Resin Vs. Plastic Filament

[TeddyYan]

Could someone please explain what the difference is between Plastic filament like most 3D printers use, and the Resin that Peachy Printer is using? Is Resin plastic? Is it similar? I've heard it is more expensive then plastic. Why?

Also, how does Resin work? How does it liquify and harden?

Ted

[Josh@MakerJuice]

How these resins work is really beyond the scope of a forum discussion. The basics are a photo-catalyst interacts with electron beam or UV radiation, generating free radicals which cause cross-linking in the monomer/polymer chains of the resins. There are many differences between the finished resins and thermoplastics depending on the type of resin and plastic.

They are considered to be plastics when cured.

Resin is still a little more expensive than the thermoplastics due to the materials involved and the distribution/availability. We're obviously working to reduce that differential. As it stands, MakerJuice resins are pretty close to the cost of decent ABS/PLA.

[kanningphish]

Resins are a liquid that are cured by a laser, or some sort of light source. These print with very high resolution, and you seem hardly any lines (if any) in your prints like you do with FDM (filament based) printers. After owning a Replicator 2 for some time now, I don't know why anyone would choose a filament printer over a resin printer. Does anyone know what the benefits of a filament printer are over a resin based printer?

[Feign]

I believe Josh answered this pretty handily. Out of curiosity, I did some digging trying to find recipes for photopolymers... The results were a bit beyond my ability. But what it seems to be is that to you have a base of a resin and catalyst, with an extra chemical that stops the curing process before it can begin. This extra chemical is what breaks down when exposed to UV, allowing the curing to happen selectively.

The end result is that the cured resin is effectively identical to a regular two-part resin that is its base. Working with two-part casting resins should give you an idea of the properties of the photopolymers of the same type.

Of course, all of this is to the best of my very, very amateur knowledge.

[mike_biddell]

The more interesting question is how the physical properties stack up..... e.g. melting point, tensile etc.

[Slatye]

Does anyone know what the benefits of a filament printer are over a resin based printer?

Cost, both in materials and in buying the printer.

The Peachy has completely killed the up-front cost argument; resin printers have gone from five times the price of a cheap FDM printer to half the price of a cheap FDM printer. Can't argue with that.

Resins are still more expensive than filament, but they're getting cheaper (when the Form 1 was announced the resin was something like $200/L, now it's under $50/L) and the printer capabilities reduce consumption anyway (greatly reduced need for support structures, better reliability so there's less waste, etc). Realistically, the cost is now low enough that any normal object is going to be "a dollar or so", and nobody really cares that on an FDM printer it might only be 20c (plus six hours of trying to persuade the FDM printer to work reliably).


As Mike has said, physical properties might be a bigger factor. FDM printers have to use thermoplastics, primarily ABS and PLA. Both are rigid (necessary as they have to support themselves during the print and get pulled/pushed through the printer) and have a low melting point (necessary as they have to be extruded). The Peachy's resin should have a much higher melting point for a start, which probably doesn't really matter to anyone (it's still not high enough to replace metals). The much more interesting aspect is that because the structure is largely supported by water, you can use flexible resin. Makerjuice have been producing some nice rubbery ones, which will be perfect for kids' toys, phone cases, vibration dampers, etc.