Reader Response Draft #3 (Edited)

The webpage “Guide to Stereolithography” from Formlabs (2015) introduces the Stereolithography (SLA) technology. Stereolithography, also referred to as vat photopolymerization or more simply resin 3D printing, is an additive manufacturing technique that uses a focused light source to polymerize a photoinitiated liquid resin into a solid. The SLA may be classified as the most widely used Rapid Prototyping (RP) method largely because it has many advantages when compared with other 3D printing methods. Advantages such as higher precision and resolution (like 1 μm for MicroSLA and 10 μm for SLA as compared to 100 μm for Fused Deposition Modelling (FDM) another type of 3D printing technology) and complex internal structures in the made parts (Gardan, 2015). Yet, like any other technology, it has its shortcomings, which will be presented later. The main disadvantages include the very limited range of photopolymerisable materials available, their relatively high price and possibly the requirement of additional steps after the fabrication process, to enhance the physical characteristics or extract excess uncured materials. (Martinez et al., 2018). As such, the Stereolithography (SLA) Resin 3D Printer is able to produce durable prototypes and its cost-benefit ratio is high, increasing its marketability.

The Stereolithography (SLA) process’s ability to quickly transform Computer Aided Drawings (CAD) models into functional prototypes within a few hours makes it very effective for Rapid Prototyping (RP) applications. This method is achievable by using a focused light source to cure the liquid resin, layer by layer onto an inverted board, then turning it into a solid (Kushwaha et al., 2022). Parts and prototypes printed by SLA are robust and are able to withstand continuous friction forces over time. Due to its printing process, the resin particles are compactly packed, creating isotropy, which means that materials are uniform in all directions. As a result, the parts are durable and long-lasting, thus lowering the maintenance costs of parts (Hague et al., 2004). Such characteristics encourage users to opt for SLA for applications requiring reliability and precision, enhancing its market competitiveness.

When compared to Fused Deposition Modelling (FDM), Stereolithography (SLA)’s ability to achieve superior surface finishes stands out as a key differentiator. As FDM utilises a layer-by-layer ‘hot glue gun’ method that will produce layer lines upon close inspection of the printed part. In FDM, layers of melted thermoplastic are fused to produce a 3D shape by being extruded onto a build platform (FDM vs SLA - 3D Printing Process Breakdown, 2024). These parts would then need extra post-processing in order to achieve a surface finish which is acceptable, which would lead to a higher production cost (FDM vs. SLA vs. SLS: 3D Printing Technology Comparison, 2024). Comparing it with FDM 3D printer parts, SLA 3D printer parts are almost identical to injection-moulded polymers. Their exceptional surface smoothness makes them perfect for final design review prototypes and end-use products—even in the consumer goods sector, where smoothness and surface finish are critical. This level of smoothness strengthens SLA’s appeal for industries priortizing aesthetic and functional precision.

In contrast, one downside of parts printed by the SLA printers is that they tend to be vulnerable to corrosion. As these 3D printed parts are frequently in environments with corrosive chemicals present and will thus erode the parts and lose its quality. To counter this problem, industries will use a procedure called plating to achieve corrosion resistance and shield it from the corrosive environment. Plating is achieved by using a plating bath and depositing metal onto the 3D-printed part. This is an additional requirement to attain corrosion resistance, adding time and expenses to the manufacturing process (Kushwaha et al., 2022).

To conclude, Stereolithography (SLA)’s ability to produce parts with exceptional resolution, precision and surface finish underscores its value as a leading 3D printing technology for Rapid Prototyping and beyond. It makes it superior to other methods such as the Fused Deposition Modelling (FDM) in many aspects. Despite the higher costs and need for additional post-processing steps, the durability of SLA printed parts enhances their marketability and application in various industries. However, its printed parts face challenges such as material limitations and vulnerability to corrosion. Overall, SLA’s advantages in producing detailed and robust prototypes outweigh its higher costs and therefore provide a high cost-benefit ratio. This makes SLA an indispensable tool in various industries demanding precision and quality.

 

Edited 29/11/2024

  

References

 

Formlabs. (2015). Guide to stereolithography (SLA) 3D printing. Formlabs. https://formlabs.com/asia/blog/ultimate-guide-to-stereolithography-sla-3d-printing/

 

Gardan, J. (2015). Additive manufacturing technologies: State of the art and trends. International Journal of Production Research, 54(10), 3118–3132. https://doi.org/10.1080/00207543.2015.1115909

 

Robles Martinez, P., Basit, A. W., & Gaisford, S. (2018). The history, developments, and opportunities of stereolithography. In A. Basit & S. Gaisford (Eds.), 3D printing of pharmaceuticals: AAPS advances in the pharmaceutical sciences series (Vol. 31, pp. 1–26). Springer. https://doi.org/10.1007/978-3-319-90755-0_4

 

Kushwaha, A. K., Rahman, M. H., Hart, D., Hughes, B., Saldana, D. A., Zollars, C., Rajak, D. K., & Menezes, P. L. (2022). Fundamentals of stereolithography: Techniques, properties, and applications. In Tribology of additively manufactured materials (pp. 87–106). Elsevier. https://doi.org/10.1016/b978-0-12-821328-5.00003-2

 

Formlabs. (2024). FDM vs. SLA vs. SLS: 3D printing technology comparison. Formlabs. https://formlabs.com/asia/blog/fdm-vs-sla-vs-sls-how-to-choose-the-right-3d-printing-technology/

 

Markforged. (2024). FDM vs SLA - 3D printing process breakdown. Markforged. https://markforged.com/resources/blog/fdm-vs-sla

 

Hague, R., Mansour, S., Saleh, N., & Harris, R. (2004). Materials analysis of stereolithography resins for use in rapid manufacturing. Journal of Materials Science, 39(7), 2457–2464. https://doi.org/10.1023/b:jmsc.0000020010.73768.4a

 

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