How Resin Printers Work (SLA, DLP, & LCD)

How Resin Printers Work (SLA, DLP, & LCD)

Jason Jason
4 minute read

When you think of 3D printing, you might picture spools of plastic filament. However, there's another, more liquid-y side: resin printing. What is it?

Resin 3D printing, or vat photopolymerization, is essentially magic using liquid and light. It transforms liquid resin into solid forms, using a source of light. We've got a few different players in this space: SLA, DLP, and LCD.

Why the buzz around resin printing? It's all about the details! Gamers love it for intricate game pieces, while jewelers find it invaluable for detailed designs. Even the medical and dental sectors are catching on, crafting custom models and molds for patients.

Resin 3D Printing Methods

Stereolithography (SLA)

Let's hop into our time machine for a moment. Back in the 1980s, Charles Hull came up with SLA. Imagine a UV laser drawing designs on a layer of liquid photopolymer resin. Once the resin meets the UV light? It transforms into a solid. This dance of light and liquid continues layer by layer, creating a 3D object.

Now, SLA boasts some great perks. Picture a flawless, smooth print without those lines we often see in standard 3D prints. And guess what? No worries about water sipping in; these prints are watertight! The cherry on top? The choice in materials. From transparent to tough to even ceramic-filled resin, SLA’s got it all.

Digital Light Processing (DLP)

If SLA was like a pen sketching out on resin, DLP's like a stamp. Instead of drawing, DLP uses digital projection to flash a 2D pattern of your object on the resin, curing an entire layer at once. This means DLP could potentially be a speed demon compared to its SLA cousin.

Though they have a common goal, DLP devices operate a bit differently. The machinery sits beneath a vat of resin. Each time a layer is done, the build platform moves up. The real hero in DLP is the digital micromirror device. These tiny mirrors guide the light to the resin, playing a huge part in the print's resolution.

Liquid Crystal Display (LCD) / mSLA

You might be noticing a pattern here. Just like DLP, LCD, or mSLA, cures entire layers in one go. The major difference? The kind of light show happening. Instead of digital projectors, LCD printers use LEDs paired with an LCD screen.

Wondering about the print resolution? In LCD, the screen size and pixel count are your clues. If you're all about the specs, simply divide the screen length by its number of pixels.

Practicalities of Resin 3D Printing

  • Storing Resins: Handling liquid gold (or resin) means proper storage. Keep it away from UV light and store it in dark spots. Brands recommend opaque containers, like those made from HDPE or polypropylene. And if you're keeping it for the long haul? Regularly shake them to keep the mixture right.
  • Handling Resins: Safety first, folks! Uncured resins are toxic. So always glove up, and maybe even put on some goggles if you're feeling splashy. If you're sensitive to smells, working in a ventilated area helps, though most resins are formulated to be odorless or low odor.
  • Cleaning and Post-processing: Freshly printed? It's bath time! Objects go straight into isopropyl alcohol (IPA) or similar solvents for cleaning. After their rinse, the next stop's UV light for post-curing. Why? To make sure your print's truly solid.

Disposal of Resin

Never ever send liquid resin down the drain! For leftover resin in the vat, pour it back into the bottle for reuse. Resin waste like supports and failed prints? Ideally, cure them first, then dispose as per your local regulations.

Wrapping Up

Resin 3D printing is an innovative blend of science and art. With its ability to create intricate designs, it's no wonder it's made waves in numerous industries. If you're a hobbyist or a professional, there's something in the world of resin printing waiting for you.

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