
Implementation Method 3
The lens consists of a plastic material. This prevents splinters from escaping from the rear, so that a high level of protection in accordance with EN 1063 is possible
Data Source
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AI summary
The plate (20) has a wind screen (10) that is provided with attack side (A) and fire protection glazing portion (14). An intumescent layer (14.1) of attack side is arranged behind the geometric center plane (m) of main portion. The center plane of thrust washer (17) is placed behind the fire protection glazing portion. The fire protection glazing portion is made of plastic material comprising polyvinyl butyral, polycarbonate and polymethyl methacrylate. The intumescent layer is made of alkali silicates and aqueous acrylic polymer.