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

Posted by Simba 
New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 25, 2012 12:59PM
Hi!

We have been developing novel polymers for the Reprap machines (we have a solid doodle, prusa MG2, and Makerbot). The polymers have the following goal:

1) Make parts heavier / more rigid by weighing them down with metal particles. They are still fully insulators, but they do conduct heat better.
2) Make rubbery materials - these are great for potentially making flexible / translucent materials, or items that might need padding (headphones) or better cling to surfaces (tires)
3) Make waxy materials - this may be useful for lower cost and loss-wax casting of metals
4) Conductive polymers - self-explanitory
5) Semi conductive polymers - basically, to allow you to conduct microamps to send signals to switches OR to print varying resistance values (from about 1000-1e8 ohms). There may be value in creating large scale junctions (say one is P type and one is N type) but we don't know enough to understand this yet.

We are thinking about scaling them up, if anyone else would care for these materials? Would anyone like to be a beta tester for the items (1-4) ?

Thanks!


Measure once, Cut twice, Print 3 times.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 25, 2012 01:28PM
i would love to test them. looking to design and build a wide variety of items to sell so the more materials to choose from the better. weight concerns me a bit because i also want to produce a few lamps also so a heavier base would always go down well.

do you have a website that i can have a look at?

Edited 1 time(s). Last edit at 09/25/2012 01:31PM by keithCl.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 25, 2012 01:43PM
I would love to try new print materials. Let me know when/where I could get them.

-Nick
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 25, 2012 02:15PM
I'd definitely be up for being a beta tester!


------------------------------------------
garyhodgson.com/reprap | reprap.development-tracker.info | thingtracker.net
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 25, 2012 03:05PM
I would be interested in the first one. More rigid would be good for what I need.

What are the heated bed and extruder temperatures for it?

David
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 03:55AM
For those interested in some rubbery material, GRRF has some soft PLA, soft enough so you can make knots on the filament - just remember to undo the knots before pushing that into your extruder spinning smiley sticking its tongue out


Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 04:50AM
I'd be interested in testing any of those.
Would #1 be prone to nozzle clogging?
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 09:13AM
Happy to test anything. What kinds of temps do they run at?
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 10:06AM
These are still in development, but generally they run around 185 C because they are embedded in PLA or ABS.
The rubber may need to run up to 230 C
The waxes run around 85 C.

It seems like weighted-polymers are of great interest so we are starting out focus there.

As nicely summarized here: [www.ptonline.com]
  • Weighted polymers add a great look and/or feel of quality to a product.
  • They add impact resistance and improve the modulus of the product.
  • They may improve the quality of prints because the weight may help bond layers together better
  • They may improve heat flow by modifying the thermal conductivity of the materal, especially for devices that built up heat and need dissipation.

A good comparison example is for dental fillings. These fillings by themselves would be about as hard as acrylic, without the fillers. However, the ceramic fillers make the infill material so strong that it becomes resistance to damage (at the cost of increasing brittleness).
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 10:06AM
Me too, always happy to test out new materials.


[richrap.blogspot.com]
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 10:47AM
If you're still looking for testers, please do get in touch with me. We've got people who are interested in both testing and publishing the results.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 01:46PM
Wish I could test some, but I probably won't build my printer until May.sad smiley
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 26, 2012 07:57PM
I would be happy to test some filament as well! A rubbery material would be very nice for printing out more complex one piece molds.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 27, 2012 02:04AM
Rubbery and low temperature waxy filaments get my vote, for mold making and casting, especially after seeing this [3dtopo.com]
Very happy to be a beta tester for you!I
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 27, 2012 04:24PM
droftarts Wrote:
-------------------------------------------------------
> Rubbery and low temperature waxy filaments get my
> vote, for mold making and casting, especially
> after seeing this [3dtopo.com]
> Very happy to be a beta tester for you!I


For those requesting rubbery materials, it might help to define the kind of rubber, because it's probably a good start but not a one-size-fits-all solution.

The rubber we used is between hard a soft. Its fairly similar to those bouncy balls you can buy from the vending machine at any grocery store. That would be assuming you could deposit it as a solid mass that well annealed together. In reality its a slight bit more squishy, like a rubber eraser (but stronger as a material). I'm not sure how useful this is as a material for your applications so help me imagine your proposed setup - A mold like a silicone/candy making mold that you cast in would make perfect sense. An intricate piece with say bridging and small features makes less sense because it wouldn't hold up under its own weight. But that's why I'm offering up free demos to figure out what works.

Very VERY cool link @Droftarts. I didn't think there was a chance PLA could be smelted out of place to give way to such fine feature resolution.

What do you think about the idea of pre-embedding the gypsum into the PLA? Since it absorbs a small amount of water, the surface of the PLA would totally resist breakdown by the molten metal, and might provide a conduit for molten metal flow - This should work well for general structures, but when you have nooks and crannies you'd probably want to use the standard method as shown in the video to make sure there are no air pockets. The only nice thing is being able to remake the mold a little easier.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 27, 2012 10:44PM
I normally use rubbers with a durometer of between 25A and 40A when moldmaking (Or between a rubber band material and a door seal material), so something with the hardness of an eraser would be pretty good. I'm interested in doing exactly what you said; printing out molds to then cast directly into. Right now the workflow is to print the piece, mold it, and then cast it. Being able to print flexible molds directly would cut out a lot of time and cost.

