Performance of Headlamp Lens Systems Durability
This SAE Automotive Lighting Materials Recommended Practice incorporates several test methods in order to provide performance requirements facilitating a more accurate assessment of headlamp lens systems (lens substrate plus coating(s) if applicable) durability versus the established practice.
Rationale: This SAE Automotive Lighting Materials Recommended Practice is intended to provide performance requirements that will be a predictor of lifetime performance for headlamp lenses on vehicles in the field. Current law requires plastic headlamp lenses satisfy 3 year outdoor weathering, which is performed on substrate plaques with coating combinations. Abrasion resistance is also a requirement that was included in order to justify plastic materials as a replacement for glass in headlamp lens systems.
These requirements were satisfactory when the nations vehicle fleet average was 5 to 6 years in service, now with a national vehicle fleet averaging over 11 years, the aforementioned tests do not accurately predict the durability of the headlamp lens system over its lifetime. Failure of the headlamp lens dramatically limits vehicle's primary night time safety system, increases glare toward oncoming motorists, and presents a significant hazard to pedestrians.