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What material does a 3d printer print with
Guide to 3D Printing Materials: Types, Applications, and Properties
3D printing empowers you to prototype and manufacture parts for a wide range of applications quickly and cost-effectively. But choosing the right 3D printing process is just one side of the coin. Ultimately, it'll be largely up to the materials to enable you to create parts with the desired mechanical properties, functional characteristics, or looks.
This comprehensive guide to 3D printing materials showcases the most popular plastic and metal 3D printing materials available, compares their properties, applications, and describes a framework that you can use to choose the right one for your project.
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Need some help figuring out which 3D printing material you should choose? Our new interactive material wizard helps you make the right material decisions based on your application and the properties you care the most about from our growing library of resins.
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There are dozens of plastic materials available for 3D printing, each with its unique qualities that make it best suited to specific use cases. To simplify the process of finding the material best suited for a given part or product, let’s first look at the main types of plastics and the different 3D printing processes.
There are the two main types of plastics:
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Thermoplastics are the most commonly used type of plastic. The main feature that sets them apart from thermosets is their ability to go through numerous melt and solidification cycles. Thermoplastics can be heated and formed into the desired shape. The process is reversible, as no chemical bonding takes place, which makes recycling or melting and reusing thermoplastics feasible. A common analogy for thermoplastics is butter, which can be melted, re-solidify, and melted again. With each melting cycle, the properties change slightly.
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Thermosetting plastics (also referred to as thermosets) remain in a permanent solid state after curing. Polymers in thermosetting materials cross-link during a curing process that is induced by heat, light, or suitable radiation. Thermosetting plastics decompose when heated rather than melting, and will not reform upon cooling. Recycling thermosets or returning the material back into its base ingredients is not possible. A thermosetting material is like cake batter, once baked into a cake, it cannot be melted back into batter again.
The three most established plastic 3D printing processes today are the following:
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Fused deposition modeling (FDM) 3D printers melt and extrude thermoplastic filaments, which a printer nozzle deposits layer by layer in the build area.
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Stereolithography (SLA) 3D printers use a laser to cure thermosetting liquid resins into hardened plastic in a process called photopolymerization.
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Selective laser sintering (SLS) 3D printers use a high-powered laser to fuse small particles of thermoplastic powder.
Video Guide
Having trouble finding the best 3D printing technology for your needs? In this video guide, we compare FDM, SLA, and SLS technologies across popular buying considerations.
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Fused deposition modeling (FDM), also known as fused filament fabrication (FFF), is the most widely used form of 3D printing at the consumer level, fueled by the emergence of hobbyist 3D printers.
This technique is well-suited for basic proof-of-concept models, as well as quick and low-cost prototyping of simple parts, such as parts that might typically be machined.
Consumer level FDM has the lowest resolution and accuracy when compared to other plastic 3D printing processes and is not the best option for printing complex designs or parts with intricate features.
Higher-quality finishes may be obtained through chemical and mechanical polishing processes. Industrial FDM 3D printers use soluble supports to mitigate some of these issues and offer a wider range of engineering thermoplastics or even composites, but they also come at a steep price.
As the melted filament forms each layer, sometimes voids can remain between layers when they don’t adhere fully. This results in anisotropic parts, which is important to consider when you are designing parts meant to bear load or resist pulling.
FDM 3D printing materials are available in a variety of color options. Various experimental plastic filament blends also exist to create parts with wood- or metal-like surfaces.
The most common FDM 3D printing materials are ABS, PLA, and their various blends. More advanced FDM printers can also print with other specialized materials that offer properties like higher heat resistance, impact resistance, chemical resistance, and rigidity.
| Material | Features | Applications |
|---|---|---|
| ABS (acrylonitrile butadiene styrene) | Tough and durable Heat and impact resistant Requires a heated bed to print Requires ventilation | Functional prototypes |
| PLA (polylactic acid) | The easiest FDM materials to print Rigid, strong, but brittle Less resistant to heat and chemicals Biodegradable Odorless | Concept models Looks-like prototypes |
| PETG (polyethylene terephthalate glycol) | Compatible with lower printing temperatures for faster production Humidity and chemical resistant High transparency Can be food safe | Waterproof applications Snap-fit components |
| Nylon | Strong, durable, and lightweight Tough and partially flexible Heat and impact resistant Very complex to print on FDM | Functional prototypes Wear resistant parts |
| TPU (thermoplastic polyurethane) | Flexible and stretchable Impact resistant Excellent vibration dampening | Flexible prototypes |
| PVA (polyvinyl alcohol) | Soluble support material Dissolves in water | Support material |
| HIPS (high impact polystyrene) | Soluble support material most commonly used with ABS Dissolves in chemical limonene | Support material |
| Composites (carbon fiber, kevlar, fiberglass) | Rigid, strong, or extremely tough Compatibility limited to some expensive industrial FDM 3D printers | Functional prototypes Jigs, fixtures, and tooling |
Stereolithography was the world’s first 3D printing technology, invented in the 1980s, and is still one of the most popular technologies for professionals.
SLA parts have the highest resolution and accuracy, the clearest details, and the smoothest surface finish of all plastic 3D printing technologies. Resin 3D printing is a great option for highly detailed prototypes requiring tight tolerances and smooth surfaces, such as molds, patterns, and functional parts. SLA parts can also be highly polished and/or painted after printing, resulting in client-ready parts with high-detailed finishes.
Parts printed using SLA 3D printing are generally isotropic—their strength is more or less consistent regardless of orientation because chemical bonds happen between each layer. This results in parts with predictable mechanical performance critical for applications like jigs and fixtures, end-use parts, and functional prototyping.
SLA offers the widest range of material options for plastic 3D printing.
