EPDM used in vacuum hose?

[Moneil]

We recently used some Vacuum Tubing acquired from Napa in a damping test on one of our dosing units. The material worked great. I did some research and found it to be EPDM type P tubing. I have had no luck in finding out what specific type of EPDM was used in this tubing though. I need some physical properties of the material so that I have a baseline to work from when designing a producible product. The only physical properties listed are a min temp of -40 F and a max of 257 F. It also meets J1037 & J9426 SAE specs and has a 25 psi working pressure (5/32" ID tube). Do you know what type of EPDM this could be? Or possibly some more properties? Any information would be greatly appreciated.

 

[GrahamBennett]

I have not seen either of the SAE pecs you mention but I would assume that the hose is made from a suitably compounded extrusion grade of EPDM. Examples of these are Keltan 578Z or 778Z from DSM and Vistalon 7500 from Exxon/Mobil. Chemical analysis (TGA/FTIR, ash analysis, acetone extraction, glass plate chromatography) of the hose will give you a very close approximation of the formulation used.

 

[swall]

I would suggest that you first identify a potential supplier and then use their expertise to write a spec. One thing to keep in mind about extruded tubing is that it will contain plasticizers and other extrusion aids in addition to the base polymer and carbon black, etc. These all have to be identified when the spec is written so that no change can be made without your approval.