1.8. Disadvantages

Requires post-processing (support removal, additional curing)

Additive manufacturing techniques, like stereolithography, often involve creating parts that need further processing after the printing is done. This includes removing support structures that were necessary for the printing process and performing additional curing to ensure the part is fully solidified and stable. The need for these extra steps can increase the time and effort involved in completing a project.

Think of baking a cake: after it comes out of the oven, you cannot just put icing on it; you often need to let it cool and sometimes shape it to prevent any mess. Similarly, the 3D printed object requires 'cooling' and finishing before it's ready for use.

Mechanical properties depend on resin formulation and may degrade under light or humidity.

The mechanical properties of 3D printed parts are closely tied to the specific formulation of the resin used during printing. Different resins have varied strengths, flexibility, and durability characteristics. Moreover, parts made from these resins can weaken if exposed to sunlight or humidity over time, which can be a significant drawback, especially in applications requiring durability.

Consider different types of plastics used for storage containers: some are rigid and can withstand heavy items, while others are flimsy and break easily under stress. Similarly, the type of resin used in 3D printing significantly affects how strong or fragile the final product will be.

Part brittleness and sensitivity to UV exposure.

Many 3D printed parts, especially those made from photopolymers, have a tendency to be brittle. This means they can break or crack under stress rather than bending. Furthermore, if these parts are exposed to UV radiation, they may degrade more quickly than other materials, significantly reducing their lifespan and usability.

Imagine a thin piece of glass. If you drop it, it can shatter into pieces instead of just bending. Similar to glass, many 3D printed parts may crack or break under pressure, limiting their practical applications if they're not handled with care.

Photopolymer resins can be expensive and offer limited thermal/mechanical resistance.

Photopolymer resins used in stereolithography printing can be more expensive than other materials, which can be a concern for budget-conscious projects. Additionally, these resins often have limitations when it comes to their ability to withstand temperature changes or mechanical stress, which may limit their use in certain environments, such as high-heat applications.

Think of using a fancy but delicate dinnerware set for everyday meals. While it looks nice, it’s expensive and you can’t use it for every occasion or type of food, just like certain photopolymer resins can't be used in all practical applications due to their limitations.

Support structures are needed and can impact finishes on contact areas.

In the stereolithography process, support structures are often required to hold the part in place during printing. However, these structures can leave marks or affect the surface finish of the areas they were attached to once removed, potentially requiring additional finishing work to achieve a smooth appearance.

Consider a sculpture that is built on a temporary support frame. Once the support is taken away, there may be marks left on the sculpture that require sanding or polishing to get it back to a flawless state, similar to how support structures can affect 3D printed parts.

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