NDS Seals

The properties of the final product are mainly determined by the properties of the compound. Before starting the production of the final products the compound is tested to guarantee the correct properties. This is a standard procedure in our production facilities.


A rheometer test is carried out on every single batch of compound.

The Rheometer describes precisely and quickly curing and processing characteristics of vulcanizable rubber compounds. It works on a very simple principle. A test piece of rubber compound is contained in a sealed test cavity under positive pressure and maintained at a specified elevated temperature. A rotor is embedded in the test piece and is oscillated through a small specified rotary amplitude. This action exerts a shear strain on the test piece and the torque (force) required to oscillate the disc depends upon the stiffness of the rubber compound. The stiffness of the specimen compound increases when cross links are formed during cure. A plot of this torque (force) value against time gives a typical graph called Rheometer curve. The cure curve obtained with Rheometer is a finger print of compound's vulcanization & processing character.


Of course hardness and tensile strength are also checked for every batch.

When all values are within the allowed parameters the compound is released for production.



NDS-Seals B.V. - Gentiaan 2a - 1787 CM Den Helder - Tel: +31 223 714 100 - Fax: +31 223 714 119 - e-mail: info@ndsseals.com