ABS or Not?

[Geoff]

I'm still fairly new to 3d printing but have printed several things on my FFCP (mostly successfully and primarily in ABS)
I've just bought some yellow ABS on ebay which prints well at 230 extruder temp and 110 bed temp.
However it does not dissolve in acetone. The colour leaches out turning the acetone yellow and leaving a gooey lump of white material behind. I guess this means that the material is not ABS?? If not what is it likely to be?

Although I've had no problems so far with nozzle blockage and the like with the material, I'm a bit concerned that they may be around the corner. Am I becoming paranoid and worrying unnecessarily?

There are 2 ways they colour filament that I know of (probably a hundred ways.. but that I;ve encountered... )

1 - they actually use that colour pellet and filastrude it in that colour, and that's the sort that does not leech.

2 - They dye the plastic as it's being extruded. This is done usually when the filament was made from a neutral colour pellet (as its sort of clear in its 'natural' state) OR they used tonnes of recycled plastic, in which case it comes out as a grey mash , which they then dye the appropriate colour.

In the case of #2, it generally is because the filament was actually first extruded clear and then they dyed it during the process... Clear pellets of raw ABS are generally cheaper so often thats why they do it that way.

So yes it is ABS, try and extrude it at 200c and see what happens, if it wont extrude, then there is your definitive answer...