If you own a desktop 3D printer, chances are you’ve shopped around and tested various plastic filaments from different suppliers. Each offers their own hue of color, tempting buyers with different shades and tones. While printing a household item in neon green or ultra-transparent purple may not go with your current kitchen décor, painting it is always an option. Everyone’s striving for more realism in their prints so it’s only natural that the market responded with an array of specialty filaments for either practical or aesthetic needs.
Specialty 3D printing filaments aren’t just about new colors, they’re also about utility. In the realm of fused deposition modeling (FDM), the industry is moving forward with inventing new filaments that solve practical needs. Whether you’re trying to 3D print biodegradable products, create a mold for lost wax casting, or reproduce an ancient sculpture in bronze, there’s a filament for that.
Below are some of the latest specialty 3D printing filaments on the market today, each offering their own set of characteristics and nuances. Some have evolved, making them quite easy to use for the newbie. Others require a degree of patience, experience, and skill.
Metal 3D printing filaments: the holy grail for desktop FDM
At the moment, the latest metal 3D printing filaments are as close as you can get to the real thing. Several companies have combined micron-sized metal particulate or powder with plastic, creating a class of filaments that closely simulate the look of various metals. Proto-Pasta was one of the first to combine PLA plastic with 15% chopped carbon fibers. Carbon Fiber PLA is extremely popular, exhibiting increased rigidity beyond standard PLA or ABS. In wake of its popularity, the team also expanded their offerings to include Stainless Steel (PLA plastic with powdered steel) and Magnetic Iron PLA (ground iron powder with PLA).
Over in the Netherlands, ColorFabb continues to innovate with their own lineup of metal-like filaments. The company offers BrassFill, BronzeFill, and CopperFill, all of which are designed to work without the need for a heated build plate.
Each combines plastic with powderized metal, providing users the ability to create parts that almost look laser sintered. There’s also tungsten or bismuth metal 3D printing filament known as GMASS. This filament combines ABS and tungsten or bismuth; formulated for desktop 3D printers. It features “metal-like” characteristics that include weight, feel, and density. GMASS has grown in popularity for innovative medical engineering applications. It’s perfect for sporting goods, lab equipment, vibration dampening, and x-ray shielding. Developed by Tuner MedTech, these filaments are used for medical grade products. You can also use GMASS to 3D print radiation shielding. You know, just in case you want to print an Iron Man chest plate for use at the dentist’s office.
Metal filaments require a bit more TLC than standard PLA or ABS. Most desktop 3D printers are configured and sold with brass nozzles. While they’ll work fine, metal filaments dramatically increase their wear and tear. Fine metal particles that are constantly heated, cooled, and pushed through the tip of a brass nozzle will dramatically decrease its performance life. If you plan on doing a lot of printing with metal filaments, stainless steel nozzles are harder than brass and more resistant to internal abrasion.
There are other factors to consider as well. Direct drive 3D printers reportedly handle metal filament better than Bowden designs, making it easier to control filament flow and extrusion rates. Temperature, print speed, and retraction settings should also be experimented with depending on your unit.
Metal 3D printer filament also requires extensive post processing. A final object will have the appearance of cast metal rather than true metal. Extensive sanding, polishing, and buffing will reduce the plastic surface and help bring out the metallic shine. There are a number of finishing techniques that can be used including wire brushing, polishing, rock polishing, and wheel polishing. Using polishing compounds or creams is also recommended to help bring out the object’s luster.
There is hope for those who don’t feel like post-processing. Kickstarter company Sinterhard is developing metal 3D printing filament that can be hardened and metalized using a sintering process. These filaments allow users to 3D print items that are furnace ready so they can be debinded and sintered into solid metal objects. Using 316 Stainless Steel or Aluminum Powder combined with PLA or ABS, Sinterhard filament replaces the need for Metal Injection Molding (MIM) or investment casting. Known as the MPF process (Metal Printed Filament), an object 3D printed with Sinterhard is first debinded with solvent and then placed in a furnace to achieve the sintered metal process. Sinterhard is also working on replicating this for ceramic filament.
PET+ filament
MadeSolid has released its PET+ filament, combining easier printability with the strength characteristics of ABS. The filament is tough yet extremely flexible and perfect for engineering grade components in robotics, mechanical assemblies, and wearable devices. In flexibility strength tests, PET+ is able to handle over twice the pressure when compared to ABS. It’s more flame resistant than either PLA or ABS and offers good adhesion capabilities during prints; eliminating the need for a heated platform.
Amphora Polymer filament
Leading manufacturers ColorFabb, Taulman3D, TripTech Plastics have partnered with Eastman to offer Amphora 3D polymer filament. The material is approved by the FDA for food contact applications and is also BPA-free. This low-odor, styrene-free material allows users to create parts that are not only attractive in finish, but also functional, tough, and durable. They combine superior melt strength with dimensional stability, allowing for stronger parts that exhibit great detail.
