New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive

I have to assume this is Hytrel based on the availability at the time and suspicious overlap between Shore 82 value cited in their whitepapers and duponts site. [www2.dupont.com]. There aren't many alternatives.

Imo, printing shore A 82 isn't impressive. Its probably even easier to push that "soft pla." Its hard to say with any certainty, and while not all materials are created equal there seem to be dozens of alternatives. My only reason for switch would be cost. Kraton G is easily going to cost users $12/lb + just for raw pellets, let alone processing, packaging, and forming. Little room for people to appreciate a markup there.

It was actually 72 Shore A durometer for the 'STPE-2' elastomer. Hytrel was my first guess as well, but since all of the variants I saw at a first glance were beige in color (and Jan's samples appear to be clear/colorless), it could be a compound from a different maker.

Have you looked overseas for sourcing the Kraton? Digging through Alibaba and the like turn up resin prices that are far less than purchasing through a domestic distributor.

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[haveblue.org]

Update for all those who are following:

It is unlikely that a Shore A 50 filament or below will extrude under 5 mm diameter. Its just too squishy. If it is fiber filled or loaded with some kind of additive, it may be more likely to work. However, filament around Shore A 80 has been proven many times over now and could work, I'm just suspect as to its utility.

At present, I've shifted my work away from designing new filaments towards an even loftier goal. Currently, the field has begun to fill up with nice new filaments. I will try to summarize them when I have time here. These include

Taulman Nylon (Self proclaimed best quality for reprap and heats around 245)
High shore value existing 3-4 mm TPE's, and Proprietary unidentified polymer E20 for Dimension systems.
"Soft PLA"
Wood filled filament.
Static shielding (so called "conductive") ABS
ABS, PLA, PP, PE, PVA, PC, PVC

I do find that polymers such as metal-filled, fiber-filled, truly conductive, and magnetic are still missing. However, I think there is a bigger win here for reprap. The holy grail of the carriage mounted granule extruder, which I've finally come close to solving. This new extruder will allow the following materials (at its best, optimized):

Rubber of ANY consistency or shore value
Light cure polymer
Wax
Sand
Metal or plastic powder
Nylon
Delrin
And all the prior existing filaments. IMO, this is a MUCH bigger win and much more worth the time. Reprap WILL move to auger extruders, and already is, as I've been told on the DL from the engineers at more than one reprap and one non-reprap printer companies.

Still missing LEP filament :-)

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-Tom

LEP? Light emitting?

Yessir! Not saying it's even possible, just throwing it out there.

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-Tom

I've thought of this one, and it is totally possible. in fact, I've seen at least two articles where its been done. However, you can make something glow in the dark or luminese is not the same as high quality controlled AMOLED.

Simba Wrote:
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> I do find that polymers such as metal-filled,
> fiber-filled, truly conductive, and magnetic are
> still missing. However, I think there is a bigger
> win here for reprap. The holy grail of the
> carriage mounted granule extruder, which I've
> finally come close to solving. This new extruder
> will allow the following materials (at its best,
> optimized):

YES! Reinforced (glass-, carbon-, and/or mineral-filled) polymers are most definitely needed! Even Stratasys doesn't have anything like this. Glass-filled polycarbonate/ABS, yummy!

And I fully agree - the holy grail really is a granule based extruder. In case anyone doesn't see the advantages:
* Cheaper to operate (you can purchase raw resin for much less than the cost of just extruding it into filament)
* Ability to custom formulate resins (want a 20%/80% PC/ABS blend? 1 scoop PC, 4 scoops ABS)
* Better retention of material properties (remember, extrusion of resin into filament means that we're already printing with non-virgin material)
* No patent encumbrances that I'm aware of
* Ability to use extremely soft resins that can't be reliably fed as filament
* ...and probably a few other bonuses that I'm missing...

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[haveblue.org]

Heres one, How about explosive filiments. Seriously. If an object could be crafted with these matierials through them the Mil might find them usefull for OpSec as radio housings and the like could self detonate if properly promted. Safty. There are many explosives that are very stable. Shouldn't be a problem.

... better mould the stuff than printing - excessive heat may change the chemistry, so not really usefull

The moulding form can be fabbed directly or made from a printed primer ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Not to mention that voids within the deposited material could have unintended effects on the burn rate and shockwave propagation.

