NBR moulded parts for oil seals in the automotive sector

Carbon blacks are often selected as (functional) fillers, when it comes to oil resistant NBR compounds for sealing parts - be it in mechanical engineering or automotive. When considering the compound composition, an inactive carbon black, such as the thermal black N990, often is responsible for the fine tuning of the mixture and to better meet or meet at all the requirements for such sealing parts, as they are stated exemplarily in the ASTM D2000. Since the price for carbon black strongly fluctuates depending on fossil raw materials and in the long term the price is expected to rise, a possible cost-effective alternative would be desirable. Therefore, this article focuses on replacing N990 with Neuburger siliceous earth variants and examines to what extent these substances are suitable as a replacement material without impeding to fulfil the standard requirements. In particular, changes of mechanical properties and of chemical resistance are discussed. In summary it can be noted that thermal black N990 can be exchanged with various siliceous earth products, and the latter even allow further customisation and/or cost optimisation.