Quantifying residual orientation and thermal stress contributions to birefringence in the material extrusion of polylactide.

• Tác giả: Benjamin E Dolata, Yoontae Kim, Anthony P Kotula, Sara V Orski, Jonathan E Seppala
• Ngôn ngữ: eng
• Ký hiệu phân loại: 636.0885 Animal husbandry
• Thông tin xuất bản: Netherlands : Additive manufacturing , 2025
• Bộ sưu tập: NCBI
• ID: 212735

Tóm tắt

Material extrusion is a common additive manufacturing process that subjects polymers to non-steady deformation and thermal processing to build a customized part. The mechanical properties of these parts are often worse than those of injection-molded specimens due to failures at or near the weld zone between extrudate layers. Chain orientation is often cited as a contribution to mechanical weaknesss at the weld, and it is therefore of critical importance to develop strategies to quantify the magnitude and location of residual chain orientation as a function of printing conditions. Here we use birefringence imaging to characterize the spatial variation in residual stress and residual chain orientation in a glassy polylactide. A combination of retardance measurements and sample thickness measurements provide a measure of birefringence as a function of position. As-printed samples show a nearly uniform birefringence background of approximately 7 × 10