On the Relationship between Mechanical Properties and Crystallisation of Chemically Post-Processed Additive...

Area of Science:

• Materials Science
• Polymer Engineering
• Additive Manufacturing

Background:

• Surface finish improvement is crucial for parts made by fused deposition modelling (FDM).
• Chemical post-treatments offer efficient surface smoothing but can impact material properties.
• Understanding the trade-offs between surface finish and mechanical integrity is essential.

Purpose of the Study:

• To investigate the effects of various chemical post-treatments on the mechanical properties of polylactic acid (PLA) parts.
• To correlate changes in crystallisation percentage with treatment parameters (type and immersion time).
• To quantify the impact of these treatments on tensile strength and hardness.

Main Methods:

• Polylactic acid (PLA) samples were subjected to different chemical post-treatments.
• Crystallisation percentage was analyzed in relation to treatment conditions and immersion duration.
• Mechanical testing was performed to measure tensile strength and hardness (Shore D and A scales).

Main Results:

• Significant alterations in mechanical properties were observed across different treatments.
• Maximum stress varied from 55 MPa to 20 MPa.
• Elongation at break increased dramatically from 3% to 260%.
• Hardness shifted from Shore D to Shore A scale.

Conclusions:

• Chemical post-treatments profoundly influence the mechanical behavior of FDM-printed PLA.
• The degree of crystallisation, modulated by treatment type and time, is a key factor in property modification.
• Careful selection of post-treatment is necessary to balance surface finish enhancement with desired mechanical performance.