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Influence of Raster Pattern on Residual Stress and Part Distortion in FDM of Semi-Crystalline Polymers: A Simulation
Anto Antony Samy1,2, Atefeh Golbang1,2, Eileen Harkin-Jones1
1Engineering Research Institute, Ulster University, Shore Road, Newtownabbey, Co., Antrim BT37 0QB, UK.
Polymers
|July 9, 2022
Summary
The study simulated fused deposition modeling (FDM) raster patterns in polypropylene, finding the concentric pattern significantly reduced warpage and residual stress. Other patterns like zigzag (45°/45°) increased both stress and distortion.
Area of Science:
- Materials Science and Engineering
- Additive Manufacturing
- Polymer Science
Background:
- Fused Deposition Modeling (FDM) is susceptible to internal thermal residual stresses.
- These stresses significantly impact mechanical properties and part distortion, especially in semi-crystalline polymers like polypropylene.
- Raster patterns used in FDM slicing software influence stress development and warpage.
Purpose of the Study:
- To simulate and analyze the effect of various FDM raster patterns on thermal residual stresses and warpage.
- To compare the performance of line (90°/90°), line (0°/90°), zigzag (45°/45°), zigzag (45°/-45°), and concentric patterns.
- To identify optimal raster patterns for minimizing distortion and stress in polypropylene FDM parts.
Main Methods:
- Simulation of the FDM process using Cura slicing software for polypropylene.
- Analysis of thermal residual stresses and warpage development over printing time and temperature.
- Comparison of five distinct raster patterns: line (90°/90°), line (0°/90°), zigzag (45°/45°), zigzag (45°/-45°), and concentric.
- Utilizing the line (90°/90°) pattern as a reference for relative comparisons.
Main Results:
- The concentric raster pattern resulted in the lowest warpage (5.5% decrease) and a significant reduction in residual stress (21%).
- The zigzag (45°/-45°) pattern showed the highest warpage increase (37%) with a 9.8% decrease in residual stress.
- The zigzag (45°/45°) pattern led to a 16.2% warpage increase and a 31% residual stress increase, while line (0°/90°) increased warpage by 24% and stress by 6.6%.
Conclusions:
- Raster pattern selection is critical for controlling residual stress and warpage in FDM of semi-crystalline polymers.
- The concentric pattern is highly effective in mitigating warpage and residual stress.
- Specific zigzag patterns can exacerbate warpage and stress, necessitating careful selection for optimal part quality in FDM applications.
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