SLA 3D printing is highly versatile, offering resin formulations with a wide range of optical, mechanical, and thermal properties to match those of standard, engineering, and industrial thermoplastics.
| Formlabs Materials | Features | Applications |
|---|---|---|
| Standard Resins | High resolution Smooth, matte surface finish | Concept models Looks-like prototypes |
| Clear Resin | The only truly clear material for plastic 3D printing Polishes to near optical transparency | Parts requiring optical transparency Millifluidics |
| Draft Resin | One of the fastest materials for 3D printing 4x faster than standard resins, up to 10x faster than FDM | Initial Prototypes Rapid Iterations |
| Tough and Durable Resins | Strong, robust, functional, and dynamic materials Can handle compression, stretching, bending, and impacts without breaking Various materials with properties similar to ABS or PE | Housings and enclosures Jigs and fixtures Connectors Wear-and-tear prototypes |
| Rigid Resins | Highly filled, strong and stiff materials that resist bending Thermally and chemically resistant Dimensionally stable under load | Jigs, fixtures, and tooling Turbines and fan blades Fluid and airflow components Electrical casings and automotive housings |
| Polyurethane Resins | Excellent long-term durability UV, temperature, and humidity stable Flame retardancy, sterilizability, and chemical and abrasion resistance | High performance automotive, aerospace, and machinery components Robust and rugged end-use parts Tough, longer-lasting functional prototypes |
| High Temp Resin | High temperature resistance High precision | Hot air, gas, and fluid flow Heat resistant mounts, housings, and fixtures Molds and inserts |
| Flexible and Elastic Resins | Flexibility of rubber, TPU, or silicone Can withstand bending, flexing, and compression Holds up to repeated cycles without tearing | Consumer goods prototyping Compliant features for robotics Medical devices and anatomical models Special effects props and models |
| Medical and dental resins | A wide range of biocompatible resins for producing medical and dental appliances | Dental and medical appliances, including surgical guides, dentures, and prosthetics |
| Jewelry resins | Materials for investment casting and vulcanized rubber molding Easy to cast, with intricate details and strong shape retention | Try-on pieces Masters for reusable molds Custom jewelry |
| ESD Resin | ESD-safe material to improve electronics manufacturing workflows | Tooling & fixturing for electronics manufacturing Anti-static prototypes and end-use components Custom trays for component handling and storage |
| Ceramic Resin | Stone-like finish Can be fired to create a fully ceramic piece | Engineering research Art and design pieces |
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Selective laser sintering (SLS) 3D printing is trusted by engineers and manufacturers across different industries for its ability to produce strong, functional parts. Low cost per part, high productivity, and established materials make the technology ideal for a range of applications from rapid prototyping to small-batch, bridge, or custom manufacturing.
As the unfused powder supports the part during printing, there’s no need for dedicated support structures. This makes SLS ideal for complex geometries, including interior features, undercuts, thin walls, and negative features.
Just like SLA, SLS parts are also generally more isotropic than FDM parts. SLS parts have a slightly rough surface finish due to the powder particles, but almost no visible layer lines.
SLS 3D printing materials are ideal for a range of functional applications, from engineering consumer products to manufacturing and healthcare.
The material selection for SLS is limited compared to FDM and SLA, but the available materials have excellent mechanical characteristics, with strength resembling injection-molded parts. The most common material for selective laser sintering is nylon, a popular engineering thermoplastic with excellent mechanical properties. Nylon is lightweight, strong, and flexible, as well as stable against impact, chemicals, heat, UV light, water, and dirt.
| Material | Description | Applications |
|---|---|---|
| Nylon 12 | Strong, stiff, sturdy, and durable Impact-resistant and can endure repeated wear and tear Resistant to UV, light, heat, moisture, solvents, temperature, and water | Functional prototyping End-use parts Medical devices |
| Nylon 11 | Similar properties to Nylon 12, but with a higher elasticity, elongation at break, and impact resistance, but lower stiffness | Functional prototyping End-use parts Medical devices |
| TPU | Flexible, elastic, and rubbery Resilient to deformation High UV stability Great shock absorption | Functional prototyping Flexible, rubber-like end-use parts Medical devices |
| Nylon composites | Nylon materials reinforced with glass, aluminum, or carbon fiber for added strength and rigidity | Functional prototyping Structural end-use parts |
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Different 3D printing materials and processes have their own strengths and weaknesses that define their suitability for different applications. The following table provides a high level summary of some key characteristics and considerations.
| FDM | SLA | SLS | |
|---|---|---|---|
| Pros | Low-cost consumer machines and materials available | Great value High accuracy Smooth surface finish Range of functional materials | Strong functional parts Design freedom No need for support structures |
| Cons | Low accuracy Low details Limited design compatibility High cost industrial machines if accuracy and high performance materials are needed | Sensitive to long exposure to UV light | More expensive hardware Limited material options |
| Applications | Low-cost rapid prototyping Basic proof-of-concept models Select end-use parts with high-end industrial machines and materials | Functional prototyping Patterns, molds, and tooling Dental applications Jewelry prototyping and casting Models and props | Functional prototyping Short-run, bridge, or custom manufacturing |
| Materials | Standard thermoplastics, such as ABS, PLA, and their various blends on consumer level machines. High performance composites on high cost industrial machines | Varieties of resin (thermosetting plastics). Standard, engineering (ABS-like, PP-like, flexible, heat-resistant), castable, dental, and medical (biocompatible). | Engineering thermoplastics. Nylon 11, Nylon 12, and their composites, thermoplastic elastomers such as TPU. |
Beyond plastics, there are multiple 3D printing processes available for metal 3D printing.
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Metal FDM
Metal FDM printers work similarly to traditional FDM printers, but use extrude metal rods held together by polymer binders. The finished “green” parts are then sintered in a furnace to remove the binder.
