3D Printer Filaments Explained

How to Cull the Correct Filament

Afterward you option a 3D printer, the outset determination y'all'll have to make is what type of filament you desire to use. There are several dozen varieties—fifty-fifty setting aside the numerous colors they come up in. Wading through them surfaces a string of chemical-sounding names: polylactic acid, polyvinyl alcohol, carbon fiber, and the tongue-twisty thermoplastic elastomers, for case. They get by a boundless variety of acronyms, ABS, PLA, HIPS, CPE, PET, PETT, TPE, PVA, and PCTPE among them. Only don't be dismayed by this alphabet soup. Only a few types are in common utilize, and manufacturers tend to eschew overly geeky monikers in favor of more descriptive names alluding to an essential quality of the filament such as flexibility (NinjaTek'southward Ninjaflex and Polymaker'due south Polyflex, for case) and strength (Makerbot and XYZprinting both market place filaments called Tough PLA, and Ultimaker will soon innovate a tough PLA of its own).

Filament Nuts

Filaments used in 3D printing are thermoplastics, which are plastics (aka polymers) that melt rather than burn down when heated, can be shaped and molded, and solidify when cooled. The filament is fed into a heating bedroom in the printer'southward extruder assembly, where it is heated to its melting signal and then extruded (squirted) through a metal nozzle as the extruder assembly moves, tracing a path programmed into a 3D object file to create, layer by layer, the printed object. Although almost 3D printers have a single extruder, there are some dual-extruder models that tin print an object in different colors or with different filament types.

The process of printing with plastic filament is called either fused filament fabrication (FFF) or fused deposition modeling (FDM). They're the same thing; the FDM acronym is trademarked by 3D printing pioneer Stratasys Corp., so other manufacturers created their own names to draw their printers' technology; FFF is the i that caught on. Fifty-fifty today, except in some manufacturers' brochures, yous'll see the names used interchangeably.

Filament is sold in spools by weight ranging from 0.5 kilogram to 2 kilograms. The filament comes in 2 thicknesses, 1.75 millimeters and iii millimeters. (The latter is in reality a piddling thinner, about ii.85 millimeters.) The vast majority of filament is of the 1.75-millimeter blazon; Ultimaker and LulzBot are among the few manufacturers whose printers use the thicker size. Weight is almost always listed in metric units.

At present, let'south have a await at a few of the more popular and of import filament types.

The Dynamic Duo: ABS and PLA

Past far, the almost common filament types are acrylonitrile butadiene styrene (ABS) and polylactic acrid (PLA). Most bones 3D printers are designed to exclusively employ these filaments. Office of their appeal is that they're relatively inexpensive, costing equally little every bit $20 per kilogram.

Don't be put off past ABS's unwieldy chemic proper noun; it'due south the same plastic used in Legos. Objects printed from ABS are tough, durable, and nontoxic. It has a relatively high melting point, with a impress temperature ranging from 210 degrees to 250 degrees Celsius. The bottom corners of objects being printed with ABS take a trend to curl up a flake, peculiarly if you are using a not-heated print bed. During printing, ABS can emit an acrid, unpleasant smell, so it's best used with a closed-frame printer in a well-ventilated room.

PLA has a relatively low melting bespeak, with usable temperatures between 180 degrees and 230 degrees Celsius. It is plant-based and biodegradable. It's harder than ABS, prints without warping, and is generally easy to work with, although in rare cases it tin cause extruder jams. PLA is often used as the base of operations material for more exotic, composite materials, which nosotros will hash out in a bit.

Nylon

Nylon is an incredibly versatile synthetic material, developed in the 1930s, that has found use in everything from toothbrushes to parachutes to tires to stockings, and at present 3D printer filament. At its center it'due south a polymer, or plastic (or, more precisely, a family of plastics). Information technology is strong and durable, nevertheless flexible, and among the lowest-priced 3D printing filaments. It melts at a higher temperature (nearly 240 degrees Celsius) than well-nigh filaments. Non all 3D printers are built to handle that heat—some unremarkably used substances in the extruder emit fumes at that temperature. Like with ABS, objects printed with nylon have a tendency to warp, which can be mitigated past using a heated print bed.

Flexible Filament

TPEs (or thermoplastic elastomers) are thermoplastics with high elasticity (though still far short of, say, safe bands); objects printed with them are relatively flexible. One common TPE type is thermoplastic polyurethane (TPU), of which NinjaFlex is a popular example.

Soluble Filaments: HIPS and PVA

Ane of the more than tricky acronyms, HIPS, stands for loftier-bear on polystyrene. HIPS is moderately priced, lightweight, and tin be sanded, glued, and colored with acrylic paints. Information technology is similar to ABS, except that HIPS is soluble in Limonene, a citrus-based solvent, making it a good pick—when printing with a second material (such as ABS or PLA) with a dual-extruder printer—every bit a back up textile that could be dissolved subsequently printing. It likewise prints well on its own, and is the filament recommended past LulzBot for its LulzBot Mini 3D Printer, which earned our Editors' Choice. MakerBot Dissolvable Filament is also comprised of HIPS.

Another soluble filament is PVA (polyvinyl booze), which conveniently dissolves in water. PVA is odorless, nontoxic, and biodegradable. It has a low melting bespeak, and can jam an extruder nozzle when overheated. It is oft used equally a support material in dual-extruder printers; I tested the Ultimaker three by printing a test object—a box inside a box—using PLA for the boxes themselves and PVA as the back up. After the object was printed, I immersed it in warm water, and the PLA gradually dissolved, leaving the pair of nested boxes.

Composite Filaments

Blended filaments have a base of PLA or other thermoplastic into which particles, powders, or flakes of other materials have been mixed. Some are wood blends, others include sandstone or limestone, and still others take various kinds of metals, including fe, aluminum, brass, statuary, and copper. These filaments take on some of the backdrop of the materials they have been mixed with. Another popular blended is carbon fiber; objects printed from it have some of the strength of the fiber. A downside to these composite filaments is that they cost considerably more than non-composites.

Beyond Plastic Filament: Resin-Based Printing

With today'south proliferation of FFF printers, it's easy to overlook the fact that there are models on the marketplace based on other technologies that don't use filament. Chief among them is stereolithography (aka SLA), the first 3D press engineering science to have been developed, and which is capable of very detailed, high-resolution prints. Price tags for SLA printers for commercial use can run well into 5 (and even into six) figures, but we accept seen some lower-priced models, suitable for hobbyists and artisans.

In SLA printing, an ultraviolet light amplification by stimulated emission of radiation traces the shape of the object to be printed, layer by layer, on a UV-sensitive resin (aka photopolymer, or photopolymer resin) housed in a tray or vat, and the resin exposed to the light amplification by stimulated emission of radiation hardens to form the printed object. The resins come in 500-milliliter and one-liter bottles, with prices from printer manufacturers starting at near $100 per liter. Some manufacturers take formulated resins for strength, flexibility, rigidity, and other qualities, and such resins tend to sell at a premium. Resins have suffered from a express color palette, and take tended to exist confined to black, gray, white, and clear, though some brighter-colored and metallic resins have get available of late.

DLP is a form of stereolithography that uses a projector in place of the laser as a light source, using visible low-cal instead of ultraviolet. The projector, which employs Texas Instruments' DLP (Digital Light Processing) technology, projects a serial of images into a vat of photopolymer resin like to the resins used in SLA printing to build the object, layer by layer.

Now that y'all know everything you demand to nigh the most popular filaments, yous'll desire to read our 3D printer buying guide, which includes reviews of the best models we've recently tested. You lot can also check out what an early adopter had to say almost his fourth dimension learning to print in 3D.