What is that smell?

The smell you’re noticing could be due to the release of Volatile Organic Compounds (VOCs) during the 3D printing process. Both FDM and resin 3D printers can generate VOCs that have distinctive odors.

For FDM printers, the smell can vary depending on the type of filament being used. For example, PLA often has a sweet smell, while ABS can produce a more unpleasant odor.

Resin printers, on the other hand, can produce a strong and often unpleasant smell due to the chemicals used in the resin. This smell is particularly noticeable during the printing and post-processing stages.

Some of the VOCs released during 3D printing include Alpha-pinene, Lactide, Limonene, and Propylene Glycol, which are common in foods, fragrances, and everyday goods. However, hazardous VOCs like Dioxane, Formaldehyde, and Styrene, which have been linked to an increased risk of cancer, can also be emitted.

It’s important to note that just because you can’t smell anything doesn’t mean there are no VOCs present. Some VOCs are odorless but can still be harmful. Therefore, it’s recommended to use proper ventilation or filtration systems when 3D printing, especially when printing indoors.

Amazing reference: https://4dfiltration.com/resources/3d/3d-printing-air-quality-roundup

How can I do a working curve?

To create a photopolymer “working curve,” which establishes the relationship between the depth of a photocured resin and the corresponding light dose, you can follow these general steps:

  1. Gather the necessary materials:

    • Photopolymer resin
    • Light source (e.g., projector, laser)
    • Power meter (to measure light intensity)
    • Thickness measurement tool (e.g., micrometer, caliper)
  2. Prepare the resin:

    • Ensure the resin is properly mixed and free from any contaminants.
  3. Set up the experiment:

    • Place a layer of the resin on a substrate or in a container.
    • Position the light source at a fixed distance from the resin surface.
    • Adjust the light intensity and exposure duration to achieve different light doses.
  4. Measure the thickness:

    • After each exposure, measure the thickness of the cured resin using the thickness measurement tool.
    • Record the corresponding light dose for each thickness measurement.
  5. Plot the working curve:

    • Create a graph with the light dose (x-axis) plotted on a logarithmic scale and the cured resin thickness (y-axis) plotted on a linear scale.
    • Plot the data points obtained from the measurements on the graph.
  6. Analyze the working curve:

    • Examine the shape of the curve. Ideally, it should be linear when plotted with a logarithmic dose axis and a linear depth axis.
    • Determine the slope of the curve, which represents the depth of light penetration (Dp).
    • Identify the critical dose for gelation (Ecrit), which is the x-intercept of the working curve.
  7. Use the working curve for exposure settings:

    • With the working curve, you can interpolate the dose required to cure a layer of a specific thickness.
    • Use the working curve to determine the optimal exposure settings for your desired resin thickness.

Remember that the specific process and parameters may vary depending on the type of photopolymer resin and equipment you are using. It is also important to note that standardization efforts are underway to establish best practices for working curve measurements.

Learn more:

  1. How to Take a Working Curve Measurement and Create Exposure Settings From It : 9 Steps (with Pictures) - Instructables
  2. Making the Working Curve Work for You - UV+EB Technology
  3. Resin 3D-printing: Ec, Dp, cure depth & more explained

What stuff do I need to safely print with resin?

To safely print with resin, you will need the following items:

  • Resin Printer: A resin 3D printer is necessary for printing with resin. There are various models available in the market, so choose one that suits your needs and budget.
  • Resin: You will need resin specifically designed for resin 3D printing. There are different types and colors of resin available, so choose the one that is suitable for your project.
  • Resin Vat: A resin vat is used to hold the resin during the printing process. It is important to have a clean and properly functioning resin vat for successful prints.
  • Build Plate: The build plate is where the print is attached during the printing process. It is important to ensure that the build plate is clean and level before starting a print.
  • UV Light Source: Resin 3D printers use UV light to cure the resin and solidify the prints. The printer should have a built-in UV light source or be compatible with an external UV light source.
  • Safety Equipment: It is crucial to have the following safety equipment to protect yourself while working with resin:
    • Nitrile gloves: Wear disposable nitrile gloves to protect your hands from direct contact with the resin.
    • Safety glasses: Wear safety glasses to protect your eyes from any splashes or spills.
    • Respirator: Use a respirator with appropriate filters to protect yourself from inhaling any fumes or particles.
  • Ventilation: It is important to have proper ventilation in the printing area to minimize exposure to fumes. If possible, set up the printer in a well-ventilated area or use a ventilation system to remove fumes.
  • Cleaning Supplies: You will need cleaning supplies to clean the resin vat, build plate, and any spills or drips. Isopropyl alcohol (IPA) is commonly used for cleaning resin prints and equipment.
  • Curing Station: After printing, the resin prints need to be cured to ensure their full strength and stability. You can use a UV curing station or a UV light box for this purpose.
  • Storage and Disposal: Properly store the resin and dispose of any waste resin according to local regulations. Avoid pouring resin down the drain or into the ground.

Remember to always follow the manufacturer’s instructions and safety guidelines when working with resin. If you have any further questions or need more specific information, feel free to ask!

What's the difference between SLA and DLP?

SLA (Stereolithography) and DLP (Digital Light Processing) are two different technologies used in resin 3D printing.

SLA uses a laser directed by a galvanometer to cure the resin. The laser can be moved anywhere along the x and y axes, allowing for precise shaping of the printed object. SLA is known for its high precision and is often used for applications that require fine details.

On the other hand, DLP uses a projector to shine UV light onto a tank containing the resin. The UV light is redirected by tiny mirrors to turn each pixel on or off, creating the desired shape. DLP is generally faster than SLA, especially when printing larger parts or multiple parts at once.

Both SLA and DLP technologies require post-processing steps, such as cleaning the printed object to remove excess resin and post-curing to fully cure the resin.

Why would I use a resin DLP printer over a Polyjet printer?

Resin DLP printers are often preferred over Polyjet printers for several reasons:

  • Speed: DLP printers are generally faster than Polyjet printers, especially when printing larger parts or multiple parts at once. This can significantly reduce the overall printing time.

  • Cost: Resin DLP printers are typically more affordable compared to Polyjet printers. This makes them a more cost-effective option, especially for small businesses or individuals on a budget.

  • Resolution: DLP printers can achieve high levels of detail and precision in the printed objects. The UV light projected by the DLP projector allows for precise shaping of each pixel, resulting in fine details and smooth surfaces.

  • Material Options: Resin DLP printers offer a wide range of resin materials to choose from, including different colors and properties. This allows for greater flexibility in selecting the most suitable material for specific applications.

  • Post-Processing: Both DLP and Polyjet printers require post-processing steps, such as cleaning and post-curing. However, DLP printers generally have simpler post-processing requirements compared to Polyjet printers, which can involve additional steps like removing support material.

It’s important to note that the choice between a resin DLP printer and a Polyjet printer ultimately depends on your specific needs and requirements. It’s recommended to consider factors such as budget, printing speed, resolution, material options, and post-processing requirements when making a decision.