3D printing materials
Which materials does a 3D printer use, and which ones should I choose? Approaching this world, this is one of the first questions coming on mind. Different 3d printing materials change with the kind of 3d printing technology. Once again we are focusing on FFF – Fused Filament Fabrication (or FDM – Fused Deposition Modeling), that means printing objects through the melting of 3d printer filament made by polymers, because this is the easiest technique. Filament, usually with a diameter between 3 and 1.75 mm, is heated by a resistance and, passing through a nozzle, it lays down layer after layer taking the shape of the object that we are printing. So let’s go into the substance of the main materials used for this technology, analyzing differences and applications.
ABS
ABS and PLA are the most widespread 3D printing materials. They are two thermoplastic polymers: it means that they become flexible and manipulable at high temperatures and go back to solid cooling down (reversible process). The choice between these two materials is an eternal dilemma. There are hundreds of supporters fighting for each cause, but it doesn’t mean that it’s not possible to draw up precise features that distinguish the two polymers. The truth is that for a good choice you should just try both ABS and PLA, using them depending on what you want to do.
ABS filaments (Acrylonitrile, Styrene, Acrylate) can be used to create light and rigid objetcs, like, for example, Lego bricks, parts of car body, hydraulic tubes, musical instruments like flutes or clarinets. ABS derives from petroleum. It is soluble in acetone (so you can sand it with a brush, or weld different pieces with few drops of fluid).
Strengths: lightness, strength, durability, resistance to high temperatures (up to 100 degrees), easy to use and to reuse, good flexibility.
Weaknesses: bad smell and toxic fumes, need a heated plate, easily warping.
Discover more about 3D printing of PP in our Materials Guide.
ASA
Structurally similar to ABS, filament ASA (Acrylonitrile, Styrene, Acrylate) resists to UV rays and water: so, getting old, it doesn’t get that typical yellowish colour (for this reason it is frequently used for outdoor furniture and objetcs).
PLA
PLA (polylactic acid) is made by a polymer derived from vegetable products processing, including corn. Naturally transparent, it can be painted, made matte or shiny. For this reason, PLA filaments are suitable for artistic and aesthetic uses, small domestic objetcs or for educational purpose in the schools. Its solvent is caustic soda.
Strenghts: ecological (vegetal origin, compostable in industrial structures), it can be extruded at lower temperatures (doesn’t need heated plate), low warping, transparent look.
Weaknesses: less strong, more rigid, it begins to deteriorate at 60 degrees.
Discover more about 3D printing of PLA in our Materials Guide.
PET-G
PET-G is part of the PET family (Polyethylene terephthalate), it’s a very common plastic for industrial use especially in the packaging business(bottles).
In 3D printing, PET-G filaments are very diffused for being quite easy to print with better mechanical properties than PLA.
Strenghts: good mechanical proprieties, discrete performances at high temperatures, relatively low-cost, also transparent.
Weaknesses: frequent defects on parts (stringing, small holes), limited mechanical performances.
Discover more about 3D printing of PET-G in our Materials Guide.
Polypropylene (PP)
Polypropylene (PP) is one of the most commonly used plastics for industrial production, with an outstanding range of different applications. It’s appreciated for the ability of working without breaking and for its resistance to chemicals.
The applications are many: containers, labels, tape but also a lot in the chemical and biomedical field.
Strenghts: tenacity of the parts, chemical resistance, smooth finishing, good for contacts with liquid, food, skin.
Weaknesses: extreme shrinking during the print, hard to manage complex shapes.
Discover more about 3D printing of PP in our Materials Guide.
Nylon
The main benefit of Nylon is its resistance: it is much more stronger than previous polymers. Flexible and durable, it melts at high temperatures, often more than 250 degrees. Part of the synthetic polyamide family, it was originally used in textile production. Its main lack is the tendence to warping, like ABS (also with Nylon you need heated plate). Moreover, you must dry it very well before printing, because it easily absorbs water, even from the air: better dry it in the oven for few hours.
TPU and TPE
Thermoplastic elastomers are polymers that put together the characteristics of rubbers with the processability of thermoplastic polymers. Two common thermoplastic elastomers are TPU and TPE.
These materials can be easily pigmented and they are long-lasting thanks to their great elasticity and resistance to abrasion.
The applications are wide from objects of everyday use to specific products for the biomedical field.
Strenghts: elasticity, softness, many colors, long-lasting.
Weaknesses: some complexities during the print, relatively low speed.
Discover more about 3D printing of TPU-TPE in our Materials Guide.
Polycarbonate (PC)
Polycarbonate is very resistent to warmth. It is often used as electrically insulating, in medical application and in some mechanical parts of mobile phones. It easily warps, so you always need a heated plate. It is one of the most tough and resistant material. It melts above 260-270 degrees.
Strenghts: very resistant parts, translucid, good performance at high temperature, rigid parts.
Weaknesses: high processing temperatures, sensible to moisture (hygroscopic), relatively expansive.
Discover more about 3D printing of PC in our Materials Guide.
Composed materials
Composed materials for 3d printing are products made by the combination of two or more materials from different origins, of which at least one made by fibre. Assembling different materials allows to improve thermal and mechanical performance and also rigidity. One of the most common composed material is polyamide with glass fibre, that needs, however, 50% of fibre at least. Another composed material, that guarantees high performances with lower percentages, is the one made on carbon fibres.
Strenghts: very stiff parts, nice matt finishing, good permormance at high temperature, easy to print.
Weaknesses: extremely hygroscopic, the fibers inside make it abrasive (also for the nozzle).
Discover more about 3D printing of PA Carbon in our Materials Guide.