Non Wear rubber

[Wraith]

I have this application were I require a sleave over an inflatable device. The device is a Firestone Air picker.
This device inflates from a cylinder shape to a balloon shape.
The application I am using this device for is to pick up engine pistons from the sides by inflating the bladders one on each side of the piston and sqeezing the piston.
In test trials we ran 50000 cycles and the bladders did not show wear.
But when running in the machine the bladders did not last 1200 cycles.
From the damaged baldders in the machine we have noticed that all the bladders fail the same way by a small slice down the side of the bladder.
I would like to know if anyone has a material that can expand with this bladder and also be wear resistant,and cut resistant.
I really need help.

 

[prodeng]

You need to ask yourself why they didn't fail in the test. Was air pressure changed (more inflation in application), or did the test piece(s) have less of a sharp edge, and if so, why? Unless you get to the root cause of the puncture, you may only be masking the real problem. As for your search for a coating, I'm not a materials guru. Perhaps more definition would help (how much compression on the piston can be allowed? how sharp are the edges? certain materials forbidden to avoid contamination?).

 

[Wraith]

I have looked back throught the testing proceedure and all the steps involved are the same in the machine as in the test rig.
The only difference is that the pressure for the bladders could have been changed by some one in the machine with out anyone knowing. (Seems to be Very Likely)
As to the materials I was looking into surgical tubing on the basis that surgical tubing is very hard to puncture.
The only problem that I may have with the surgical tubing is that puncturing is not the main cause of failure, slow wear slicing is.
I have found that once the jacket for the bladder is sliced the inflation of the bladder rapidly tears the remaining jacket. The new slice acts as an exit for the bladder to push through when the main body of the jacket is inflated up against the piston.
I require a material that will inflate like a balloon but still be strong enough to resist slicing.
I have redesigned the machine to now inflate the bladders on a more flat and less sharp area.
I would still like a jacket that will put up with more abuse than the present jackets.
As long as the jacket does not leave any marks or deposits on the piston and will withstand mild machining fluids I think any material that can stop the slicing will work.
The bladders inflate from 1.25 to 1.75 so the material will have to be flexable enough for this.
Still need help.

 

[rhc]

Hi Wraith

Polyurethane elastomers are one of the better cut resistant elastomers and polyurethanes generally have excellent wear properties. you will need a low durometer with good stretch properties.