Resin printing lets engineers, designers, artists and hobbyists 3D print high-quality objects that they cannot get from filament-based fused deposition modeling (FDM) printers. The process beams ultraviolet (UV) light into a tank of liquid, resin, triggering a reaction that solidifies the resin into a hard plastic. This photo-polymerization happens in a small volume thanks to the narrow ultraviolet beams. As a result, the final object can have much finer details and smoother surfaces than those produced by FDM printers.
Recent innovations have made the decades-old technology of resin 3D printing more accessible than ever. Here’s everything you need to know to get started.
How does a Resin 3D Printer Work?
All resin 3D printers use the same basic physics to turn liquid resin into solid objects. Each slice from the print file is turned into a pattern of ultraviolet (UV) light that shines into a tank of liquid resin. The photopolymer cures into a solid layer and then the bed repositions for the next layer.
In most resin printers, the bed starts one layer height above the source beneath the tank. The bed peels the newly-solidified layer from the bottom of the tank as it rises another layer height to bring in more resin for the next layer.
How Much is a Resin 3D Printer?
Resin 3D printer pricing spans a vast range. Industrial printers from companies like 3D Systems run well into the six-figures. At the other extreme, LCD printers aimed at hobbyists can cost less than two hundred dollars. Resins themselves can vary in price from $20 per liter for basic prototyping to hundreds of dollars per liter for specialty resins.
3D PRINTER RESIN VS. FILAMENT
The difference between resin-based 3D printing and filament-based 3D printing is visible when you pull the object from the bed. Objects produced through resin printing can be more detailed and consistent with fewer printing artifacts. Objects produced with filament printing, however, have better engineering properties and a wider range of materials and styles.
Safety can be an issue with both materials. Like some filaments, resins are irritants and poison hazards. Wearing gloves and having adequate ventilation is a must. Users must be trained in proper safety procedures when handling and disposing of resins.
The ultraviolet light beams in DLP and LCD printers are larger than in SLA printers but still produce finer details than FDM printers. And with finer increments in bed positioning, the thinner layers can produce final objects with no visible layer marks.
Unlike FDM printing, print orientation does not change the strength of resin-printed parts. The curing process is not instantaneous so the solidifying resin chemically bonds with its surroundings. Each new layer bonds with the layer above to create a solid piece without the gaps filament printers leave behind or varying strength depending on orientation.
Although Fused Deposition Modeling (FDM) printers cannot achieve the same level of detail as a resin 3D printer, these printers allow more creative control. FDM printers can be reconfigured — by swapping out nozzles, for example — to better balance quality versus speed for a specific job.
Many different filament materials, such as PLA, nylon or TPU, let you get the right properties for your part. And each filament type can have a range of colors and other additives to deliver a specific look. FDM printing is the best choice for long-lasting objects or anything that needs to be kids-safe.
Disadvantages of Resin
Disadvantages of Resin
IS PHOTOPOLYMER RESIN 3D PRINTING RIGHT FOR ME?
What kind of objects are you printing? Resin works best when producing limited quantities of small, finely-detailed parts that do not need the strength and material options of filament printing.
Are you prepared to operate and maintain the printer? You will be committing to the inconveniences of handling resin safely as well as cleaning and curing parts.
Can you afford the total cost of ownership? More capable printers are not cheap. And resin printing has long-term costs for consumables and replacement parts.
Frequently Asked Questions
Yes, the first step after every print is to rinse away the uncured — including any resin inside the part — before letting the part dry. This is also the point where you remove all traces of the supports. You may need to cure the object further in an enclosure with UV lighting.
Your part may need more typical post-processing beyond this point to achieve the final surface finish.
Many of the skills needed for FDM printing —3D design skills, engineering or aesthetic experience, etc. — apply to SLA printing. But these are different processes using different materials. Consistent success with SLA printing only comes with study and experience. Fortunately, there are plenty of resources out there to help you get started.
Auto manufacturers use SLA printers to prototype dashboards more than a meter across. In that scenario, spending millions on acquisition, operation and maintenance makes sense. At the other extreme, artists and hobbyists who need low-cost options will use FDM printers for their large print jobs.
No. Most photopolymer resins are poison hazards and skin irritants. You should seek medical attention after inhaling, touching or ingesting resin. Finished prints may retain some resin after curing and the solid photopolymer could leach material. As a result, even “biocompatible” resins for medical applications should not be used with food.