Aziz Muhammad Mohid, Beard Logan, Ali Shafahat, Eltaggaz Abdelkrem, Deiab Ibrahim
Advanced Manufacturing Lab (AML), School of Engineering, University of Guelph, Guelph, ON N1G 2W1, Canada.
Mechanical Engineering Department, Australian University of Kuwait, Kuwait City 13015, Kuwait.
Polymers (Basel). 2025 Mar 22;17(7):852. doi: 10.3390/polym17070852.
Three-dimensional printing technology offers significant advantages in the production of orthopedic casts, providing a promising alternative to conventional plaster and fiberglass materials. Polylactic acid (PLA) is widely used for this purpose; however, its adoption is limited due to poor mechanical properties, including high brittleness, low thermal stability, and limited elongation. These challenges can be mitigated by blending PLA with other biodegradable polymers. This study investigated a blend of PLA with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a type of polyhydroxyalkanoate (PHA), and polycaprolactone (PCL) for the development of 3D printed orthopedic casts. The key mechanical properties-tensile strength, percent elongation at break, Young's modulus, flexural strength, flexural modulus, and impact strength-were evaluated as a function of the printing parameters, including nozzle temperature, layer height, and raster angle. The grey relational analysis (GRA) approach was applied to optimize these mechanical properties. The optimal printing parameters were found to be a nozzle temperature of 180 °C, a layer height of 0.18 mm, and a raster angle of 0°, resulting in a tensile strength of 44.4 ± 4.4 MPa, an elongation at break of 68.5 ± 11.6%, a Young's modulus of 948.7 ± 25.1 MPa, a flexural strength of 54.6 ± 8.9 MPa, a flexural modulus of 1549.3 ± 141 MPa, and an impact strength of 80.77 ± 5.6 J/m. Statistical analysis using analysis of variance (ANOVA) revealed that for tensile strength, 50.18% was influenced by the raster angle, 26.38% by the layer height, and 18.92% by the nozzle temperature; for flexural strength, 69.81% was influenced by the raster angle, 20.67% by the layer height, and 3.53% by the nozzle temperature; and for impact strength, 75.11% was influenced by the raster angle, 13.16% by the layer height, and 4.45% by the nozzle temperature.
三维打印技术在骨科石膏生产中具有显著优势，为传统石膏和玻璃纤维材料提供了一种有前景的替代方案。聚乳酸（PLA）广泛用于此目的；然而，由于其机械性能较差，包括高脆性、低热稳定性和有限的伸长率，其应用受到限制。通过将PLA与其他可生物降解聚合物共混可以缓解这些挑战。本研究调查了PLA与聚（3-羟基丁酸酯- co - 3-羟基戊酸酯）（PHBV）（一种聚羟基脂肪酸酯（PHA）类型）和聚己内酯（PCL）的共混物用于开发3D打印骨科石膏。关键机械性能——拉伸强度、断裂伸长率百分比、杨氏模量、弯曲强度、弯曲模量和冲击强度——作为打印参数的函数进行了评估，这些参数包括喷嘴温度、层高和光栅角度。应用灰色关联分析（GRA）方法来优化这些机械性能。发现最佳打印参数为喷嘴温度180°C、层高0.18 mm和光栅角度0°，拉伸强度为44.4±4.4 MPa，断裂伸长率为68.5±11.6%，杨氏模量为948.7±25.1 MPa，弯曲强度为54.6±8.9 MPa，弯曲模量为1549.3±141 MPa，冲击强度为80.77±5.6 J/m。使用方差分析（ANOVA）的统计分析表明，对于拉伸强度，50.18%受光栅角度影响，26.38%受层高影响，18.92%受喷嘴温度影响；对于弯曲强度，69.81%受光栅角度影响，20.67%受层高影响，3.53%受喷嘴温度影响；对于冲击强度，75.11%受光栅角度影响，13.16%受层高影响，4.45%受喷嘴温度影响。
