Fused deposition modeling (FDM), Stereolithography (SLA) and Selective laser sintering (SLS) are the most dominant 3D printing processes. Fused deposition modeling uses thermoplastic filament, Stereolithography uses liquid resin and Selective laser sintering uses thermoplastic powder.
In recent times, SLS has slowly overtaken SLA to become the second most popular 3D printing technology. FDM is the most used printing technology, with over 71 percent of companies polled in a recent survey saying they use it. Source
The primary reason for the popularity of FDM printing is filament is much easier to work with than either resin or powder. It also helps that FDM printers are up to three times cheaper than SLA and SLS printers!
But how does filament compare against resin or powder?
The biggest upside of filament is that it is easy to work with. It has a low melting point and does not require as much post-processing or clean up as resin printing. It is also cheaper and faster to work with.
The downside to FDM is that it produces lower resolution prints that are not as strong or durable due to anisotropy. Anisotropy is the weak inter-layer bonding of 3D printed parts. There are many different varieties of filament but these are the most common.
|PLA||Easiest to use. Biodegradable.Food safe.Strong.No odor.||Brittle and prone to heat and chemical exposure.|
|ABS||Strong and durable.Heat and impact resistant.||Harder to print with.Needs a heated print bed and ventilation.|
|Nylon||Strong, durable and light.Heat and impact resistant.Some flexibility.||Hard to print with.|
|PETG||Improved strength and flexibility.Food safe.Transparent.Odorless.||Scratches easily.|
|TPE, TPU, TPC||Flexible polymers.Durable and impact resistant.||Hard to print with.|
|HIPS||Typically paired with ABS for support structures since it’s soluble.||Limited application.|
|PVA||Support material that dissolves in water.||Difficult to use.|
|Composites||Filament reinforced with carbon, glass or other composite to make it stronger and more durable.||Best used with expensive printers. Quickly wears out printer nozzles.|
Selective laser sintering is the second most used printing process after FDM. SLS is more commonly used by engineers and manufacturers to produce strong functional parts. It is very useful for creating complex parts because it does not require support material.
SLS printing is isotropic. This means that layers bond at a chemical level, giving you parts that are stronger regardless of orientation. Selective laser sintering uses nylon or nylon based composites.
Invented in 1986, Resin 3D printing is the first printing technology. Although it has fallen behind other printing processes, SLA printing produces parts with higher resolution, more detail and better finish than FDM.
Like SLS, SLA is isotropic meaning structural weakness from inter-layer bonding is not a problem as it is with FDM printing. Resins come in liquid form of which there are several types.
|Standard||High resolution finish.||Quite brittle.|
|Transparent||Produces the clearest parts.||Not very strong.|
|Jewelry||Allows for greater detail.||Brittle and not very strong.|
|Medical||Hard resin used in the dental field.||Very expensive.|
|Plant based||These are made with plant oils as a base. They’re a more environmentally friendly resin.||Brittle and not very strong.|
|Flexible||As flexible as TPE filaments. Can be bent or compressed.||Loses flexibility when exposed to light.|
For more on resin printing, check out our post ” What Is Resin 3D Printing? Resin vs FDM: Which Is Better!“
Also, check our Does 3D Resin Expire? Can You Still Use It !
Filament gives you speed, ease of use, versatility and allows you to print at the cheapest price. This is why it excels as a prototyping tool. Resins and powders give you greater strength, durability and resolution. This is why they excel in building end-user parts.