Hello all,
Was recently asked to perform a failure analysis on some O-rings, which appear to have suffered from extrusion and cracking damage.
An incorrect material was suspected to be the cause of failure - as a result, two ring samples were sent for analysis, a failed ring and an OEM (presumably correct) one.
The results of the analysis showed them both to be butadiene nitrile rubber, although the failed rubber sample contained aniline and methylaniline as additives, while the OEM sample contained quinolines & nonylphenols.
Now its all well and good to say that the incorrect material was used, but did that contribute to the failure? Some preliminary googling on the additives revealed the following.
- quinoline is an antioxidant, and helps prevent degredation
- nonylphenol is a plasticiser, and reduces 'brittleness'
- the aniline compounds are vulcanisers (make the rubber more resilient?)
I suspect the absence of quinoline might be contributory to failure, but I wasn't sure if the aniline acted as an antioxidant.
Anyone have any further advice?
Thanks in advance
Was recently asked to perform a failure analysis on some O-rings, which appear to have suffered from extrusion and cracking damage.
An incorrect material was suspected to be the cause of failure - as a result, two ring samples were sent for analysis, a failed ring and an OEM (presumably correct) one.
The results of the analysis showed them both to be butadiene nitrile rubber, although the failed rubber sample contained aniline and methylaniline as additives, while the OEM sample contained quinolines & nonylphenols.
Now its all well and good to say that the incorrect material was used, but did that contribute to the failure? Some preliminary googling on the additives revealed the following.
- quinoline is an antioxidant, and helps prevent degredation
- nonylphenol is a plasticiser, and reduces 'brittleness'
- the aniline compounds are vulcanisers (make the rubber more resilient?)
I suspect the absence of quinoline might be contributory to failure, but I wasn't sure if the aniline acted as an antioxidant.
Anyone have any further advice?
Thanks in advance