SLM and DMLS printers work similarly to SLS printers, but instead of fusing polymer powders, they fuse metal powder particles together layer by layer using a laser. SLM and DMLS 3D printers can create strong, accurate, and complex metal products, making this process ideal for aerospace, automotive, and medical applications.
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Titanium is lightweight and has excellent mechanical characteristics. It is strong, hard and highly resistant to heat, oxidation, and acid.
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Stainless steel has high strength, high ductility, and is resistant to corrosion.
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Aluminum is a lightweight, durable, strong, and has good thermal properties.
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Tool steel is a hard, scratch-resistant material that you can use to print end-use tools and other high-strength parts..
- Nickel alloys have high tensile, creep and rupture strength and are heat and corrosion resistant.
Compared to plastic 3D printing technologies, metal 3D printing is substantially more costly and complex, limiting its accessibility to most businesses.
Alternatively, SLA 3D printing is well-suited for casting workflows that produce metal parts at a lower cost, with greater design freedom, and in less time than traditional methods.
Another alternative is electroplating SLA parts, which involves coating a plastic material in a layer of metal via electrolysis. This combines some of the best qualities of metal—strength, electrical conductivity, and resistance to corrosion and abrasion—with the specific properties of the primary (usually plastic) material.
Plastic 3D printing is well-suited to create patterns that can be cast to produce metal parts.
With all these materials and 3D printing options available, how can you make the right selection?
Here’s our three-step framework to choose the right 3D printing material for your application.
Plastics used for 3D printing have different chemical, optical, mechanical, and thermal characteristics that determine how the 3D printed parts will perform. As the intended use approaches real-world usage, performance requirements increase accordingly.
| Requirement | Description | Recommendation |
|---|---|---|
| Low performance | For form and fit prototyping, conceptual modeling, and research and development, printed parts only need to meet low technical performance requirements. Example: A form prototype of a soup ladle for ergonomic testing. No functional performance requirements needed besides surface finish. | FDM: PLA SLA: Standard Resins, Clear Resin (transparent part), Draft Resin (fast printing) |
| Moderate performance | For validation or pre-production uses, printed parts must behave as closely to final production parts as possible for functional testing but do not have strict lifetime requirements. Example: A housing for electronic components to protect against sudden impact. Performance requirements include ability to absorb impact, housing needs to snap together and hold its shape. | FDM: ABS SLA: Engineering Resins SLS: Nylon 11, Nylon 12, TPU |
| High performance | For end-use parts, final 3D printed production parts must stand up to significant wear for a specific time period, whether that’s one day, one week, or several years. Example: Shoe outsoles. | FDM: Composites SLA: Engineering, Medical, Dental, or Jewelry Resins SLS: Nylon 11, Nylon 12, TPU, nylon composites |
Performance requirements include strict lifetime testing with cyclic loading and unloading, color fastness over periods of years, amongst others like tear resistance.Once you’ve identified the performance requirements for your product, the next step is translating them into material requirements—the properties of a material that will satisfy those performance needs. You’ll typically find these metrics on a material’s data sheet.
| Requirement | Description | Recommendation |
|---|---|---|
| Tensile strength | Resistance of a material to breaking under tension. High tensile strength is important for structural, load bearing, mechanical, or statical parts. | FDM: PLA SLA: Clear Resin, Rigid Resins SLS: Nylon 12, nylon composites |
| Flexural modulus | Resistance of a material to bending under load. Good indicator for either the stiffness (high modulus) or the flexibility (low modulus) of a material. | FDM: PLA (high), ABS (medium) SLA: Rigid Resins (high), Tough and Durable Resins (medium), Flexible and Elastic Resins (low) SLS: nylon composites (high), Nylon 12 (medium) |
| Elongation | Resistance of a material to breaking when stretched. Helps you compare flexible materials based on how much they can stretch. Also indicates if a material will deform first, or break suddenly. | FDM: ABS (medium), TPU (high) SLA: Tough and Durable Resins (medium), Polyurethane Resins (medium), Flexible and Elastic Resins (high) SLS: Nylon 12 (medium), Nylon 11 (medium), TPU (high) |
| Impact strength | Ability of a material to absorb shock and impact energy without breaking. Indicates toughness and durability, helps you figure out how easily a material will break when dropped on the ground or crashed into another object. | FDM: ABS, Nylon SLA: Tough 2000 Resin, Tough 1500 Resin, Grey Pro Resin, Durable Resin, Polyurethane Resins SLS: Nylon 12, Nylon 11, nylon composites |
| Heat deflection temperature | Temperature at which a sample deforms under a specified load. Indicates if a material is suitable for high temperature applications. | SLA: High Temp Resin, Rigid Resins SLS: Nylon 12, Nylon 11, nylon composites |
| Hardness (durometer) | Resistance of a material to surface deformation. Helps you identify the right “softness” for soft plastics, like rubber and elastomers for certain applications. | FDM: TPU SLA: Flexible Resin, Elastic Resin SLS: TPU |
| Tear strength | Resistance of a material to growth of cuts under tension. Important to assess the durability and the resistance to tearing of soft plastics and flexible materials, such as rubber. | FDM: TPU SLA: Flexible Resin, Elastic Resin, Durable Resin SLS: Nylon 11, TPU |
| Creep | Creep is the tendency of a material to deform permanently under the influence of constant stress: tensile, compressive, shear, or flexural. Low creep indicates longevity for hard plastics and is crucial for structural parts. | FDM: ABS SLA: Polyurethane Resins, Rigid Resins SLS: Nylon 12, Nylon 11, nylon composites |
| Compression set | Permanent deformation after material has been compressed. Important for soft plastics and elastic applications, tells you if a material will return to its original shape after the load is removed. | FDM: TPU SLA: Flexible Resin, Elastic Resin SLS: TPU |
For even more details on material properties, read our guide to about the most common mechanical and thermal properties.
