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Why is it so complicated to choose your first 3D resin? Basics explained.

Choosing right 3D printing resin basics

Updated on January 29, 2018


Several years before AmeraLabs was founded, when our founder Vaidas was making his first DLP 3D printer, he faced a major question: what type of 3D resin should he pour into his resin tray? Vaidas was completely new and had almost no knowledge about different SLA resin types. It was really hard to find accurate information online. That is why now we would like to share his experience on how to choose SLA 3D printing materials and what factors should one consider when buying one.


Types of 3D printers

When Vaidas started to search for his own 3D printing resin, these materials brought a lot of uncertainty to him. Each manufacturer produces somewhat different formulations with variable contents of light blockers, catalysts and other components. To avoid confusion and mistakes materials are adapted to different types of 3D printers or even to distinct devices. This is because resin 3D printers are extremely different from 3D resins point of view. Each typically possesses significantly different light source, whose characteristics are critical for 3D resin formulation. Generally speaking resin 3D printers use the following light sources:

LCD LED Printer Video DLP Projector
Laser
LCD displays with LEDs (MSLA) Beam/UV projectors (DLP) Laser-based systems (SLA)

Anycubic, Elegoo, Epax, Kudo3D, Longer, Phrozen, Prusa, Uniz3D, Wanhao, Zortrax and similar 3D printers

Asiga, Autodesk Ember, Kudo3D Titan, Phrozen One, 3D Labs Totem and similar 3D printers

FormLabs Form 3, Peopoly Moai and similar 3D printers

All the above possess three main technical differences:

3D printing XY resolution 3D printing light power 3D printing wavelength
XY printing resolution (µm). Light power (mW/cm2). Wavelength (nanometers) of the emitted light.

Let’s review each difference one by one so that you could understand how each one could help you when selecting the right 3D resin type.

XY and Z resolutions

Firstly, resin 3D printers can have fixed or variable XYZ printing resolutions. DLP 3D printers typically have fixed or adjustable XY resolution whereas 3D printers based on LCD/LED or lasers usually have fixed one. It is worth mentioning that XY resolution means the size of individual pixel in X and Y axis for LCD/LED and DLP systems. Whereas for laser systems that is laser spot diameter. On most machines Z resolution or layer height can be quite easily adjusted and can start from practical thickness of 10 um and reach 100 um or even more.

XY and Z resolutions can affect 3D printing materials you use. The key point here is pigment or dye concentration in the selected material. For instance, if you own 3D printer with high XY resolution (35‑40 um and less) and prefer to print with layers of 50 um and less, 3D resins with low concentration of such light blockers will result in severe light bleeding or light scattering. These phenomena reduce details of your prints as light penetrates material too deeply or deviates from intended straight trajectory. On the other hand, if you have lower XY resolution printer and aim for fast printing with thicker layers, i.e. around 75‑100 um, lower levels of dyes and pigments are preferred.

To fully exploit your XY and Z resolutions you must use material with proper pigment or dye concentration and make sure that it is tested in similar conditions.

Light wavelength

Light wavelength differs quite a bit among resin 3D printers.

  • SLA lasers typically emit ~395 nm light waves.
  • LCD/LED (also called MSLA) systems: ~405nm for UV based versions and royal blue ~450nm for daylight versions.
  • DLP beam projectors typically emit light from 400 nm up to 680 nm light waves, whereas UV projectors use 405 nm.

The shorter the wavelength, the more energy photons carry. Therefore, developers of 3D resins choose appropriate catalysts that initiate transition from liquid to solid based on wavelength of targeted light sources. Thus, if you take one material that works very well with 395 nm light and use it with 405 nm wavelength, you simply cannot expect identical performance between these two. Actually, you will probably end up with longer exposures or your 3D resin will not work at all. Consequently, when considering different SLA resin types you must make sure that it is compatible with the wavelength of light source of your 3D printer.

Power of light

Due to different light sources of resin 3D printers, power of emitted light differs as well.

  • Laser based SLA printers typically produce 100-250 mW of light power to their laser spot.
  • UV DLP projectors produce around 20 mW/cm2 and beam projectors can output even more than 20 mW/cm2. Moreover, if DLP based 3D printer has variable XY resolution, its power also varies based on selected XY resolution. If you increase resolution, i.e. move projector closer to resin tray, you also increase power to 1 cm2. If you lower resolution, i.e. move projector away from the tray, you decrease power to 1 cm2.
  • LCD/LED systems provide lowest power output, because LCD filters absorb most of LED light.

Each type of light source requires different SLA resin types. Laser based SLA systems are usually the most powerful. So, 3D printing materials for such systems are also less reactive to compensate that. DLP systems are in the middle, but for efficient printing 3D resins are also applied to this power range. The least powerful LCD/LED systems require 3D resins to be reactive and fast in low-power conditions. Therefore, resins for LCD/LED systems are typically named after “rapid” or “fast”. For example, our AMD-3 resin is formulated for LCD printers.

It’s not recommended to use 3D resins that are designed for a specific light source and power with other types of light sources. For example, you cannot take fast material and use it with high-powered light sources (for example, lasers). You will struggle to control the process, calibrate proper exposure times or even get system working. On top of that, you might even damage your 3D printer’s VAT. Nonetheless, there are types of 3D resins on the market that due to balanced reactivity might perform quite well with DLP and LCD/LED systems. One example is our DMD-31 dental 3D printing resin. It works on both DLP and MSLA resin 3D printers. All in all, you must be aware if the type of 3D resin is designed for the type of 3D printer and light power that you have.

Is there anything else?

Although, there are quite a few things to consider when choosing your 3D printing material, you can vastly decrease uncertainty by considering the above mentioned points. Just by assessing these you will be able to select correct material for your needs. Finally, do not forget that your application dictates the type of the material as well as its properties. Also consider what you are going to print before considering different SLA resin types.

If you are still not sure what type of 3D printing resin is for you, do not hesitate to drop us an email to:

go to contacts page to get our contacs

Try before you buy

To make your selection easier, AmeraLabs provides you with unprecedented sample opportunity. Purchase a 250ml sample of our material and, if it does not work as expected, we will issue a full refund. You will not have to send anything back!

If you have some spare time, check out check our shop and other blog posts:

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