Resistance of gums and thermoplastic rubbers to ageing

Resistance to ageing in ozonated air

A rubber or thermoplastic rubber’s resistance to cracking when subjected to static or dynamic stretching strains is assessed in air at a specified temperature, humidity and concentration of ozone, with the direct action of light being eliminated. The ozone chamber with a working volume of 310 litres also permits tests on non-rubber materials to be carried out, at a wide range of ozone concentrations: from 25 to 1000 pphm.

Testing norms

  • PN-ISO 1431-1
  • ASTM D1149
 

Devices

  • Anseros SIM6300-TH ozone chamber
  • 400/130 AB/DU-Oz ozonometer
 
In the photo: The inetriour of the ozone chamber with devices for static and dynanmic testing.

Rubber – determination of resistance to the action of liquids

The resistance of rubber and thermoplastic rubbers to liquid is evaluated by determining their properties before immersion in the test liquid and then after removing them from the liquid (thus determining the change in mass, change in dimensions, change in surface area, change in hardness, change in tensile properties). The test liquids are commonly used working fluids, such as: petroleum derivatives, organic solvents and chemical reagents, as well as reference test fluids. Samples are immersed in the selected liquid for a specified time at the selected temperature.
 

Test norm

  • PN-ISO 1817
 

Devices

  • Thermal chambers: Heraeus, POL-EKO

Rubber and thermoplastic rubber – accelerated ageing and heat resistance tests

Samples for testing are tested in a controlled way by the action of air at elevated temperature for a certain period of time. The physical properties are then determined (e.g. tensile strength, stress at medium elongation, ultimate elongation, hardness) and values compared to the same properties of test specimens that have not been aged.
 

Test norm

  • PN-ISO 188
Document No. Title/Description
PN-ISO 188 Rubber, vulcanized or thermoplastic -- Accelerated ageing and heat resistance tests
PN-ISO 1817 Rubber, vulcanized or thermoplastic -- Determination of the effect of liquids
PN-ISO 1431-1 Rubber, vulcanized or thermoplastic -- Resistance to ozone cracking -- Part 1: Static and dynamic strain testing
ASTM D1149 Standard Test Methods for Rubber Deterioration—Cracking in an Ozone Controlled Environment