Once you translate performance requirements to material requirements, you’ll most likely end up with a single material or a smaller group of materials that could be suitable for your application.
If there are multiple materials that fulfil your basic requirements, you can then look at a wider range of desired characteristics and consider the pros, cons, and trade-offs of the given materials and processes to make the final choice.
Try our interactive material wizard to find materials based on your application and the properties you care the most about from our growing library of materials. Do you have specific questions about 3D printing materials? Contact our experts.
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Ultimate Materials Guide - Tips for 3D Printing with PLA
Overview
Polylactic Acid, commonly known as PLA, is one of the most popular materials used in desktop 3D printing. It is the default filament of choice for most extrusion-based 3D printers because it can be printed at a low temperature and does not require a heated bed. PLA is a great first material to use as you are learning about 3D printing because it is easy to print, very inexpensive, and creates parts that can be used for a wide variety of applications. It is also one of the most environmentally friendly filaments on the market today. Derived from crops such as corn and sugarcane, PLA is renewable and most importantly biodegradable.
As a bonus, this also allows the plastic to give off a sweet aroma during printing.
- Low Cost
- Stiff and good strength
- Good dimensional accuracy
- Good shelf life
- Low heat resistance
- Can ooze and may need cooling fans
- Filament can get brittle and break
- Not suitable for outdoors (sunlight exposure)
Hardware Requirements
Before 3D printing with PLA make sure your 3D Printer meets the hardware requirements listed below to ensure the best print quality.
Bed
Temperature: 45-60 °C
Heated Bed Optional
Enclosure not required
Build Surface
Painter’s tape
PEI
Glass plate
Glue stick
Extruder
Temperature: 190-220 °C
No special hot-end required
Cooling
Part Cooling Fan Required
Fan Speed: 100%
Best Practices
These tips will help you reduce the chances of common 3D printing issues associated with PLA such as stringing, oozing, or under-extrusion.
Fine Tune the Retractions to Prevent Oozing
One of the most common problems with PLA is oozing. Since the filament flows relatively easily when compared to the other materials, it has a tendency to continue flowing during travel movements at the end of a segment. This creates strings or hairs on your part, and dialing in your retraction settings is the best way to combat this behavior! Different brands of PLA and different printers may need slightly different retraction settings, so you may need to experiment to find the best value for your printer. Simplify3D added a very useful feature in Version 4.0 that can help with this, by allowing you to quickly try dozens of different settings, and then look at the final part to determine which one worked the best on your specific setup. For example, you could setup two vertical pillars which are printed side-by-side to evaluate stringing when moving back-and-forth between each pillar. Then go to Tools > Variable Settings Wizard and choose how you want to adjust your settings during the print.
For example, you could try a different retraction distance for each 20mm section of the print and then pick the value that works best in the end. For more tips on how to reduce stringing and oozing, be sure to check out our Print Quality Guide which contains an entire section dedicated to this issue: How to Reduce Stringing and Oozing.
Optimize Your Cooling Settings
Cooling is one of the most important aspects of printing with PLA. Having a dedicated part cooling fan makes a huge difference in the quality of the printed parts. The freshly extruded plastic needs to cool down below the glass transition temperature as quickly as possible. This will prevent the plastic from stringing and producing other artifacts. We recommend setting the fan to 100% throughout the print, except for the first 1-2 layers where you want to form a strong bond with the print bed. Simplify3D also includes a useful option on the Cooling tab of your process settings that can automatically reduce the print speed for small parts, ensuring that the layers have sufficient time to cool.
This can greatly improve the print quality by allowing the layer to solidify before printing the next layer on top of it. This setting can be found on the Speeds tab of your process settings.
Choose the Correct Extruder Temperature
This is a great tip for any filament, but is especially useful for PLA which often contains different combinations of additives depending on the manufacturer. These different additives can lead to variations in printing temperature between 190-230 degrees Celsius. If you are not printing at the right temperature this can lead to several print quality issues including oozing, stringing, and under-extrusion. PLA can also be combined with different fills like metal, wood, and fiber that give it different characteristics than a standard homogeneous PLA. These may require different settings or even different hardware. Be sure to check with the manufacturer of your filament to verify the optimal temperature to use for your specific filament. If you have trouble with stringing, try reducing this temperature by 5-10 degrees, which will help prevent the excess oozing.
If you’re struggling with under-extrusion, try increasing the temperature by 10 degrees so that the material flows more easily through the nozzle.
Pro-Tips
- Using a fan that cools the 3D printed part from all directions is highly recommended. Many popular 3D printers have community-designed attachments that can be printed and retrofitted onto your machine to improve the cooling airflow.
- Increasing the number of perimeter outlines for your PLA prints will create a strong bond between each layer, creating stronger parts that are less prone to breaking.
Get Started with PLA
Now that you are ready to start printing with PLA, here’s a bit more information to help you get started. Start thinking of project ideas by reviewing our common applications, try out one of the provided sample projects, or find a new filament to try from our list of popular material brands.
Common Applications
- Test and calibration items
- Dimensionally accurate assemblies
- Decorative Parts
- Cosplay Props
Sample Projects
- LA Spring Motor, Rolling Chassis
- G – Clamp
- Storm Trooper Helmet
Popular Brands
- Polymaker PLA, PolyMax, PolyPlus
- ColorFabb PLA/PHA
- Hatchbox PLA
- eSun PLA
- Filamentum PLA
What material does the 3D printer print with? Plastic for 3d printer.
Layer-by-layer printing of three-dimensional models is made from a variety of materials, be it plastic, concrete or metal, and even hydrogel, chocolate and living cells.
