Testing the durability of plastics

Modern materials have to meet ever more specific requirements in order to meet the constantly increasing demands of increasingly specific applications. When it comes to durability testing, even computer-aided simulations reach their limits, so that an in-house test facility has been developed.

Standards: DIN EN ISO 4892, DIN EN ISO 22088, DIN EN ISO 175, DIN EN ISO 899, DIN 53438, DIN EN ISO 4589

Environmental simulation of plastics

Several factors are examined in the field of environmental simulation (EMS). Among the most important are resistance to moisture and sunlight or UV radiation. As a result of these influences, embrittlement or other effects can occur which drastically reduce the service life of the products. Furthermore, the plastics can discolor due to the decomposition of color pigments and thus lead to complaints. We can check all these influences by means of outdoor weathering or accelerated artificial ageing.

Testing chemical resistance

In industrial processes, the components used must be resistant to the process mediums with which they come into contact in this process. These include mainly lubricants, cleaning agents, acids, alkalis, solvents and gases. This resistance can be tested in our laboratory by specific ageing in the appropriate mediums and tests of the relevant properties before and after ageing.

Standards: Volvo STD 422-0005: 2009-06, Volvo STD 422-0006: 2010-04, ISO 16750-5: 2010-04, VW PV 3964: 2006-01, ASTM D471

Fatigue testing

If components are subjected to continuous mechanical stress in the course of their use, it is useful to test their fatigue strength in a creep rupture test. This allows creep or relaxation to be precisely described and the material and its design to be optimized for the respective application.

Thermal resistance test

If thermal stresses occur during use, plastics must have a corresponding temperature resistance or heat resistance. This can be investigated with the VICAT test device or thermogravimetrically using TGA. With TGA, the sample to be tested is heated to a specific temperature and the loss of mass is determined.

Depending on the test temperature, outgassing of fillers up to decomposition of the base material occurs. In the case of high temperature loads, it makes sense to carry out fire tests. These tests can be used to classify the flammability of plastics and determine the burning rate in the event of an emergency.

More detailed descriptions of the methods mentioned can be found under the following links:

Resistance to chemicals and mechanical stress

Chemical Compatibility according to ASTM D543

By means of this test the resistance of plastic materials is evaluated by exposure to various chemicals and defined mechanical stress. During the test, ASTM Type I tensile bars or IZOD-bars are exposed to chemicals for 7 days under controlled conditions. A portion of the samples is exposed to defined mechanical stress by means of a special fixture. Resistance is evaluated by change of weight, size or physical properties in comparison to unexposed specimens.