Polycarbonate printing

I'd try slowing everything down to 25mm/s and increasing both your width and thickness. Maybe .8mm wide and +.3mm tall, if that takes care of it then ease up to more standard W&Ts. If not I'd say see what you can do to get the ambient air warmer and/or your extruder cooler.

Decent in this case is perhaps 3 cubic inches.

I haven't printed with it in a while, I need to. It's a pretty fun plastic, even if you have to play around with it more than ABS or PLA.

Let us know if fatter traces help the cracking.

Ok, Will give that a shot.

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www.Fablicator.com

I have been printing with Orbi-Tech's 3mm polycarbonate filament and got pretty good results with the same settings I used for ABS. 50mm/s, 0.2-0.25 mm layer height, 2.0 W/T, 0.35 Arcol V4 extruder. I had to go to 300C temperature to get strong parts. Seems to warp somewhat more than ABS, but for example the common large extruder gear still printed fine.

It also has some properties which are better than ABS's:

* Filament won't strip, E motor will just skip steps even at max current
* More fluid, but still solidifies easier. Small things which ended up being a blob of jello when printing with ABS printed fine with PC. Except the bridge... I couldn't get the bridging to work at all.
* Overhangs printed really well

hello yall 1

im interested to know what mods to the hotend? nichrome wire type to get to up to 330c ?

also, [www.protoparadigm.com] = pure PC or PC/ABS ?

are there any toxic fumes to be wary of for PC printing?

im trying to find materials that wud be above 80c crystalization

Edited 1 time(s). Last edit at 08/19/2012 09:35PM by redreprap.

redreprap Wrote:
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> also,
> [www.protoparadigm.com]
> -polycarbonate/ = pure PC or PC/ABS ?

Pure PC. I have some of it to play with, though I haven't extruded any of it yet.

Not sure about fumes, though the MSDS only has a warning for fumes above the decomposition temperature, which is hotter than we would ever want to extrude it at.

You just need a hot-end with heat break made of metal (usually a thin tube of stainless steel) instead of PEEK or PTFE, since neither of these plastics can take the temperature needed for extruding PC. The usual ceramic heater resistors and thermistors work fine even at PC temperatures. (At least mine do)

The smell when extruding is not bad, PC smells better than even high quality ABS. But it's still probably not really good for you...

this is certainly very interesting to me as i am looking for some print feeds with high crystal temps ...

can anyone supply info about the gas emitted during a print? i hear it will require a good extractor, its poisonous? yes? no?

Richrap,

I don't know off hand what the exact volatiles are and couldn't find them quickly enough to avoid getting frustrated with google, so...

This quote from the AMtrust group plastic mfg safety guide says it all as far as I'm concerned. I bolded the rightfully alarming stuff.

"Plastics processing generates a variety of toxic dusts, vapors and fumes from the molding, forming and extruding of plastics. Resins, various chemical additives and modifiers present a significant chemical exposure hazard for production workers. Some commonly used hazardous chemicals are ketones, polyvinyl acetate, styrene, mineral spirits and acetones. Studies show that plastics processing workers have elevated risks of liver cancer and brain tumors because some plastics processing chemicals contain carcinogens. Other associated ailments are heart and kidney disease, occupational dermatitis and various long-term respiratory problems.

Inherently hazardous to workers, welding activities present health hazards from noise, electric shock, fires and explosions, and exposure to welding smoke (gases and fumes). Welding smoke can lead to acute or chronic respiratory diseases, carcinoma of the lungs, eye irritation, skin irritation, skin cancer, reduced sperm count and motility, and infertility.

Flammable solvents for degreasing, parts cleaning and chemical treatment operations are noted for long-term adverse health effects. The negative effects include elevated risks of liver and kidney disease, respiratory illness, dermatitis, allergic reactions and cancer."

I know that some naive kids will scoff and call me a kook and do their best to discount it as hersay or boooring, but having worked in an environment that was thick with the fumes of Stoddard fluid for ~7 years, I've learned that it's better to be cautious. (I won't be getting cancer from it afaik, but it did give me some serious headaches and made me pretty queasy after a while, and even after I left the job, I could still "taste" it in my food for months and smell it in my clothes, no matter how many times I washed them. One shirt and a pair of jeans that got thoroughly soaked due to a spray nozzle that got away from me during testing went to an early grave in the garbage they were so bad.)

When in doubt, ventilate. Why learn that you *should have been, 20 years later when your kid is getting ready to graduate from highschool, or you've finally retired from the daily grind with things left to do? And inline vent fan, some dryer vent flex tub, and a bit of creativity pumps it outside, away from your lungs, your partner's lungs, your pet's lungs, and your children's lungs. Especially your children's lungs.

Anyone who's done a good deal of soldering without a fume extractor understands. A little bit almost smells nice, or at least just smells "interesting". After a while though and it's cloying, and after a while longer it's just plain nasty. And by "while" I don't mean a couple hours, I mean a few months or years.

ymmv and your choices are ultimately yours.