For 3D printing, the use of ABS plastic is most optimal. Acrylonitrile butadiene styrene (official name ABC plastic ) is valued for the absence of foreign smell, toxicity, in addition, it is impact resistant, flexible and elastic. The material begins to melt from 240 to 248 degrees Celsius. Plastic goes on sale in a powdered state, or in the form of bobbins with plastic threads wound around them. Despite the fact that plastic does not tolerate direct sunlight, models made from it are famous for their durability. Plastic for a 3D printer can be bought in our online store.
Unlike ABC plastic, which models are opaque, acrylic is used to create transparent objects. But acrylic is more capricious in the process of use: the melting point of acrylic is reached later, which means that it will take more time and energy to heat up, and at the same time it quickly cools and hardens.
The very process of manufacturing the product is laborious, since heated acrylic contains a lot of air bubbles that can distort the finished product.
Concrete applied for 3D printing , improved, and has a formula that differs from the formula of conventional cement by 5%. The “printing” of a residential building with an area of 230 m2 on a 3D printer will take no more than 20 hours, during which it carefully “lays out” building blocks and structures from concrete.
The use of hydrogel for 3D printing was successfully tested by scientists from the University of Illinois, who used a 3D printer to print miniature (5-10 mm) biorobots. Living cells isolated from the tissue of the heart muscle were placed on them, which, spreading through the hydrogel, set the biorobot in motion. The speed of such a biorobot is 236 µm/s. As planned by scientists, in the future, with the help of such biorobots, tumors and toxins in the body will be detected and neutralized, and they will also be used to deliver medications to diseased human organs.
There are 3D printers that use ordinary office paper as a material. Pre-cut layers of paper are applied one on top of the other and attached with glue. Paper models are cheap enough that they are accessible to users, but at the same time, paper models are not durable and not aesthetically pleasing. Models created in this way are ideal for prototyping in computer projects.
Gypsum used for 3D printing is a fragile, short-lived material, but at the same time it has a low cost. Therefore, models made of plaster are mainly suitable for presentations, perfectly conveying the shape, structure and size of the original product. The resistance of gypsum to heat treatment makes it possible to use it in the foundry as samples for casting.
Fans of natural wood and products made from it will also enjoy 3D printing, as there is a specially designed “wood” fiber that contains wood and a polymer, and its properties are similar to polyactide (PLA). Outwardly looking like natural wooden models with the smell of fresh wood, they are quite strong and durable.
Currently, the material can only be used in the RepRap self-replicating printers.
3D printing with ice is perhaps the most exotic way of making small figures today. The temperature at which the figures are printed is quite low and is -22 degrees Celsius, and the printing material is water and methyl alcohol heated to 20 degrees Celsius.
The pleasant soft sheen and high strength of the metal are far ahead in quality of any plastic used in 3D printing, therefore light and precious metal powders are successfully used in this area. Copper, aluminum and its alloys, gold and silver in powder form are used for printing, adding fiberglass and ceramic inclusions to them.
Nylon printed parts are similar in many ways to ABS plastic parts, but are softer and more practical. Nylon manufacturing technology is more capricious, in particular, it has a longer curing period, the printing temperature reaches 320 degrees Celsius, and it is more toxic.
The 3D printers of the near future will print shaped chocolate molds, which should be in great demand in restaurants and pastry shops.
It is also impossible not to mention polycaprolactone, the most popular consumable for 3D printing. This material is so valued for its excellent physical properties and the possibility of being used in various printing technologies.
Of the plastic materials for printing, it is also worth highlighting polycarbonate (hard plastic), polylactide material obtained from biomass, sugar beet or corn silage, polypropylene, polyphenylsulfone, which came from the aviation industry, and an unsurpassed leader in the field of 3D printing, used in any of its areas - polyethylene low pressure.
Among other things, there are also printers that carry out 3D printing with mixtures of clay, lime powder, food, cells from living organic matter. And what exotic materials will be printed 3D printers in the future, one can only guess.
3D printing for dummies or "what is a 3D printer?"
- 1 3D printing term
- 2 3D printing methods
- 2.
1 Extrusion printing - 2.2 Melting, sintering or gluing
- 2.3 Stereolithography
- 2.4 Lamination
- 3 Fused Deposition Printing (FDM)
- 3.1 Consumables
- 3.2 Extruder
- 3.3 Working platform
- 3.4 Positioners
- 3.5 Control
- 3.6 Varieties of FDM printers
- 4 Laser Stereolithography (SLA)
- 4.1 Lasers and projectors
- 4.2 Cuvette and resin
- 4.3 Types of stereolithographic printers
The term 3D printing
The term 3D printing has several synonyms, one of which quite briefly and accurately characterizes the essence of the process - "additive manufacturing", that is, production by adding material. The term was not coined by chance, because this is the main difference between multiple 3D printing technologies and the usual methods of industrial production, which in turn received the name "subtractive technologies", that is, "subtractive".
If during milling, grinding, cutting and other similar procedures, excess material is removed from the workpiece, then in the case of additive manufacturing, material is gradually added until a solid model is obtained.
Soon 3D printing will even be tested on the International Space Station
Strictly speaking, many traditional methods could be classified as "additive" in the broad sense of the word - for example, casting or riveting. However, it should be borne in mind that in these cases, either the consumption of materials is required for the manufacture of specific tools used in the production of specific parts (as in the case of casting), or the whole process is reduced to joining ready-made parts (welding, riveting, etc.). In order for the technology to be classified as “3D printing”, the final product must be built from raw materials, not blanks, and the formation of objects must be arbitrary - that is, without the use of forms. The latter means that additive manufacturing requires a software component.
