The Chemistry of 3D Printing
3D printing is exploding with new filaments with unique properties. From high temperature resistance to electrical conductivity, there is a wide range of filaments to meet the needs of 3D printers.
In this blog I’ll present the chemical background on the most popular filaments, along with the suggested printing temperatures and settings.
PLA: Polylactic acid – 3D printing chemistry
PLA is a favorite filament for beginning 3D printers. It is made from food sources such as corn starch in the USA, and other food sources around the world.
PLA is a forgiving filament that many filament companies make. Exotic filaments are often a blend of PLA binder with very fine mix of other materials.
PLA does absorb moisture from the air and it is good practice to keep it in an airtight container with desiccant when not printing. PLA is good for about 6 months before it has to be dried out. If you hear the filament popping and crackling, or see steam when it feeds out of the extruder, your filament will need to be dried out.
Printing Temp: 180 – 210 C Bed Temp: PLA can print on an unheated bed, but to prevent warping you can print 40 – 70 C bed temp.
PLA/PHA: Polylactic acid & polyhydroxyalkanoate – 3D printing chemistry
This filament is two-part blend of PLA and polyhydroxyalkanoate (PHA).
PHA gives PLA more flexibility and strength. PLA/PHA is less prone to warping than PLA by itself. It is popular alternative to plain PLA, and can come in a wide variety of colors. Both PLA and PLA/PHA are biodegradable.
Printing Temp: 190 – 210 C Bed Temp: 40 – 70 C
ABS: Acrylonitrile butadiene styrene – 3D printing chemestry
As a petroleum-based plastic, ABS requires ventilation to comfortably use. ABS is commonly found in mass-produced toys and car parts. ABS is known for warping, so you will need an aggressive build surface or glue to hold it to the build plate. In my exotic filaments course I discuss how ABS is used with HIPS support material. ABS can be polished with vaporized acetone, but that process carries the risk of explosion.
Print Temp: 230 -250 C Bed Temp: 110 C
HIPS: High Impact Polystyrene – 3D printing chemistry
HIPS prints at a similar temperature as ABS. Unlike ABS HIPS can be disolved with an organic solvent, D-limonene. HIPS can be used as a primary filament, or as a support material for ABS. In my course you can learn how to use HIPS as a dissolvable support material.
Print Temp: 230 – 250 C Bed Temp: 110 C
PVA: Polyvinyl Alcohol – 3D printing chemistry
PVA is a water-soluble material, so it is not suited as a primary printing material. PVA is used for printing supports. PVA is great for complex prints that have internal supports that are difficult to remove. Unlike HIPS, it does not require special solvents to remove supports. PVA is used in dishwasher and laundry soap pods because it dissolves in warm water. With PVA you can print supports for complex shapes, than dissolve the supports away with minimal mess compared to HIPS. PVA is often printed as a support material for PLA.
Print Temp: 190 – 220 C Bed Temp: 40 – 70 C
Nylon – 3D printing chemistry
A petroleum-based filament that is popular for industrial uses. There are many different blends of Nylon, so you will have to look at the technical specs of your Nylon before printing. Nylon can be a difficult filament to print in, so practice before printing important parts.
Nylon must be kept in an airtight container with desiccant at all times. Nylon is notorious for absorbing moisture from the air in a short amount of time.
Print Temp: Varies depending on blend. Bed Temp: Varies depending on blend.
To learn more about the different types of filaments, you can sign up for a course on exotic materials.
This course offers an overview of all the exciting new filaments like wood and conductive PLA’s. When you complete the course, you will receive a signed certificate by Stan, a licensed science teacher.