You could even put it into a dual extruder system, and print the mold and the part it casts all at once, which would ensure accuracy in the final cast parts.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 28, 2012 05:11PM
Silicone caulk is easy to extrude with a paste extruder, and it is an acceptable mold material. I have cast polyurethane and low-melting-temperature-alloy parts in a 3D printed mold made from DAP 08641 Silicone Sealant.

This Fab at Home page has quite a bit of information on 3D printed molds.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 28, 2012 08:52PM
MattMoses - I've seen people try and have tried myself to make molds with silicon caulk, and the molds created are far inferior quality (in terms of air bubbles and mold strength) to ones created with a molding rubber. My concern with printing caulk would be molds breakage (The bouncy ball/sphere that is on that page has some breakage in the final pictures, and that is after only one pull). Having a mold break after only a few uses is not economical, obviously.

I don't have any idea if the filament Simba is offering would do any better, but that's what testing is for!

EDIT: After reading through that picture set again, I see now that the mold is actually frosting and the pull is silicon! It's quite impressive that they got the frosting to break so little. I still feel as though a filament would do better than a paste, if for no other reason than the limited amount of material one can put into a syringe!

Edited 1 time(s). Last edit at 09/28/2012 09:07PM by PomeroyB.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 28, 2012 09:07PM
Hey,

Today we extruded some 3 mm diameter clear rubber....based on these runs I would say the rubber is somewhere between Shore A Duro 70 and 85. It is also unique stretchy (like a rubber band) with nearly 400% stretch, and yet it is quite a tough materal. For example, to drill some rubber cast in a 3mm ID aluminum tube damaged the aluminum significantly (with a <3mm drill bit).

However, rubber has the unique advantage in 3D printing where if you use low % fill, you can mimick a Durometer far weaker than itself. In other words, printing porous Shore A 80 rubber at 10% fill might represent the properties of a Shore A 35 polymer. Hopefully, we can back that up with results soon.

Also Today we talked about print linear low density polyethylene, which melts around 120 C and is a very soft plastic.
Feel free to throw around ideas for alternate materials!
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 28, 2012 09:12PM
Very cool, Simba! Are you running it through an extruder with a hobbed bolt? Does the 400% stretch affect the way it is pulled through?
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 29, 2012 05:06PM
Great stuff Simba! Got a few thoughts I want to toss out.

1 - How about trying a ferrous filler?

2 - Maybe a lubricious filler to make something similar to a flouropolymer? I think the chemical emissions during printing might make this a non-starter... not really sure. Could be nice for parts like bearings/bushings etc if it could be pulled off. Also this type of material probably wouldn't absorb much moisture since the space in between the materials molecules is filled with oily filler molecules that keep the water molecules out.

3 - How about a filler that makes PLA parts easier to sand/finish and paint?
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 30, 2012 04:36AM
Wouldn't any stone (mineral) filler aid in finishing?
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
September 30, 2012 06:00AM
This is a very interesting development. I have been considering developing an extruder which adds filler to ABS filament in the extruder head. Ready made plastic filament just takes this one stage further, but does fix the plasic / filler ratio which means you won't be able to print parts with varying properties very easily.

I think adding a non melting filler to ABS would potentially eliminate the shrinking / warping issues meaning that large cheap prints might be possible. I was thinking of carbon powder, wood flour etc. and using the plastic filament to drag the powder through the nozzle.

One further problem is that if you use stone, glass etc. the brass nozzle would be wear very quickly.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 01, 2012 07:08PM
Can we get some pictures please?
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 01, 2012 07:26PM
ACETAL please! (delrin trade name). It sticks to itself lile mad, better than abs, and melts lower, self lubricating etc...
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 01, 2012 07:41PM
Quote

ACETAL please! (delrin trade name). It sticks to itself lile mad, better than abs, and melts lower, self lubricating etc...

Just did some digging into MSDS, toxicity, etc. Acetal may be a safer alternative to Nylon for a high strength self-lubricating material.

Only catch is it will outgas formaldehyde if over-heated. Melt point is listed as around 175C.
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 02, 2012 05:00PM
I love Delrin!!!
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 02, 2012 08:19PM
I'm assembling an Ultimaker and adding a heated bed to make parts for my commercial product. I'd be very interested in testing materials that are heavy or rubbery, and very impact resistant.

Thanks!
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 02, 2012 10:40PM
Count me in as a beta tester! What do you need printed? smiling smiley


FabberForge - Printing Happiness

[www.fabberforge.com]
Re: New Filaments - Heavy Weight, Rubbery, Conductive, Semi-conductive
October 03, 2012 12:20AM
Awesome!

Throwing my printer in for testing if you need one.

Can't wait for these to hit the stores!
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