ABS not truly dissolving in acetone, is it ABS?

I made some abs juice and the filament did break apart into very small particles, but it separates within minutes.
Its real pure acetone straight from home depot, no question there.
The juice seems to work though, leaves the haze and makes the prints stick.

I am wondering if I have ABS, because I am having printing issues where the second layer does not stick well to first.
I am printing at 250 deg with a J head on a prusa I3.
I tried a few other temps down to 220 deg. The first layer is great, then others have adhesion issues.
The perimeters are actually decent, so it seems like the infill is not as good because the head moves faster.
I am at 30mm/sec for perim, 60 for infill.

I am wondering if this lack of adhesion might be due to junky filament. I got it on ebay for $25 a kg so its cheap.

I can print PLA nicely, its just ABS that I cannot seem to figure out the settings for.
Does this sound familiar to anyone?

Edited 1 time(s). Last edit at 03/24/2014 03:12PM by jmaeding.

What is left over may be pigment from the ABS. Every brand and color of abs is a little bit different.

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but the acetone is clear, so makes me think its only a poor suspension, not actually dissolving.
anyway, thx for the reply.

It could be other plastics mixed in with the ABS (a bad thing meaning cheap ABS).
It could be the acetone is over saturated (too much ABS already) how much did you put in? In an 8oz bottle I put about 6" of 3mm filament. I always use "natural" (no color) so it does not add color to the bottom of prints.
It could be color pigment as Jztopa mentioned.

On mine it looks like very watery milk, semi translucent. It it sits for a week some ABS settles to the bottom in a ultra fine powder but a single shake brings it back to suspension.

I probably put about 8" 3mm filament in 4 oz acetone.
So likely saturated, but its black filament so I was expecting some coloration of the acetone.
Its as clear as gin though.
I am thinking of talking to the supplier, so want to check what normal behavior is.

This would be a good rule of thumb test to make suppliers think about.
If we can make that like an industry standard test, then we could catch people selling bad filament quickly and have time to return product.

Edited 1 time(s). Last edit at 03/24/2014 05:37PM by jmaeding.

I did the same thing with Black ABS from monoprice. It looked like it broke down in the acetone, but there was no color change in the solution. Leaving the pieces over night left a melted black piece on the bottom of the jar. I thought maybe it was the Lowes/Home Depot acetone, but I did the same test with gold filament from another supplier and it dissolved just as tmorris9 describes.

Additives may affect results. For example: flame retardants can mask the polymer material's normal flame & smoke burning characteristics.
Black plastic is typically the lowest quality, avoid using it if you can.

PLASTICS AND ELASTOMERS IDENTIFICATION CHART
[www.consultekusa.com]

PLASTIC MATERIAL BURN TEST CHARACTERISTICS
[www.modernplastics.com]

Black ABS is full of all sorts of recycled junk (more correctly known as regrinds). It is masked by the black pigment.
Also old car parts made of ABS are now recycled.

Contaminates is what clog's a nozzle.
Clean unused regrind directly from the extruder, or injection mold is acceptable, and does not affect the resin.

The reason black plastic has a higher probability of clogging a nozzle is because it's easier to
hide, or add contaminates such as dirty resin, toxic waste by products, and cheap fillers into the black resin.

Regrind
Regrind materials include ground or chopped flash, runners, sprues and non-contaminated rejected parts that are produced in-house by the molder in initial molding processes. These materials are crushed to smaller size and recycled with virgin materials. Regrind excludes materials that are chemically reconstituted or repolymerized, or regrind bought in bulk and used by another company. It only applies to post-industrial (pre-consumer) waste from the same manufacturer.
[www.ul.com]

Regrind Contamination
It has been my experience that the biggest problem with regrind is not excessive heat history but contamination, both foreign plastic and foreign materials. How many of us have seen production stop due to a plugged hot tip. This has forced many to use nozzle filters to prevent downtime and the significant cost of cleaning out the hot runner system. A nozzle filter creates a pressure drop and further reduces process robustness. This is the reason why you can save money by running only virgin in hot runner tools and use the regrind for cold runner tools. Not many have this luxury but when possible it is a winning strategy.

Further if there is contamination how do you purge the resin system? The only sure way is to sell all of your regrind and start over. There is no way to purge the resin stream of contamination with 20% regrind.
[articles.ides.com]

Compounding
Compounding consists of preparing plastic formulations by mixing or/and blending polymers and additives in a molten state.
[en.wikipedia.org]

Fillers
Lower the consumption of more expensive binder material or to better some properties of the mixtured material.
Modified and reinforced plastics provide increased mechanical performance and allow plastics to be
used to solve the unique and challenging material requirements.

carbon black
glass fibers
carbon fibers
mica
talc
gypsum
calcium carbonate (limestone)
kaolin (clay)
alumina trihydrate
[en.wikipedia.org]
[www.plasticmaterials.net]

Degraded Polymer in the Regrind
Most consider that using up to 25% regrind does not significantly compromise virgin resin properties. Unfortunately this statement can get you in trouble. For example: Resins such as nylon, polycarbonate, poly(butadieneterephthalate) (PBT), poly(ethyleneterephthalate) (PET), etc, if not dried properly before initial processing will undergo a chemical reaction, called hydrolysis, in the barrel of the molding machine which causes significant lowering of the polymer chain length. This is not visible to the naked eye; parts look good but have lower physical or chemical properties. Often the problem is not found until the parts are in service, which can be a costly issue. Blending regrind of this quality into virgin at 25% levels may significantly alter subsequent part performance and function. Further each processing history may influence the virgins additive levels and if fiber filled the length of the fibers. Processing grinds up the fibers to shorter lengths. Then there is the problem with processing the virgin at higher than recommended temperatures, a sure way to accelerate polymer degradation. These are only a sample of the potential problems of using regrind and all of them can narrow the processing window.

Temperature or heat history is commonly believed to be the biggest issue in polymer degradation. However a study done by Sue Janicki et al. Antec 1992 pgs 1201-1204; "The Material Cascade: An Alternative Form of Regrind Utilization" (pdf) provides data showing excellent retention of physical properties through five passes through an injection molding machine. The study included High Impact Polystyrene (HIPS), Ignition Resistant HIPS and Polycarbonate (PC). This indicates that if treated properly in processing that many resins can hold their physical properties for a short number of regrind passes.
[articles.ides.com]