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[haveblue.org]

Just to follow up on this thread, while I'm certain augers are better moving forwards, many will still appreciate new materials.

Why hasn't anyone done class acetal (homopolymer similar to Delrin but less temperature sensitive).?
Why hasn't anyone done a soft material?

At present we are tying to push for making filaments of delrin and shore A 90 rubber. For Delrin, the material will be recommended for printing outside or in a garage because the potential long term health hazards of formaldehyde offgassing are not something we want to risk liability for (allbeit, ABS does the same thing, people are used to it)

I finally managed to coerce get raw PLA resin from two suppliers. I will be using this as the workhorse for my upcoming Auger-printer (Tentatively named the Industries3D Augr).

GH401 is a chinese equivalent (or knock off) and Cereplast in USA which is also competitor to Natureworks. Both are natural, virgin, creamy-translucent-white pellets. Based on this I have to assume "white" PLA is actually filled with TALC, Zn Oxide, or Ti Oxide, and come to think of it it has the graininess of white filler. If this filler is slippery (like Talc) it would explain the extreme difference in properties between white and black PLA. Sorry if this is re-discovery for anyone here, but its a learning process for me : ).

I have NO idea why PLA resin can not be purchased raw online, amazon, ebay, injection molding suppliers, etc. It must be something that can't keep up with demand is my guess. Anyway, if anyone is interested, a group buy could get PLA down to $8/lb for raw pellets in 250lb increments (shipped). Isn't that amazing - at 2.2kg, it is almost similar in price to rolled PLA filament! (http://makemendel.com/pla/natural-pla-filament). PLA from china is half price but takes 60 days to receive in port, and who knows about quality. Perhaps this means all PLA filament is from china...

Edited 2 time(s). Last edit at 12/11/2012 10:41PM by Simba.

New update - I'm getting replies to my inquiry for Kevlar-filled nylon 6/6. I'm SURE some people here would be interested : D?

Kevlar doesnt melt right? so every print has a continuous thread of kevlar... Yep I'd try it! :-)

You'd have to avoid overheating the Kevlar during processing, however, because Kevlar will sort of decompose at high temps.

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-Tom

its pretty much similar to fiber or glass reinforced I think. I may be wrong, it just sounded cool and worth playing with.

Here is some stuff you've likely seen before, but never in such a nice and presentable form!

Granule extruders:
[reprapdelft.files.wordpress.com]

I have to add, our filament quality is looking better right now than they had in 2010, but so is everyone else who made a lyman-type filament extruder


My review of the few attempts to make a mini granule extruder reveal the following inhibiting features:

1. The extruders do not have enough force and speed
2. The extruders get clogged at the top with pellets that clump and stick together, stopping the motion of new pellets from going through
3. The extruders work once but can not be started again on heat -up due to clogging within the top entrance of the nozzle (different clog than above).
4. In addition, they are too BIG to make a compact reprap, but this isn't a deal breaker like the above.
5. In addition, weight was never mentioned as a limiting feature

...Fascinating.

Edited 3 time(s). Last edit at 12/12/2012 11:35PM by Simba.

If the window is still open, I would like to get my hands on some of each of the new print materials, including the heavy-weight, the rubbery, and the conductive materials. I have a solidoodle2 machine, 1.75mm filemant feed, without the heated build platform.

Kevlar fill sounds neat, but I don't think it would be terribly useful as a 3D printing filament. The benefit of aramid fibers in composite construction is that if the epoxy matrix fails, the Kevlar will still hold together (whereas fiberglass or carbon fiber will break along with the matrix). However, aramids may be less abrasive than other fibers, which would make them well suited for reinforcement in printers that don't have replaceable nozzles (such as a few Stratasys models).

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[haveblue.org]

We produce two types of elastic filament that is very strong and elastic. If you print thicker walls your object becomes less flexible. Great for timing belts etc and very strong. http://3dprinterfilaments.com/rubber_%20like_filaments

I am interested in 1.75mm electrically conductive filament. What type of material and what is the resistance?

Thanks,

Scott

Yes, Kevlar is very interesting. However my need is for conductive filament to print a circuit board.

Bless all these nice filaments, even I love when new filaments comes out, kind of feel like christmas evreyday

The last reply in this thread was over a year old.

@KeithCI
If weight is all you need, then you can simply add a couple internal holes and fill them with some of those irksome spare pennies. They're about 2.5 times denser than ABS!