We as FIRAT use the most natural raw material, Ethylene Propylene Diene Monomer (EPDM) for seals on our PVC door and window systems. The reason is that EPDM seal is the single seal that has resistance to sunlight-air oxidation, ozone-induced cracks, shore hardness range of 30-95 at temperatures between +130 C -40 C and irreversible deformation values for sealing on the system under excessive wind pressure.


Another important aspect of EPDM seals is continuity of quality. Thanks to our supply of invariable raw material, full-automatic production feeding systems, mixtures prepared by computer aid and laboratories for conducting obligatory raw material and product test, FIRAT EPDM seals are always produced in the same quality and standards. We produce all our products containing sulphur and peroxide in accordance with the standards RAL GZ-716 / 1 Ab and TSE -7510. Under these standards, density, hardness, elongation at break and break strength and irreversible deformation of the seal are tested. We vulcanize EPDM seal in two ways, namely with sulphur and peroxide. Physical characteristics assured by means of vulcanization system by use of sulphur ensure that much less irreversible deformation is obtained at higher temperatures by vulcanization with peroxide.


Diameter, wall thickness, ovalness and similar production measuring is performed by means of ultrasonic measuring equipment available on the production lines an thus improper production is prevented by activation of audio and illuminated warning system in case of off-standard situations. Additionally, EPDM seal section is continuously magnified 10 times by use of our special projection equipment for performing measuring controls to the accuracy of 0.001. Produced with quality control system at all stages such as raw material, production and packaging and as integrated with PVC profiles, the seals are subject regular measuring controls on samples taken from each carton and archived.