PET Windshield Barrier Stack for Abrasion and Impact Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current safety films for windshields lack durability and fail to meet ANSI Z26 standards for weathering, abrasion resistance, and impact protection, particularly when applied externally, leading to increased costs and safety concerns due to glass fragmentation and pitting.
Innovation Solution
A protective barrier comprising a stack of polyethylene terephthalate (PET) films with a hard coat and adhesive layer, designed to be affixed to curved substrates, which enhances abrasion resistance and impact protection while maintaining optical clarity and durability, including UV stabilizers to extend service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a soft plastic core is used in laminated glass windshields, then penetration resistance and fragment containment are improved, but abrasion resistance deteriorates due to easy abrasion and reduced visual acuity
Solution Approach 1:
The patent applies composite materials by combining a hard plastic outer layer with a soft plastic inner layer. The hard plastic layer provides abrasion resistance and protects the soft plastic core, while the soft plastic core maintains penetration resistance and fragment containment. This composite structure resolves the contradiction by allowing each layer to fulfill its specific function without compromising the other.
2Duration of action of stationary object
If glass is used for windshields, then abrasion resistance is improved, but safety deteriorates due to production of sharp fragments on impact
Solution Approach 1:
The patent uses flexible plastic layers instead of brittle glass. The plastic material does not produce sharp fragments upon impact, eliminating the safety hazard while maintaining adequate abrasion resistance through the hard plastic outer layer. This substitution of material type resolves the contradiction between abrasion resistance and fragment safety.
3Reliability
If polyester substrate safety films are mounted on exterior windshields, then impact protection is improved, but durability deteriorates due to embrittlement from UV exposure
Solution Approach 1:
The patent changes the material parameters by selecting a plastic substrate with superior UV resistance compared to traditional polyester. This parameter change in material composition allows the film to maintain both impact protection and extended service life when exposed to exterior UV conditions, resolving the contradiction between protection and durability.
4Adaptability or versatility
If opto-electric devices are integrated into windshields, then functionality is improved, but replacement cost increases by a factor of 10
Solution Approach 1:
The patent segments the windshield system into a permanent glass windshield component and a replaceable protective barrier film. The opto-electric devices remain integrated in the permanent windshield, while the removable film provides protection without requiring device recalibration. This segmentation allows the film to be replaced independently, avoiding the high costs associated with replacing the entire integrated system.
Data Source
AI summary
A protective barrier affixable to a curved substrate comprises a stack of two or more lenses, each of the two or more lenses including a polyethylene terephthalate (PET) film, a hard coat on a first side of the PET film, and an adhesive layer on a second side of the PET film opposite the first side. The stack of two or more lenses may have a modulation transfer function that exhibits a contrast value greater than 75% for a spatial resolution of one line-pair per 0.0003 radians at 65 degrees angle of incidence. Heat and pressure may be applied to conform the stack of two or more lenses to the shape of the curved substrate.