Optimization of Process Parameters in 3D Printing for Validation of Mechanical Properties in End Product

Abstract

This study presents a systematic methodology for optimizing process parameters in Fused Deposition Modelling (FDM), a widely used additive manufacturing method, to validate the mechanical feasibility of end-use parts printed from Polylactic Acid (PLA). The core objective is to overcome the common limitation of 3D printed prototypes by demonstrating that printed components can achieve mechanical performance comparable to conventionally produced parts. The research focuses on three key process parameters: infill pattern (Line, Grid, Honeycomb), infill density (50%, 75%, 100%), and raster angle (0°, 45°, 90°), which significantly influence structural integrity, load distribution, layer bonding, and overall durability. An extensive experimental design was formulated, involving the fabrication of standard test specimens (tensile, flexural, Charpy impact) conforming to ASTM D638, D790, and D256 specifications. Two specimens were fabricated per parameter combination to enhance statistical reliability, undergoing mechanical testing to assess tensile strength, flexural modulus, and impact resistance. Data analysis was performed using a Taguchi L9 orthogonal array, an efficient statistical design of experiments (DOE) technique, to identify the most significant parameters and their optimal levels for improved mechanical properties. The optimized parameters were then applied to manufacture an easily accessible consumer item, which was subsequently tested to ensure repeatability and functional applicability. The results confirm that PLA, processed under optimized FDM conditions, provides repeatable and adequate mechanical properties for actual use, reinforcing 3D printing\'s potential as a cost-effective, customizable, and sustainable manufacturing solution for functional components.

Introduction

Background

• Additive Manufacturing (AM), or 3D printing, builds objects layer by layer from digital models, offering significant design flexibility and minimal material waste.

• Originally used for rapid prototyping, AM has expanded into sectors like aerospace, healthcare, automotive, and architecture.

• Fused Deposition Modelling (FDM) is a popular AM method, especially using PLA, a biodegradable thermoplastic.

Problem Statement

• FDM-printed PLA parts often suffer from inconsistent mechanical properties, limiting their use in functional or load-bearing applications.

• These inconsistencies are influenced by various printing parameters, which are not yet standardized or fully optimized.

Research Objectives

1. Evaluate the impact of:

   • Infill pattern (Line, Grid, Honeycomb)

   • Infill density (50%, 75%, 100%)

   • Raster angle (0°, 45°, 90°)

2. Improve mechanical properties such as tensile, flexural, and impact strength.

3. Prove that FDM-printed PLA parts can be suitable for daily-use and functional applications.

4. Use the Taguchi L9 orthogonal array to identify optimal parameter combinations.

Historical Context of AM

• 3D printing started in the 1980s with Stereolithography (SLA) by Charles Hull.

• The 1990s saw the introduction of FDM (Stratasys) and SLS.

• In the 2000s, bioprinting and open-source RepRap broadened public access.

• The 2010s and 2020s saw integration with Industry 4.0, AI, and applications in construction, medical, and food industries.

Methodology

• Material Used: PLA

• Printing Method: FDM, using consistent temperatures (Nozzle: 210°C, Bed: 60°C)

• Experimental Design:

  • ASTM-standard specimens for tensile, flexural, and impact testing

  • Taguchi L9 array used to test 3 parameters with 3 levels (9 combinations)

  • Prusa Slicer software for slicing and STL preparation

Mechanical Testing Standards

• Tensile Testing: ASTM D638 (“dog-bone” samples)

• Flexural Testing: ASTM D790 (3-point bending)

• Impact Testing: ASTM D256 (Charpy notched bar)

Key Analysis

• ANOVA (Analysis of Variance) was used to analyze the effects of each parameter.

• Identified optimal combinations of infill pattern, density, and raster angle for enhanced strength and reliability.

• Validated results by applying optimal settings to real-life products (e.g., mixer grinder coupler, IR sensor housing).

Applications & Benefits

• Customized, low-cost solutions for broken parts and home repairs

• Enables functional, ergonomic, and space-saving tools

• Bridges the gap between prototypes and functional end-use components

Conclusion

This study marks a significant step in transforming 3D printing from an empirical practice to a science-based process by optimizing key parameters such as infill pattern, infill density, and raster angle for FDM-printed PLA components. Using a systematic experimental design (Taguchi L9 orthogonal array) and ASTM-standard mechanical testing, it identified the optimal combinations that enhance tensile, flexural, and impact strengths. The successful production and validation of real-world parts like an IR sensor housing and mixer-grinder coupler demonstrated the practical reliability and repeatability of these settings. The research highlights FDM 3D printing with PLA as a cost-effective, customizable, and sustainable solution for producing functional components with dependable mechanical integrity for demanding applications.

References

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Copyright

Copyright © 2025 Varun Kulkarni , Ambika Roysulakhe, Nilam Hode, Ketaki Khatpe, Sandeep Raut. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.