Roughly speaking, additive manufacturing requires computer control so that the shape of final products can be determined by building digital models. It was this factor that delayed the widespread adoption of 3D printing until the moment when numerical control and 3D design became widely available and highly productive.
3D printing methods
3D printing technologies are numerous, and there are even more names for them due to patent restrictions. However, you can try to divide technologies into main areas:
Extrusion printing
This includes methods such as deposition fusion (FDM) and multi-jet printing (MJM). This method is based on the extrusion (extrusion) of consumables with the sequential formation of the finished product. As a rule, consumables consist of thermoplastics or composite materials based on them.
Melting, sintering or bonding
This approach is based on bonding powdered material together.
Formation is done in different ways. The simplest is gluing, as is the case with 3D inkjet printing (3DP). Such printers deposit thin layers of powder onto the build platform, which are then selectively bonded with a binder. Powders can be made up of virtually any material that can be ground to a powder—plastic, wood, metal.
This model of James Bond's Aston Martin was successfully printed on Voxeljet's SLS printer and just as successfully blown up during the filming of Skyfall instead of the expensive original
sintering (SLS and DMLS) and smelting (SLM), which allow you to create all-metal parts. As with 3D inkjet printing, these devices apply thin layers of powder, but the material is not glued together, but sintered or melted using a laser. Laser sintering (SLS) is used to work with both plastic and metal powders, although metal pellets usually have a more fusible shell, and after printing they are additionally sintered in special ovens. DMLS is a variant of SLS installations with more powerful lasers that allow sintering metal powders directly without additives.
SLM printers provide not just sintering of particles, but their complete melting, which allows you to create monolithic models that do not suffer from the relative fragility caused by the porosity of the structure. As a rule, printers for working with metal powders are equipped with vacuum working chambers, or they replace air with inert gases. Such a complication of the design is caused by the need to work with metals and alloys subject to oxidation - for example, with titanium.
Stereolithography
How an SLA printer works
Stereolithography printers use special liquid materials called "photopolymer resins". The term "photopolymerization" refers to the ability of a material to harden when exposed to light. As a rule, such materials react to ultraviolet irradiation.
Resin is poured into a special container with a movable platform, which is installed in a position near the surface of the liquid. The layer of resin covering the platform corresponds to one layer of the digital model.
Then a thin layer of resin is processed by a laser beam, hardening at the points of contact. At the end of illumination, the platform together with the finished layer is immersed to the thickness of the next layer, and illumination is performed again.
Lamination
Lamination 3D printers (LOM)
Some 3D printers build models using sheet materials - paper, foil, plastic film.
Layers of material are glued on top of each other and cut along the contours of the digital model using a laser or a blade.
These machines are well suited for prototyping and can use very cheap consumables, including regular office paper. However, the complexity and noise of these printers, coupled with the limitations of the models they produce, limit their popularity.
Fused deposition modeling (FDM) and laser stereolithography (SLA) have become the most popular 3D printing methods used in the home and office.
Let's take a closer look at these technologies.
Fused Deposition Printing (FDM)
FDM is perhaps the simplest and most affordable 3D construction method, which makes it very popular.
High demand for FDM printers is driving device and consumable prices down rapidly, along with technology advances towards ease of use and improved reliability.
Consumables
ABS filament spool and finished model
FDM printers are designed to print with thermoplastics, which are usually supplied as thin filaments wound on spools. The range of "clean" plastics is very wide. One of the most popular materials is polylactide or "PLA plastic". This material is made from corn or sugar cane, which makes it non-toxic and environmentally friendly, but makes it relatively short-lived. ABS plastic, on the other hand, is very durable and wear-resistant, although it is susceptible to direct sunlight and can release small amounts of harmful fumes when heated.
Many plastic items that we use on a daily basis are made from this material: housings for household appliances, plumbing fixtures, plastic cards, toys, etc.
In addition to PLA and ABS, printing is possible with nylon, polycarbonate, polyethylene and many other thermoplastics that are widely used in modern industry. More exotic materials are also possible, such as polyvinyl alcohol, known as "PVA plastic". This material dissolves in water, which makes it very useful for printing complex geometric patterns. But more on that below.
Model made from Laywoo-D3. Changing the extrusion temperature allows you to achieve different shades and simulate annual rings
It is not necessary to print with homogeneous plastics. It is also possible to use composite materials imitating wood, metals, stone. Such materials use all the same thermoplastics, but with impurities of non-plastic materials.
So, Laywoo-D3 consists partly of natural wood dust, which allows you to print "wooden" products, including furniture.
The material called BronzeFill is filled with real bronze, and models made from it can be ground and polished, achieving a high similarity to products made from pure bronze.
One has only to remember that thermoplastics serve as a binding element in composite materials - they determine the thresholds of strength, thermal stability and other physical and chemical properties of finished models.
Extruder
Extruder - FDM print head. Strictly speaking, this is not entirely true, because the head consists of several parts, of which only the feed mechanism is directly "extruder". However, by tradition, the term "extruder" is commonly used as a synonym for the entire print assembly.
FDM extruder general design
The extruder is designed for melting and applying thermoplastic thread. The first component is the thread feed mechanism, which consists of rollers and gears driven by an electric motor.
The mechanism feeds the thread into a special heated metal tube with a small diameter nozzle, called a "hot end" or simply a "nozzle". The same mechanism is used to remove the thread if a change of material is needed.
The hot end is used to heat and melt the thread fed by the puller. As a rule, nozzles are made from brass or aluminum, although more heat-resistant, but also more expensive materials can be used. For printing with the most popular plastics, a brass nozzle is quite enough. The “nozzle” itself is attached to the end of the tube with a threaded connection and can be replaced with a new one in case of wear or if a change in diameter is necessary. The nozzle diameter determines the thickness of the molten filament and, as a result, affects the print resolution. The heating of the hot end is controlled by a thermistor. Temperature control is very important, because when the material is overheated, pyrolysis can occur, that is, the decomposition of plastic, which contributes both to the loss of the properties of the material itself and to clogging of the nozzle.
