Stability of sealants when exposed to UV radiation, temperature and moisture

Adhesives and sealants for the transport industry may be exposed to a wide range of extreme climatological conditions during their lifespan, such as very high or low temperatures, humidity, water, ice, salts and, of course, harmful UV radiation.
SABA has elaborate facilities for conducting accelerated ageing tests, whereby we simulate extreme conditions to gain faster insight into the long-term effects of these conditions. One of these tests specifically focuses on UV radiation and high temperature. We work closely together with an external testing institute, Q-Lab in Arizona (USA), for this purpose. In addition, SABA has access to QUV cabinets in its own laboratory, where we test the effects of UV radiation and moisture.
We are happy to share more information about the crucial role played by these tests, the way in which the tests are conducted and the results.

Michel Menting
Author Michel Menting Technical Product Manager
Why is UV resistance crucial?

UV radiation can do a lot of damage to a sealant. This includes, discoloring, fading, cracking, fissuring, blistering, loss of strength and oxidation. UV-resistant adhesives and sealants are of crucial importance to the transportation sector for various reasons, including:

  • Safety: vehicles must be strong and safe. When sunlight degrades a sealant, this can endanger the structural integrity of the vehicle. A sealant that is UV resistant helps prevent leaks, loose panels and other damage that can affect the safety of passengers.
  • Aesthetics: Because vehicles generally are exposed to sunlight, their color and appearance can be adversely affected. A UV-resistant sealant helps maintain the vehicle’s aesthetic quality, as a result of which it looks new longer.
  • Durable: A vehicle that is bonded and sealed with a UV-resistant product will last longer than a vehicle that is not. It prevents the vehicle’s seals and bonds from degrading and weakening. This extends the vehicle’s service life and minimizes maintenance costs.

Testing at Q-Lab in Arizona

As mentioned above, SABA tests its sealants at Q-Lab in Arizona, one of the world’s largest desert exposure test facilities. Because of the intense solar radiation, high temperatures throughout the year and dry climate, Arizona is internationally known as a leading benchmark site for exposure to outside air weather conditions. Temperatures can be as high as 46ºC in summer. Tests here are conducted in accordance with the ISO 17025.
At SABA we produce samples of our own products, as well as those of competitors, that are then sent to Arizona. Here they are exposed to intense sunlight, photographed and optically evaluated by Q-Lab. Every three months we receive an evaluation report about the submitted samples, prepared by an independent expert. This report is valuable for collecting more knowledge about our sealants and how they perform in comparison to competitive products.

Testing with QUV cabinets

SABA has QUV cabinets in its own laboratory. These cabinets are specifically designed to reproduce conditions such as sunlight, rain and dew. This makes it possible to measure the impact of UV radiation combined with moisture. The condensation system inside the QUV cabinet provides a realistic simulation of dew and accelerates this process by increasing the temperature.
The QUV tester operates fully automatically, 24 hours per day, 7 days per week. In just a few days or weeks, this tester can reproduce conditions that cause damage, which, normally speaking, would take months or years in the outside air. To simulate outdoor ageing, materials in the QUV tester are exposed to controlled cycles of UV radiation and moisture at elevated temperatures. These tests are conducted in accordance with the ASTM G154 standard at a UV load of 0.89 W/m2 at 60°C.

How do our products perform?

To find out how the sealants in our Sabatack® product range and competitors’ products perform under the influence of UV radiation, tests were conducted in Arizona, as well as in a QUV cabinet. In this article we share the most striking results of these tests.

Arizona test results

The climatological conditions in Arizona lend themselves extremely well for intensity tests on our sealants and those of our competitors. Every three months, the sealant samples submitted by us are evaluated and photographed by an independent expert. The samples were evaluated on the basis of the following criteria:

  • Color
  • Gloss
  • General optical properties (general impression, chalking, contamination)
The photos give us a clear picture of how our sealants (also in comparison with competitors’ products) perform under extreme climatological conditions in Arizona. In the video we compare our Sabatack® 750 with other products used in the market: a polyurethane adhesive, polyurethane sealant and two MS polymer products.
If you would like additional information, we are happy to tell you more about the test results in a personal meeting. To make an appointment contact our adhesive and sealant specialists.


QUV cabinets test results

SABA, with the help of QUV cabinets, has rigorously tested the stability of its sealants, as well as those of competitors, using key criteria, including:

  • Color
  • Optical degradation
  • Fissuring/blistering
  • Oxidation
In contrast to the usual 1,000-hour testing period, we conduct the tests until there is visible damage. The test consists of two steps. In the first step, the samples are exposed to a UV load of 0.89 W/m2 at 60°C for 8 hours. In the second step, the UV lamps are extinguished and a moisture load at 50°C is simulated for 4 hours. These two steps are repeated until there is visible damage.
For example, a competitor’s white PU adhesive tested exhibited degradation after 291 days, while our white Sabatack® 750 only displayed damage after 803 days. These results provide us with direction for constantly improving our products.

If you would like to receive additional test results, do not hesitate to contact us.

Sabatack®: UV-resistant sealants

From the test results we can conclude that Sabatack® 750, as well as other products in our Sabatack® product range, are highly UV resistant. The fact that they held up well under full sun in the desert, combined with the QUV test results, shows that they are also highly UV resistant under less extreme conditions.

Go to Sabatack® products