PS...I almost forgot to ask the question that led me here in the first place. What heated-bed temperature are you using for PC extrusion? I'm building up my first system and want it as flexible to start as possible. I know nylon and PC run at higher extrusion temps so I assume the heated bed temp is higher than for ABS as well (power supply rating, etc.)

Edited 2 time(s). Last edit at 09/01/2012 08:27PM by xiando.

Ok, found something a bit more definitive but still not a full list, (and only for one representative product).

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Parsed from: [www.perspex.co.uk]

"Unlikely to be hazardous by inhalation. High concentrations of vapour from hot operations may be harmful,
cause irritation of the respiratory tract."

Article goes on to say the decomposition components (decomposition temp is ~400C) are "Hydrocarbons, Phenol, Carbon Monoxide"

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So then phenol, considering that CO is pretty well known, and "hydrocarbons" is too vague to chase

Phenol:
From [www.osha.gov]

"Effects on Humans: The effects of phenol exposure in humans are similar to those produced in animals: systemic absorption causes central nervous system impairment and liver and kidney damage; local effects include irritation of the eyes, skin and mucous membranes[Hathaway et al. 1991]. Because of its low volatility, phenol does not pose a serious inhalation hazard in the occupational setting; the skin is a primary route of entry [Hathaway et al. 1991; Parmeggiani 1983]."

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I would think that would be the normal case, ie, it's pretty safe as long as we don't over-heat it, but seeing that these rigs are experimental, accidents happen, heaters go full up, etc. so it's better safe than sorry.

Even if the hot-end jams and overheats, it will only cook a small amount of plastic. The decomposition products would have to be seriously toxic for that to be a hazardous situation. Of the commonly used plastics, only the ones containing halogens (PVC and PTFE for example) are worth worrying in this regard.

That said, at least my hot-ends always have some slowly decomposing plastic stuck around the nozzle and a long term exposure to the fumes can't be a good thing no matter what the plastic type is. So ventilating to outside air or perhaps using an active carbon filter would be a good idea in any case.

Personally, I consider my own outgassing and decomposition products to be more hazardous.

I have printed a couple small extruder gears using PC on my prusa, I put a large flat on them such as the sli3er brim feature but I use Kisslicer. The best print sofar is the Stratos Glider [www.thingiverse.com]
her is a link to the first one I printed before he added a version with a "beard" to keep the front of the plane down.
[www.thingiverse.com]
The plane is very durable compared to the PLA one I printed, and a lot of fun.

My settings were extruder 270-280 and bed temps of 110-115.

Impressive and encouraging! How well does she fly?

it flys well, with several rubberbands it flys up then loops almost back to me.
Forgot to mention: nozzle is .35mm extrusion width .38 and layer height of .20

I tried to print a cat toy and it was to week at 275, i think that the temp needs to more like 300. The planes print are only a couple mm tall so i think as the taller objects are cooler because they dont get the benefit of the heat from the bed.

Hey richrap can you go into details of your extruder and how you were able to achieve high enough temps to extrude PC?

Thanks
Dan

Daniel Stein Wrote:
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> Hey richrap can you go into details of your
> extruder and how you were able to achieve high
> enough temps to extrude PC?

There's nothing secret in it, you can go and just buy an extruder which works at 270-300 degrees. Arcol.hu makes one, and there are other makers as well. I guess you could make one yourself too, just make sure that everything in the hot side is metal or ceramic. (So no PEEK, no PTFE)

I have made about a dozen prints in GizmoDorks black PC with great success with my MakerGear M2 and E3D. I have even successfully printed a 160mm tall part with 99% infill that was 0.5 lbs of PC with no warping. I did make an enclosure though - I don't expect it will work well without one. I can't get big ABS parts to work well without one either though.

A few layers of glue stick on bare glass (which is what I use for any filament). I use the purple kind.

Bed at 110-120C, but I started a print a 90 and that worked also, so I can't say that it must be 110 or more. I am getting more an more casual about not waiting for it to heat up and no problems so far.

Print speeds no higher than 60 mm/sec for best quality. I did 80 mm/sec and it was just detectably worse on inner curves, though still ok for a "fast" mode.

290C worked even with 300 micron layers 0.48mm wide at 80 mm/sec, so I see no reason to go higher temp.

100 micron layers had much stronger bonding than 300 micron layers.

Flat parts don't need a brim. Tall parts need a brim.

No strings at all.

PC won my pull test, with PolyMax coming in second. eSun PETG is an awesome material:

[forum.makergear.com]

This was my first part. Flat and easy, but the tall 0.5 lb part came out perfect also.



Edited 1 time(s). Last edit at 04/08/2015 01:00AM by rsilvers.

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[www.matter-replicator.com]

MakerGear M2 with E3D, 1/10 scale, 290C, 50 micron layers, GizmoDorks Polycarbonate, 60 mm/sec.

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[www.matter-replicator.com]