PrintBox3D One FDM Extruder
To prevent the filament from melting too early, the top of the hot end is cooled by heatsinks and fans. This point is of great importance, since thermoplastics that pass the glass transition temperature significantly expand in volume and increase the friction of the material with the walls of the hot end. If the length of such a section is too long, the pulling mechanism may not have enough strength to push the thread.
The number of extruders may vary depending on the purpose of the 3D printer. The simplest options use a single print head. The dual extruder greatly expands the capabilities of the device, allowing you to print one model in two different colors, as well as using different materials. The last point is important when building complex models with overhanging structural elements: FDM printers cannot print “over the air”, since the applied layers require support. In the case of hinged elements, temporary support structures have to be printed, which are removed after printing is completed.
The removal process is fraught with damage to the model itself and requires accuracy. In addition, if the model has a complex structure with internal cavities that are difficult to access, building conventional supports may not be practical due to the difficulty in removing excess material.
Finished model with PVA supports (white) before and after washing
In such cases, the same water-soluble polyvinyl alcohol (PVA) comes in handy. Using a dual extruder, you can build a model from waterproof thermoplastic using PVA to create supports.
After printing, PVA can simply be dissolved in water and a complex product of perfect quality can be obtained.
Some FDM printers can use three or even four extruders.
Work platform
Heated platform covered with removable glass work table
Models are built on a special platform, often equipped with heating elements. Preheating is required for a wide range of plastics, including the popular ABS, which are subject to a high degree of shrinkage when cooled.
The rapid loss of volume by cold coats compared to freshly applied material can lead to model distortion or delamination. The heating of the platform makes it possible to significantly equalize the temperature gradient between the upper and lower layers.
Heating is not recommended for some materials. A typical example is PLA plastic, which requires a fairly long time to harden. Heating PLA can lead to deformation of the lower layers under the weight of the upper ones. When working with PLA, measures are usually taken not to heat up, but to cool the model. Such printers have characteristic open cases and additional fans blowing fresh layers of the model.
Calibration screw for work platform covered with blue masking tape
The platform needs to be calibrated before printing to ensure that the nozzle does not hit the applied layers and move too far causing air-to-air printing resulting in plastic vermicelli. The calibration process can be either manual or automatic.
In manual mode, calibration is performed by positioning the nozzle at different points on the platform and adjusting the platform inclination using the support screws to achieve the optimal distance between the surface and the nozzle.
As a rule, platforms are equipped with an additional element - a removable table. This design simplifies the cleaning of the working surface and facilitates the removal of the finished model. Stages are made from various materials, including aluminum, acrylic, glass, etc. The choice of material for the manufacture of the stage depends on the presence of heating and consumables for which the printer is optimized.
For a better adhesion of the first layer of the model to the surface of the table, additional tools are often used, including polyimide film, glue and even hairspray! But the most popular tool is inexpensive, but effective masking tape. Some manufacturers make perforated tables that hold the model well but are difficult to clean.
In general, the expediency of applying additional funds to the table depends on the consumable material and the material of the table itself.
Positioning mechanisms
Scheme of operation of positioning mechanisms
Of course, the print head must move relative to the working platform, and unlike conventional office printers, positioning must be carried out not in two, but in three planes, including height adjustment.
Positioning pattern may vary. The simplest and most common option involves mounting the print head on perpendicular guides driven by stepper motors and providing positioning along the X and Y axes.
Vertical positioning is carried out by moving the working platform.
On the other hand, it is possible to move the extruder in one plane and the platforms in two.
SeemeCNC ORION Delta Printer
One option that is gaining popularity is the delta coordinate system.
Such devices are called "delta robots" in the industry.
In delta printers, the print head is suspended on three manipulators, each of which moves along a vertical rail.
The synchronous symmetrical movement of the manipulators allows you to change the height of the extruder above the platform, and the asymmetric movement causes the head to move in the horizontal plane.
A variant of this system is the reverse delta design, where the extruder is fixed to the ceiling of the working chamber, and the platform moves on three support arms.
Delta printers have a cylindrical build area, and their design makes it easy to increase the height of the working area with minimal design changes by lengthening the rails.
In the end, everything depends on the decision of the designers, but the fundamental principle does not change.
Control
Typical Arduino-based controller with add-on modules
FDM printer operation, including nozzle and platform temperature, filament feed rate, and stepper motors for positioning the extruder, is controlled by relatively simple electronic controllers.
Most controllers are based on the Arduino platform, which has an open architecture.
The programming language used by printers is called G-code (G-Code) and consists of a list of commands executed in turn by the 3D printer systems. G-code is compiled by programs called "slicers" - standard 3D printer software that combines some of the features of graphics editors with the ability to set print options through a graphical interface. The choice of slicer depends on the printer model. RepRap printers use open source slicers such as Skeinforge, Replicator G and Repetier-Host. Some companies make printers that require proprietary software.
Program code for printing is generated using slicers
As an example, we can mention Cube printers from 3D Systems. There are companies that offer proprietary software but allow third-party software, as is the case with the latest generation of MakerBot 3D printers.
Slicers are not designed for 3D design per se.
This task is done with CAD editors and requires some 3D design skills. Although beginners should not despair: digital models of a wide variety of designs are offered on many sites, often even for free. Finally, some companies and individuals offer 3D design services for custom printing.
