Rubber Manufacturing

[jdm2008]

I have some rubber in a system where I noticed a yellow color on the rubber inside and also on place surrounding it. I noticed this after a long period of time(it was not there when the system was first made). My research indicates this may be sulfur. The rubber I have will be used in an application with human contact and as I understand sulfur is an irritant, so this is not acceptable for us. The rubber is supposed to be neoprene and latex free. Is this the manufacturer's error? Has anybody had any experience with type of problem?

 

[trekshop]

Hello. The iron oxide coating (yellow) may have failed or oxidation may have occurred
due to exposure to moisture. One possible solution is to put water-absorbent (silica-gel?).
Just try.



Allan S. Hugo, Ch.E.
Editor, ChemBookStore
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[jdm2008]

Thanks for your response. I am more concerned with pinning down the irritation cause to the rubber bag(or not). What will happen when the iron oxide coating fails, same with oxidation? Will this cause oxidation?

 

[jdm2008]

Will either of these create a irritating substance to be exposed on the rubber?

 

[ornerynorsk]

The first step is to verify exactly what material it is that you have. The manufacturer should provide an MSDS and/or a technical data sheet at the minimum. Then you can proceed to pinpoint what might be causing degradation or residue.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[ultrasonicprocessing]

You mention that you have "Some rubber" in the system but I will asume that it IS a rubber compound.
Since the problem shows on the surface after a period of time it is a migration problem.
1. Change to a non-sulfur based vulcanising agent.
2. Migration is naturally a liquid to surface migration but not physically noticeable. You only need a few percent to cause a problem.
3. Check your compound for possible migratory substances and change to non-migratory substitutes.
4. The migrating compound could carry(due to prefered solubility in the migrating material)the coloured material to the surface. could well be Sulfur but check for other materials that may have a yellow tone. i.e.Plasticizer migration is often over looked in PVC compounds.

Nobody said it would be easy. Ken.