Advanced Composite Filament
Avante FilaOne composite filament allows you to create engineering grade prototypes and parts that are easier to print with than Nylon. Strong and impact resistant, it requires a heated print bed but doesn’t emit toxic fumes. It’s also not affected by humidity or contact with water. FilaOne requires a special adhesion surface to print with which can be purchased separately. Perfect for engineering prototypes or parts, this filament features high stiffness and tensile strength.
Low Friction Filaments
IGUS iglidur I180-PF is the first filament developed with 50x more abrasion resistance than traditional 3D printer filaments. Perfect for self-lubricating bearings or other low-friction prototypes, this material prints similar to ABS; requiring a heated build plate and hot end ranges between 220 – 250 °C. I180-PF is commonly used for designs that require repetitive movement or where surface contact between parts plays an important role.
Conductive Filament
For the world of electronics, several companies have already released conductive ABS and PLA filament. Conductive ABS and PLA is great for small LED or low current draw circuits. It provides anti-static or electromagnetic interference shielding for objects. Conductive filament is semi-flexible, offers good strength, but requires more attention to proper layer adhesion than standard PLA.
Wood Filaments
The original wood 3D printing filament was developed by Kai Parthy and is also known as “Laywoo-D3”. Combining recycled wood fiber with binding polymers, Laywood was an instant hit. Wood filament offers a key advantage for unique objects: by lowering or raising the extrusion temperature throughout the print, one can achieve varying wood finishes along the surface of an object for “tree ring” effects. Subsequently, varying the print temperature will also achieve smoother or rougher surface characteristics. Wood filament is fairly easy to print with, requiring no heated bed and slight changes in print settings to achieve the desired look. It barely warps and can be post processed using sanding, grinding, staining, or painting. Make sure to work within the extrusion temperature ranges – wood filament burns and tars if overheated, leading to excessive clogging.
In 2015, companies began to develop an array of new wood and plastic combinations. There’s cheery wood, light wood, flexible wood, and a wood-PLA hybrid. ColorFabb took it a step further, recently releasing BambooFill and CorkFill to their lineup of specialty filaments. It’s become a standard material offered by suppliers including Zen Toolworks, Gizmo Dorks, HatchBox, Alchement, Sainsmart, and eSun.
Microporous Filaments
These filaments are still somewhat in the experimental stage but are available for sale. Developed by Kai Parthy, the PORO-LAY line is ideal for printing rubber polymer parts that have micro-porous features. It includes GEL-LAY, a jelly like material for fabricating artificial body parts, floating objects, or flexible products. LAY-FOMM is ideal for soft rubber applications such as sponges, micro-foam, elastics, or ink-absorbing material. These materials are made with a combination of PVA and rubber-elastomeric polymers. Once submersed in water, the PVA disappears from the model. As a result, the object will lose its rigidity and strength but increase in flexibility and elasticity.
Nylon
In the early days of desktop 3D printing, nylon line from weed whackers and lawn trimmers were used as filament. While it generally worked, the added ingredients at that time would ruin extruder assemblies and nozzles. The recipe soon evolved, with additives removed that ultimately harmed the printer. Nylon has been around for some time for 3D printers. Particularly, the Taulman Nylons.
Biodegradable Linen Filament
BioFila is developed by twoBEars and is 100% biodegradable, allowing it to breakdown in landfills or soils. Made from Lignin, this material is found in the cellular walls of plants. Combined with polymers, it forms a unique filament that’s harder and more durable than PLA. Made in Germany, BioFila produces prints with a unique satin appearance. Surface sheens can be adjusted depending on the print temperature. BioFila is also made with Silk as an option, providing the same features as linen but known for its smooth, shiny, liquid-like qualities.
Mold Fabrication Filament
For the casting crowd, MoldLay allows you to 3D print plastic molds with wax-like properties for mold casting, lost wax casting, and in some cases, investment casting. It extrudes in the 170 – 180° C range, is almost warp-free, and can be printed without a heated bed. Printed molds can be sanded and smoothed beforehand for use with simple resins, concrete, or even silica and plaster. Prior to beginning the cast process, the molds should be pre-treated using an old baking oven; heated to 270° C.
Cleaning Filament
Performing intense surgery on your nozzle or heating assembly to remove clogs is never a dull moment. While there are various ways to go about cleaning your nozzle, eSun’s cleaning filament makes the process simple. Just feed several inches of cleaning filament through your printer between 235 and 250 ° C. As it passes through the nozzle it will help dislodge or remove old filament matter. Cleaning filament is great for instances where you only have one nozzle but have to switch through colors or materials. It’s also a wonderful way to clean out your nozzle after using wood or metal filaments; helping to remove burnt fiber or metallic particulate.
Specialty filaments expand desktop 3D printing capabilities
In terms of specialty filaments, the material itself now has the power to make the part; offering new options for the look, feel, and performance of your objects. Your prototype piston assembly that you want to show to clients is no longer bound by your ROYGBIV taste in materials. Rather, it’s produced in a realistic metallic filament, complete with lustrous qualities. With a variety of new specialty filaments already in the queue for 2016, your 3D printing just got a makeover.
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