Solar ageing testing verifies weatherability under outdoor exposure. Parts fitted at the dashboard, door mirrors, roof and similar positions are exposed to solar radiation and UV over the long term, which degrades material properties.
Ageing mechanisms
Photo-ageing: UV and visible light break molecular chains, lowering molecular weight and making the material brittle.
Thermal ageing: the high temperatures of solar soak accelerate oxidation.
Damp heat ageing: acts together with moisture, accelerating degradation.
In the real environment all three combine, and a single-factor test is unlikely to reproduce it fully.
Test methods
Xenon arc ageing: reproduces the full solar spectrum and can simulate daylight, temperature and humidity at the same time — the closest to the real environment.
Fluorescent UV lamps (UVA/UVB): predominantly ultraviolet, low cost and fast, suited to material screening.
Outdoor natural exposure: direct exposure outdoors is realistic but slow, typically requiring years.
Typical failures in automotive parts
Plastic parts discolouring or chalking → insufficient weatherability of the pigment or base resin.
Seals hardening and cracking → rubber or silicone not weather-stabilised, losing elasticity.
Coatings crazing and flaking → mismatch in thermal expansion between coating and substrate.
Labels and screen printing fading → insufficient light fastness of the ink.
Functional degradation: display contrast dropping after prolonged solar exposure.
Evaluation after the test
Appearance rating: colour difference, crazing, degree of chalking.
Mechanical property retention: change in tensile and impact strength relative to the initial value.
Functional test: display performance, key feel, seal condition.
Infrared spectroscopy or microscopic observation: depth of surface degradation.
Frequently asked questions
How long does xenon arc ageing take?
It depends on the cumulative radiant exposure the standard specifies and on the purpose. At the screening stage a shorter run can give a preliminary judgement; formal validation must reach the specified exposure. Light source, wavelength range and black-panel temperature control differ between standards, so severity varies a lot and cannot be converted directly.
Does the in-cabin dashboard position need ageing testing?
Yes, but note the difference between in-cabin and exterior environments. The dashboard sees solar radiation through the windows, so UV intensity is lower than direct exterior exposure, but temperatures can be higher. The actual exposure must be assessed per vehicle model and mounting position.
Service notes
Our laboratory holds both CMA and CNAS accreditation, covers about 10,000 m2 and runs more than 500 sets of equipment. All testing is carried out in our own laboratories — nothing is subcontracted. Plant visits and on-site witnessed testing are welcome.
Scheduling follows the actual project pipeline. You can state your preferred lead time when you submit samples; we will confirm a feasible plan against current capacity and keep you updated at each milestone. Once the report is issued we send the electronic copy; corrective-action advice can be arranged separately.
