Transparent Polymer Window Armouring

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Solution Overview

Problem

Existing antiballistic window solutions are expensive, difficult to shape into curved forms, and heavy, making them impractical for widespread use, and replacing existing windows with special glass is laborious and limits shooting from the protected side.

Innovation Solution

Applying a transparent polymer layer with a strength of at least 2 MPa and thickness of 5 mm to the inner surface of windows, which solidifies in place, enhancing ballistic protection without detaching the window, and optionally attaching a thin transparent plastic sheet to the opposite side for added smoothness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If special antiballistic glass is used, then ballistic protection is improved, but cost and weight increase

Engineering Contradiction:

Improveballistic protectionVSAvoidwindow weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent applies a polymer layer (such as polycarbonate or polyurethane) to the inner surface of the window, creating a composite structure that combines the transparency and rigidity of glass with the ballistic resistance of the polymer material. This composite approach provides antiballistic protection without requiring the entire window to be made of heavy special glass.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent uses a flexible polymer layer applied as a thin film or coating on the window surface. This flexible layer can deform under impact to absorb projectile energy while maintaining window integrity, providing protection without the weight of rigid armour glass plates.

Inventive Principle:

Principle #30Flexible shells and thin films

2Ease of manufacture

If armour glass plates are made flat, then manufacturing is simplified, but shaping capability is reduced

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidcurved form capability

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The polymer layer applied to the window can be formulated and applied in a manner that allows it to conform to curved or irregular window surfaces. This flexible coating approach enables shaped windows (including curved forms) to be armoured without requiring complex manufacturing processes for each specific shape.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If existing windows are replaced with special glass, then ballistic protection is improved, but installation complexity and cost increase

Engineering Contradiction:

Improveballistic protectionVSAvoidinstallation complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The polymer layer is applied to existing windows in their installed position, allowing the window to remain part of the object throughout the process. This preliminary application to the installed window eliminates the need to remove and replace entire window assemblies, simplifying installation while maintaining ballistic protection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The polymer layer serves as an intermediary substance applied to the existing window surface, providing ballistic protection without requiring replacement of the original window. This intermediary coating approach allows retrofittment of protection to existing structures.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If a thick polymer layer is applied, then ballistic protection is improved, but transparency and aesthetics are reduced

Engineering Contradiction:

Improveballistic protectionVSAvoidwindow transparency

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent specifies a controlled thickness range for the polymer layer (at least 5 mm according to the claims) and selects polymer materials with appropriate optical properties (such as polycarbonate or polyurethane with high light transmission). By optimizing these parameters, the solution achieves ballistic protection while maintaining acceptable transparency and aesthetic appearance.

Inventive Principle:

Principle #35Parameter changes

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 polymer layer improves the antiballistic performance of windows by supporting the glass, allowing shooting through while maintaining protection, reducing fragment ejection in blasts, and preventing blast waves from entering, thus enhancing multi-hit capacity and reducing casualties and collateral damage.

Implementation Method 1

applying a transparent polymer layer to a surface of the window, wherein the strength of the polymer layer is at least 2 MPa and the thickness of the polymer layer is at least 5 mm, wherein the transparent polymer layer is applied while the material for forming the layer is fluid, after: which the material is allowed to solidify

Methodology Applied

Scientific EffectPhase change (solidification): Phase Change

Data Source

PatentEP2084360B1Method for armouring a window

Publication Date: 2017.12.06 NEDERLANDSE ORG VOOR TOEGEPAST NATUURWETENSCHAPPELIJK ONDERZOEK TNO

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AI summary

The invention relates to a method for armouring a window of an existing object comprising applying a transparent polymer layer to a surface of the window. The layer is usually applied to a surface facing the inside of the object. In particular, the invention may be employed to a conventional glazing of a building or vehicle.