silver on ABS material

Do you mean you have metal ingression on the moulded part so after removal from mold you can see silver coloured particles in the bumbers?

Please explain with more detailed info for us to work with, I am sure somebody will know.

Regards

No I do not mean that. What I mean is silvery metallic appearance may have to do with effect of moisture absorption which may have caped reaction to form the clear mold and now is showing up as defect in the mold. Easy ways to test is to expose resin and hardener separately to 85 % humidity at 60C temperature and then use it and you will see that .You will see this effect more when you do the resin . This is temperature humidity effect

Masyood

so are you the original guest poster?

Now I am totally confused as we have 2 guests and you all talking in the first person which to me sounds like you are all the same person.

It appears you do not have correct hardener weight. In actual formulation it end purpose dictates the ration of resin, plasticizer and hardener. If you explain the end requirements I think there is company in India in Chennai will be able to guide you through. The company name is Global Applied Materials.

Masyood

That sounds interesting, I was not aware that incorrect hardener could result in "funny" deposits.

I was thinking along the lines of moisture in the granules before mixing and moulding. While some rubbers develop pockets of uncured rubber due to moisture. I know he is not working with rubber but I used to, so I compared it a little bit with that. We used to have to mix in a certain proportion of dehumidifying powder to get rid of the moisture before we could mix for moulding. The mixture would have to stand for a few days before we could mould.

I am interested now to see what it really is in the end. Hope the original poster comes back to us.

Guest,

Maybe you have checked: - Are you sure your dryer is functioning correctly, you may be out of desiccant. Also you should confirm by checking the moisture content in your plastic (moisture analyser). If you don't have an moisture analyser it would be a good time to ask your boss for the money for one.

Regards

Jon

in addition to checking the moisture content, are the parts being stressed during release from the mold?

If there have been recent revisions to the mold, perhaps you are seeing witness marks due to stressing of the part.

also check that proper cycles are being followed. Someone may be trying to artificially inflate productivity by pushing the cycle. if you eject while too hot, and the part has not properly set, you may may be absorbing excess moisture throught condensation in and around the part part and the tool.