Additive Manufacturing Strategies

3D Printing in Indonesia: Researching PLA Infill Pattern & Density

ST Medical Devices

Share this Article

In the recently published ‘Infill pattern and density effects on the tensile properties of 3D printed PLA material,’ researchers from Indonesia delve further into the details of fabrication with polylactic acid (PLA) material, working with three different infill densities and patterns.

While both acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) are commonly used in 3D printing, for this study the researchers focused on PLA—often chosen due to affordability, accessibility, and potential for producing innovative, lightweight prototypes and parts. Not only that, because of its plant-based nature, PLA is biodegradable and more environmentally friendly.

Mainly investigating infill density and infill pattern, the research team used tensile tests to reveal material properties, varying parameters to test properties such as tensile strength, yield strength, and ultimate strength.

The following infill densities were chosen:

  • 25 percent
  • 50 percent
  • 75 percent

Three infill patterns were used:

  • Grid
  • Tri-hexagon
  • Concentric

Five samples were used per each combination, resulting in 45 specimens overall. The researchers used 1.75mm PLA, printing melting temperatures of approximately 190°C – 230°C. For 3D printing specimens, the research team used a temperature setting of 210°C.

The dimension of ASTM D638 – type I test specimen in mm

Infill patterns were printed as follows:

  • Grid pattern printing object layers in 90-degree crossing paths
  • Tri-hexagonal patterns printing object layers in three path directions, each varying by 120 degrees of the other
  • Lowest path angle (in terms of specimen axial axis) of 30 degrees
  • Concentric pattern printing in direction of specimen axial axis

Infill patterns: (a) grid, (b) tri-hexagonal, and (c) concentric. Grid pattern infill densities: (d) 25%, (e) 50%, and (f) 75%

Tensile properties of the PLA Specimens

Overall, the study showed that as tensile properties increase, the infill density increases—with the exclusion of the concentric pattern at 75 percent infill density.

Stress-strain plots: (a) grid pattern with varied infill densities, (b) 50% infill density with varied infill patterns.

“Based on the result, the highest tensile properties corresponded to concentric pattern with 75% of infill density, where it has 42.2 MPa of ultimate strength, 3.89 GPa of Young’s modulus, and 40.98 MPa of yield strength. In addition, grid pattern with 100% infill density was tested and it was recorded that the Young’s modulus and yield strength were 3.6 GPa and 48.2 MPa, respectively. For 100% infill density, the effect of infill pattern on mechanical properties is negligible,” concluded the researchers.

“The results can be used as reference data for creating finite element model (FEM) and predicting the optimum tensile properties with respect to the selection of the printing parameters. Comprehensive investigation on the effect of infill pattern on the tensile properties is suggested for future study.”

Research continues regarding PLA, from experimenting with composite materials in medical applications to the influence of color, additives like antioxidants, and more.

What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘Infill pattern and density effects on the tensile properties of 3D printed PLA material’]

Share this Article


Recent News

3D Printing Robots Receive €1 Million Boost

3D Printing People: A Dialogue Beyond Industry at TIPE 2022



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

3D Printing Webinar and Event Roundup: January 16, 2022

We’re back in business this week with plenty of webinars and events, both virtual and in-person, starting with the second edition of the all-female-speaker TIPE 3D Printing conference. There are...

Women in 3D Printing’s Posts Agenda for TIPE Conference and Virtual Career Fair

This January 18-20, Women in 3D Printing (Wi3DP) is back for the second time in a row with its TIPE 3D Printing Conference and Virtual Career Fair. Like its inaugural...

Women in 3D Printing Onboards New President

As the nonprofit celebrates seven years of supporting women in the additive manufacturing (AM) industry, Women in 3D Printing (Wi3DP) has taken on a new leader. Kristin Mulherin is taking...

3D Printing Trade Show Best Practices: Food and Food for Thought

This is the third installment of ideas, suggestions, and best practices for your 3D printing stand from an interested observer. We previously discussed booth location and how best to connect...


Shop

View our broad assortment of in house and third party products.