Finally, 3D printers can be used in conjunction with 3D scanners to automate the process of digitizing objects. Many of these devices are designed specifically to work with 3D printers. Notable examples include the 3D Systems Sense handheld scanner and the MakerBot Digitizer handheld desktop scanner.
MakerBot Replicator 5th Generation FDM Printer with built-in control module on the top of the frame
The user interface of a 3D printer can consist of a simple USB port for connecting to a personal computer. In such cases, the device is actually controlled by the slicer.
The disadvantage of this simplification is a rather high probability of printing failure when the computer freezes or slows down.
A more advanced option includes an internal memory or memory card interface to make the process standalone.
These models are equipped with control modules that allow you to adjust many print parameters (such as print speed or extrusion temperature). The module may include a small LCD display or even a mini-tablet.
Varieties of FDM printers
Professional Stratasys Fortus 360mc FDM printer that allows printing with nylon
FDM printers are very, very diverse, ranging from the simplest homemade RepRap printers to industrial installations capable of printing large-sized objects.
Stratasys, founded by FDM inventor Scott Crump, is a leader in industrial plant manufacturing.
You can build the simplest FDM printers yourself. Such devices are called RepRap, where "Rep" indicates the possibility of "replication", that is, self-reproduction.
RepRap printers can be used to print custom built plastic parts.
Controller, rails, belts, motors and other components can be easily purchased separately.
Of course, assembling such a device on your own requires serious technical and even engineering skills.
Some manufacturers make it easy by selling DIY kits, but these kits still require a good understanding of the technology. RepRap Printers
And, despite their "homemade nature", RepRap printers are quite capable of producing models with quality at the level of expensive branded counterparts.
Ordinary users who do not want to delve into the intricacies of the process, but require only a convenient device for household use, can purchase a ready-made FDM printer.
Many companies are focusing on the development of the consumer market segment, offering 3D printers for sale that are ready to print “straight out of the box” and do not require serious computer skills.
3D Systems Cube consumer 3D printer
The most famous example of a consumer 3D printer is the 3D Systems Cube.
While it doesn't boast a huge build area, ultra-fast print speed, or superb model build quality, it's easy to use, affordable, and safe: This printer has received the necessary certification to be used even by children.
Mankati FDM printer demonstration: http://youtu.be/51rypJIK4y0
Laser Stereolithography (SLA)
Stereolithographic 3D printers are widely used in dental prosthetics
Stereolithographic printers are the second most popular and widespread after FDM printers.
These units deliver exceptional print quality.
The resolution of some SLA printers is measured in a matter of microns - it is not surprising that these devices quickly won the love of jewelers and dentists.
The software side of laser stereolithography is almost identical to FDM printing, so we will not repeat ourselves and will only touch on the distinctive features of the technology.
Lasers and projectors
Projector illumination of a photopolymer model using the Kudo3D Titan DLP printer as an example
The cost of stereolithographic printers is rapidly declining, due to growing competition due to high demand and the use of new technologies that reduce the cost of construction.
Although the technology is collectively referred to as "laser" stereolithography, most recent developments use UV LED projectors for the most part.
Projectors are cheaper and more reliable than lasers, do not require the use of delicate mirrors to deflect the laser beam, and have higher performance. The latter is explained by the fact that the contour of the whole layer is illuminated as a whole, and not sequentially, point by point, as is the case with laser options. This variant of the technology is called projection stereolithography, "DLP-SLA" or simply "DLP". However, both options are currently common - both laser and projector versions.
Cuvette and resin
Photopolymer resin is poured into a cuvette
A photopolymer resin that looks like epoxy is used as consumables for stereolithographic printers. Resins can have a variety of characteristics, but they all share one key feature for 3D printing applications: these materials harden when exposed to ultraviolet light. Hence, in fact, the name "photopolymer".
When polymerized, resins can have a wide variety of physical characteristics. Some resins are like rubber, others are hard plastics like ABS. You can choose different colors and degrees of transparency. The main disadvantage of resins and SLA printing in general is the cost of consumables, which significantly exceeds the cost of thermoplastics.
On the other hand, stereolithographic printers are mainly used by jewelers and dentists who do not need to build large parts but appreciate the savings from fast and accurate prototyping.
Thus, SLA printers and consumables pay for themselves very quickly.
An example of a model printed on a laser stereolithographic 3D printer
Resin is poured into a cuvette, which can be equipped with a lowering platform. In this case, the printer uses a leveling device to flatten the thin layer of resin covering the platform just prior to irradiation. As the model is being made, the platform, together with the finished layers, is “embedded” in the resin. Upon completion of printing, the model is removed from the cuvette, treated with a special solution to remove liquid resin residues and placed in an ultraviolet oven, where the final illumination of the model is performed.
Some SLA and DLP printers work in an "inverted" scheme: the model is not immersed in the consumable, but "pulled" out of it, while the laser or projector is placed under the cuvette, and not above it. This approach eliminates the need to level the surface after each exposure, but requires the use of a cuvette made of a material transparent to ultraviolet light, such as quartz glass.
The accuracy of stereolithographic printers is extremely high. For comparison, the standard for vertical resolution for FDM printers is considered to be 100 microns, and some variants of SLA printers allow you to apply layers as thin as 15 microns. But this is not the limit. The problem, rather, is not so much in the accuracy of lasers, but in the speed of the process: the higher the resolution, the lower the print speed. The use of digital projectors allows you to significantly speed up the process, because each layer is illuminated entirely. As a result, some DLP printer manufacturers claim to be able to print with a vertical resolution of one micron!
Video from CES 2013 showing Formlabs Form1 stereolithography 3D printer in action: http://youtu.be/IjaUasw64VE
Stereolithography Printer Options
Formlabs Form1 Desktop Stereolithography Printer
As with FDM printers, SLA printers come in a wide range in terms of size, features and cost.
