How UV Testing is Performed on Polymer Products and Plastics

To ensure that polymer products and components (such as plastic, fiberglass, painted surfaces, etc.) can endure the sun’s ultraviolet radiation throughout their intended lifespan without degrading or losing their normal qualities, UV testing is performed.

To achieve this, we may observe what happens to the polymer when we leave it in regular sunlight for a long time. When developing a new product, it is common practice to put some samples through accelerated UV testing in a UV testing lab, which simulates a prolonged amount of time under UV radiation bombardment in a short and practical timeline.

The procedure for UV testing in the laboratory

Sunlight-simulating lamps often use both ultraviolet-a (UVA) and ultraviolet-b (UVB) bulbs, with UVA providing the bulk of the energy.

To simulate years of exposure to UV light owing to accelerated testing, the items to be evaluated are placed in a QUV test chamber and left there for varying amounts of time. Here is an illustration of the range of available testing times at different facilities. 8 years of UV exposure can be mimicked in about 480 hours. The ultraviolet (UV) light test is designed to determine whether or not the plastic has lost any of its standard qualities, such as colour or impact, and flexural strength (exactly which qualities are evaluated is highly application-specific).

Keep in mind that the QUV chamber can also test for moisture and heat simultaneously with the main test.

Normalized procedures for testing

Since there may be subtle differences across standards, you should find out which one(s) the testing lab is using to ensure compliance. Listed below are some resources that may be of interest to you:

• Plastics should be exposed to fluorescent ultraviolet (UV) lamps, according to ASTM D4329-13.
• Fluorescent ultraviolet (UV) exposure of photodegradable plastics according to ASTM D5208 – 14.
• ASTM D4587-11(2019)fluorescent UV condensation exposures of paint and related coatings e1 standard practice
• ISO 4892-3:2016(en)
• The Use of Fluorescent UV Lamps in the Laboratory, Third Part Plastics
• Ed. 3.0 en:2018 IEC 60068-2-5
• Test S: Ground-Level Solar Irradiation Simulation and Solar Radiation Testing and Weathering Procedures
•  

This criterion also applies when compared to sunlight outdoors:

• A Standard Test Method (ASTM) D4364-13:Method for Accelerated Outdoor Weathering Testing of Plastics in Direct Sunlight