hose reinforced with plastic rod 1

[mariobed]

Does anybody know a good plastic rod and supplier to reinforce a rubber hose to make it crush resistant. We tried some PET and PBT resins but we have still not found the good one yet

Thank you

 

[patprimmer]

I am sorry, but your question is hard to understand. Can you please explain in clear language.

What exact function do you require of the plastic.

How did the polyesters fail.

How will a rod make the hose crush resistant without blocking all the flow through the hose?

Is the plastic only required as a mandrel for manufacturing the hose?



Regards
pat

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[mariobed]

Hi Patprimmer,
Usually a rubber suction hose is reinforced with steel helix wire to handle vacuum, the problem with steel is if the hose is crush the hose become unusable because the hose will not go back to its original shape. We are working to do a rubber suction hose reinforce with plastic helix wire that will handle full vacuum and if the hose is crush the hose will return to its original shape and still be usable.

We are currently using a 3mm PBT rod that is good but we want to use a smaller diameter rod to lower the cost. Our rubber hoses are steam cured for 60 minutes at 62psi (307F). Some PET and PBT resins we tried become brittle after curing and other ones are not stiff enough.

Thank you

 

[patprimmer]

Polyesters are particularly prone to hydrolysis, especially under alkaline conditions. PET is worse for this than PBT.

Styrene modified PPO has very good hydrolysis resistance (most common source is Noryl from GE). I am not sure about it's flex modulus vs PBT though.

Another posibility is Glass Filled Nylon.

It will have the required flex mod, and more if you require it. It is still susceptible to hydrolysis, but not nearly so much as polyester. Hydrolysis resistance grades are avaliable and used as automotive radiator header tanks. These grades are avaliable from DuPont, Bayer, BASF and Solucia? or whatever the old Monsanto call themselves now.

Regards
pat

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.