First off, what is environmental exposure testing?
Environmental exposure is the process of subjecting a part or material to a set of predefined conditions for a given duration. By exposing your product to these conditions, you can assess its durability under similar conditions. Environmental exposure is an ever-growing field of testing constantly adapting to new industry and consumer needs. Our goal here at APM Testing is to help our clients choose the best exposure and testing options for their unique needs.
Why is environmental exposure testing so important?
Environmental exposure can also be referred to as accelerated aging or accelerated weathering. This is because the parameters that the material will be exposed to are more severe than typical environments they may see in actual use. This allows potential effects/failures/degradation that could be seen after years of service to be observed in weeks or months of exposure time.
Most of our clients are looking into environmental exposure testing for one of several reasons:
- To meet a particular material specification or requirement defined by a customer.
- To compare their product against a competitor’s for product development or marketing.
- To evaluate a potential new supplier/vendor against their existing sources.
In general, environmental exposure testing is an investment to reduce the risk of product failures in the future by testing today.
What types of environmental exposure tests are available?
The number of different types of exposure testing available today is far too extensive to include in one article, but we will touch on the most requested types of tests and equipment.
Temperature/Humidity (Cycling):
Extreme temperatures can wreak havoc on materials and the end function of products. Add in water, in the form of humidity or immersion, and the detriments can be further compounded for certain materials. To simulate this, a temperature and humidity chamber can be used.
Test Methods: ASTM D573, ISO 188, ASTM D3012, ISO 4577, ASTM D865, ASTM D1151
Salt Fog:
Corrosion resistance is a highly desired property, especially with metal components. Salt fog exposure methods (ex. ASTM B117) are the gold standard when it comes to simulating corrosive environments. Our chamber exposes products to a continually monitored salt fog that accelerates corrosion.
Test Methods: ASTM B117, ASTM D610, ASTM D714, ASTM D1654
Weathering:
UV or Xenon arc exposure is often referred to as accelerated weathering. These chambers are designed to simulate outdoor exposure conditions such as daylight, elevated temperature, and humidity. This process can be combined with cooling and darkness cycles to simulate real-world day/night exposure.
Test Methods: ASTM G154, ASTM D4329, ASTM G151, ASTM G155, ISO 4892, ASTM D4587, ASTM D4459, SAE J 2527
Fluid Exposure:
Fluid/chemical exposure assesses the performance of a product after contact with a specific material, such as cleaning supplies, gasoline, grease, brake fluid, etc. This testing is particularly important for rubber O-rings, gaskets, or plastic containers.
Test Methods: ASTM D543, ASTM D570, ASTM D471
What’s next?
After exposing the material to the chosen conditions, the sample needs to be evaluated. The evaluation methods used should be based on important material properties for its end use. For example:
- Material used for a sign may be evaluated for change in color or gloss.
- Plastic used in outdoor furniture may be evaluated for changes in mechanical strength.
Summary:
When looking into exposure testing, remember to consider your product’s end use to find the best test method, test duration, and evaluation method. Is your material going to be used indoors and subjected to routine cleaning? If so, exposure to cleaning fluids may be best. Is your product left out in the elements? Then, accelerated weathering or temperature/humidity cycling would be better.
We hope you have found this brief introduction to environmental exposure testing helpful. If you are interested in performing these types of tests, or if you have any questions, please reach out to us here at APM Testing.