Buna N vs. NBR
Buna N vs. NBR
(OP)
In regards to using NBR as a replacenent for Buna N in small motors, are there any significant differences that could affect performance. My company uses Buna N, but our new plant in China does not have it available. The research I have done seems to suggest the two are interchangable and that Buna N is just the old name for NBR. However, if that is the case, why are they having a problem? If the percent of acrylonitrile is the same, is this essentially the same material? Any help would be appreciated, thanks.





RE: Buna N vs. NBR
RE: Buna N vs. NBR
RE: Buna N vs. NBR
The biggest influence will in the formulation the base is used in. We have dozens of NBR formulas that we use for select applications. Most formulations have 10-20 other ingredients in them that very much influence part performance. In very broad terms, in addition to the base co-polymer (may be one or more of the more than 200 commercial grades available) they will have the filler system (re-inforcement, low/high temp plasticizers, etc), protectants (antioxidants, antiozonants), process aids and the very influential cure system (sulfur based, sulfur donor based, accellerators, peroxide based/co-agent).
In short no two 35% ACN NBR formulas are the same and they will range from exactly what the application calls for to complete failures. I suggest that you get down to specifics of formulation as well as material properties specifications with your suppliers.