An Introduction to Extrusion-Based 3D Printing

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Introduction

Additive manufacturing (AM), commonly known as 3D printing, constructs objects layer-by-layer from digital models. This approach contrasts sharply with subtractive manufacturing, which creates parts by removing material from a solid block (Formlabs, n.d.). This blog provides a detailed look at additive manufacturing, specifically focusing on extrusion-based 3D printing, highlighting its advantages over traditional subtractive methods through industry examples.

Additive vs. Subtractive Manufacturing

Additive manufacturing is defined by ASTM as "the process of joining materials to make parts from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies" (Xometry, n.d.). Subtractive manufacturing involves cutting, drilling, or milling material away, resulting in substantial waste and limitations on complexity.

Key Differences:

  • Material Efficiency: Additive methods drastically reduce waste, with near-net-shape production significantly improving the "buy-to-fly" ratio (3DEO Inc., n.d.).
  • Design Freedom: AM supports highly complex designs, internal structures, and organic shapes that subtractive methods cannot feasibly produce.
  • Use Cases: AM excels in low-volume, customized, and highly complex products, whereas subtractive methods remain optimal for high-volume, precise, and simpler geometries (Formlabs, n.d.).

Extrusion-Based 3D Printing (Fused Deposition Modeling - FDM)

FDM is the most widely adopted additive manufacturing technology, characterized by the extrusion of thermoplastic filament through a heated nozzle to build objects layer-by-layer (Protolabs, n.d.).

How FDM Works:

  • Thermoplastic filament is melted and extruded through a nozzle.
  • The material solidifies upon deposition, forming successive layers.
  • Common materials include ABS, PLA, Nylon, PETG, and advanced polymers like PEEK (Protolabs, n.d.).

Advantages and Limitations:

  • Advantages: Cost-effectiveness, versatility, rapid prototyping, easy accessibility.
  • Limitations: Surface finish and resolution typically inferior to other AM techniques (e.g., SLA).

Industry Examples: AM Outperforming Subtractive Methods

Cost Efficiency

  • Rocket Engine Components: NASA and Aerojet Rocketdyne significantly reduced costs and lead times by 3D printing complex engine parts, achieving a 70% cost reduction and shorter production cycles (NASA News, n.d.).

  • GE Aviation: The LEAP engine’s fuel nozzle, produced via AM, reduced part count from 20 to 1, significantly decreasing weight and increasing durability (3D Printing Industry News, n.d.).

Mass Customization

  • Hearing Aids: Almost all custom hearing aids today are 3D printed, providing personalized fits quickly and economically (Sonova AG, n.d.; USITC, n.d.).
  • Dental Industry: Custom molds for orthodontic aligners and implants leverage 3D printing for tailored patient solutions.

Sustainability

  • AM dramatically reduces material waste from traditional machining processes, often from 95% to under 1% material waste, enhancing environmental sustainability (3DEO Inc., n.d.).

Speed and Responsiveness

  • AM enables rapid prototyping and on-demand production, significantly shortening product development cycles and lead times. An example includes NASA’s tool production aboard the ISS, showcasing immediate manufacturing capability (Formlabs, n.d.).

Conclusion

Extrusion-based 3D printing exemplifies the broader advantages of additive manufacturing, including cost savings, design flexibility, customization, reduced waste, and accelerated production. As AM technology matures, it continues to complement traditional subtractive methods, each fulfilling specific roles within modern manufacturing strategies.

Want to learn more?

Check out our other posts in this catagory, or purchase this book for a great starting point to 3d printing.

Book: "3D Printing Failures: 2022 Edition: How to Diagnose and Repair ALL Desktop 3D Printing Issues"- Sean Aranda https://a.co/d/7Q92VwW

References

Formlabs. (n.d.). Additive vs. Subtractive Manufacturing. https://formlabs.com/blog/additive-manufacturing-vs-subtractive-manufacturing/

Xometry. (n.d.). Subtractive Manufacturing vs. Additive Manufacturing. https://xometry.pro/en/articles/subtractive-additive-manufacturing/

3DEO Inc. (n.d.). Environmental Impact of Additive Manufacturing. https://www.3deo.co/metal-additive-manufacturing/environmental-impact-of-additive-manufacturing/

Protolabs. (n.d.). types of 3d printing https://www.protolabs.com/resources/blog/types-of-3d-printing/

NASA News. (n.d.). NASA, Industry Test Additively Manufactured Rocket Engine Injector. https://www.nasa.gov/news-release/nasa-industry-test-additively-manufactured-rocket-engine-injector/

3D Printing Industry News. (n.d.). GE’s 3D Printed LEAP Engine Nozzle. https://3dprintingindustry.com/news/ge-aviation-celebrates-30000th-3d-printed-fuel-nozzle-141165/

Sonova AG. (n.d.). 3D Printing Technology for Improved Hearing. https://www.sonova.com/en/story/innovation/3d-printing-technology-improved-hearing

USITC. (n.d.). How 3D Printing May Increase Trade in Hearing Aids. https://www.usitc.gov/publications/332/executive_briefings/ebot_downing_taylor_3d_printing_and_hearing_aids.pdf

Thank you for reading! - RH