When using a new polymeric material, the customer must check whether if it has undergone weather testing. The process of weather test is a controlled degradation under natural or laboratory conditions of a polymer.
Polymer systems: for an every day use
Some polymer systems are meant to protect facilities against degradations caused by natural phenomena when they are in direct contact with them. These degradations include UV radiation, humidity, high temperature and temperature variations. Yet, both natural and synthetic of this macro-molecule play an essential role in every day life: painting, coating, plastics, amongst the others. Improving the quality of the product is therefore an every day challenge for manufacturers and scientists. They try to balance durability and the expected shelf life determination of polymer systems by using every possible means, in particular real-time tests.
Why is testing crucial?
Weather testing has become an unavoidable step to avoid product failure. This implies an extensive knowledge of where and how polymer should be used. On the other hand, producers must enhance product performance while reducing costs of production. Now, the solution lies in new materials and new additives. However, working with these new and unknown materials without suitable testing explains the rise of the weathering-related defect rates. Most of the time, polymers are used in markets they have not been designed for. To correct this, one manufacturer tests samples to several locations in the world, because the viscoelastic properties and sensitivities of the product are surprisingly different according to the local environment.
Methods of test
There are three main methods for polymers test. The
natural weathering consists to place some specimens on racks, focused at the sun or the wind directions. This outdoor testing usually use a humid tropical area site, which maximum temperature, UV intensity and humidity. Florida (United States) is the world standard for this kind of testing. Despite theses conditions, this outdoor testing requires several years, before concrete results are witnessed. Therefore, scientists proceed to an accelerated natural weathering test, to speed up the process. The samples are still placed outdoor, but with using devices like mirrors (such a
Fresnel-reflecting mirror), or a technology allowing the specimens to come along the sun rotation. Finally,
artificial weathering is an indoor test, involving a lab process highly accelerated within weathering chambers.