PC/ABS molded-in stress quick check 1

[JoelMyers]

I am using PC/ABS for a plating application would like to check the molded-in stress of the part by a process similar to the following.

ASTM D 1939-84, "Determining Residual Stresses in Extruded or Molded Acrylonitrile-Butadiene-Styrene (ABS) Parts by Immersion in Glacial Acetic Acid"

I am not sure which acid I need to use for PC/ABS. Any help will be appreciated.

Thank you.

 

[gambro]

For PC/ABS Blends the following test media are recommended :

Methanol:Acetic Acid ratio 3:1
Methanol:Ethyl Acetate ratio 3:1
Toluene:n-Propanol ratio 1:3

We use Toluene:n-Propanol with good results, for ABS, PC and ABS/PC-Blend.

Take care on safety precautions (gloves, goggles) when handling Toluene. Keep the bath closed when not in use. Also, check your immersion bath mixture regularly (at least once per week), for example by refraction index, because the Toluene part of the mixture has the tendency to evaporate and thus the mixture will be diluted.

 

[mechintern]

Is there any specification about the concentrations of acid that should be used? Any response would be appreciated. Thanks

 

[gambro]

As I wrote, we use a mixture of 1 volume part "pure" toluene and 3 volume parts "pure" n-propanol. The other two mixtures with methanol we don't use ourselves. I got them out of the technical literature. Sorry, but in the cited literature there is no indication on the purity of these chemicals, the acid or otherwise.