Enhancement of Mechanical and Thermal Properties of Injection-Molded Polypropylene Parts Using Glass Fibers

Document Type : Original Article

Authors
Mohammad Reza Ebrahimian 1
Farzad Rahmani 1
Hamed hajnasiri 2
1 Assistant Professor, Department of Mechanical Engineering, Kar Higher Education Institute, Qazvin, Iran
2 M.Sc. Student, Department of Mechanical Engineering, Kar Higher Education Institute, Qazvin, Iran
10.22034/stme.2025.532480.1141
Abstract
This study investigated the improvement of mechanical and thermal properties in polypropylene matrix composites by adding glass fiber reinforcement. The results showed significant outputs in several tests. The addition of reinforcing particles resulted in a decrease in yield strain, while causing significant changes in yield strength. Charpy impact tests showed different energy absorption. This study investigated the effect of adding glass fibers with different L/D ratios (250, 300, 350) on the mechanical and thermal properties of injection molded polypropylene composites. The samples were produced by twin-screw extrusion and injection molding and tested according to ISO and ASTM standards. The results showed that the sample with 30% glass fibers (L/D=350) had the highest yield strength (98.6 MPa), impact energy absorption (14.1 kJ/m²), and thermal deflection temperature (151.7°C), and the shrinkage was reduced to 0.26%. These results indicate the potential of these composites for engineering applications with high dimensional accuracy. In addition, the addition of glass fibers resulted in a decrease in the melt flow index, while other particles showed the least effect.
Keywords
Polymer composites
Reinforced polypropylene
Mechanical properties
Composite additives
Glass fibers
Subjects
[1] K. Rahmani, A. Nouri, H. Bakhtiari, A. Sadooghi, A. Ghofrani, M. P. Nikolova, and F. Salmani, "Mechanical and corrosion properties of Mg–MgO and Mg–Al₂O₃ composites fabricated by equal channel angular extrusion method", Smart Materials in Manufacturing, Vol. 1, p. 100010, 2023. doi: 10.1016/j.smmf.2022.100010
[2] S. J. Hashemi, A. Sadooghi, K. Rahmani, and S. Nokhbehroosta, "Experimental determining the mechanical and stiffness properties of natural rubber FRT triangle elastic joint composite reinforcement by glass fibers and micro/nano particles", Polymer Testing, Vol. 85, p. 106461, 2020. doi: 10.1016/j.polymertesting.2020.106461
[3] K. Baek, H. Kim, H. Shin, H. Park, and M. Cho, "Multiscale study to investigate nanoparticle agglomeration effect on electrical conductivity of nano-SiC reinforced polypropylene matrix composites", Mechanics of Advanced Materials and Structures, Vol. 30, No. 12, pp. 2442–2452, 2023. doi: 10.1080/15376494.2022.2054037
[4] C. E. Njoku, J. A. Omotoyinbo, K. K. Alaneme, and M. O. Daramola, "Structural characterization and mechanical behaviour of sodium hydroxide-treated urena lobata fiber reinforced polypropylene matrix composites", Fibers and Polymers, Vol. 21, pp. 2983–2992, 2020. doi: 10.1007/s12221-020-1289-3
[5] A. Kościuszko, P. Czyżewski, Ł. Wajer, A. Ościak, and M. Bieliński, "Properties of polypropylene composites filled with microsilica waste", Polimery, Vol. 65, No. 2, pp. 99–104, 2020.
[6] S. Begum, S. Fawzia, and M. Hashmi, "Polymer matrix composite with natural and synthetic fibres", Advances in Materials and Processing Technologies, Vol. 6, No. 3, pp. 547–564, 2020. doi: 10.1080/2374068X.2020.1728645
[7] A. Ari, A. Bayram, M. Karahan, and S. Karagöz, "Comparison of the mechanical properties of chopped glass, carbon, and aramid fiber reinforced polypropylene", Polymers and Polymer Composites, Vol. 30, p. 09673911221098570, 2022. doi: 10.1177/09673911221098570
[8] K. Hariprasad, K. Ravichandran, V. Jayaseelan, and T. Muthuramalingam, "Acoustic and mechanical characterisation of polypropylene composites reinforced by natural fibres for automotive applications", Journal of Materials Research and Technology, Vol. 9, No. 6, pp. 14029–14035, 2020. doi: 10.1016/j.jmrt.2020.09.112
[9] J. Korol, A. Hejna, D. Burchart-Korol, and J. Wachowicz, "Comparative analysis of carbon, ecological, and water footprints of polypropylene-based composites filled with cotton, jute and kenaf fibers", Materials, Vol. 13, No. 16, p. 3541, 2020. doi: 10.3390/ma13163541
[10] K.-W. Kim, W. Han, and B.-J. Kim, "Effects of mixing ratio of hybrid carbonaceous fillers on thermal conductivity and mechanical properties of polypropylene matrix composites", Polymers, Vol. 14, No. 10, p. 1935, 2022. doi: 10.3390/polym14101935
[11] S. Brahma, S. M. Raafi, S. N. Arju, and J. U. Rehman, "Dyeability and mechanical properties of banana fiber reinforced polypropylene composite", SPE Polymers, Vol. 5, No. 3, pp. 353–365, 2024. doi: 10.1002/pls2.10129
[12] K. R. Sumesh, A. Ajithram, K. S. Anjumol, and G. Sai Krishnan, "Influence of natural fiber addition and fiber length in determining the wear resistance of epoxy-based composites", Polymer Composites, Vol. 45, No. 4, pp. 3029–3042, 2024. doi: 10.1002/pc.27968
[13] H. Soleymani, A. Fereidoon, A. Albooyeh, and M. Nakhaee, "Optimization of mechanical and morphological properties of polypropylene reinforced with natural rubber-perlite nanoparticles using response surface method", Metallurgical and Materials Engineering, Vol. 34, No. 30, pp. 1–18, 2023. doi: 10.22067/JMME.2023.80165.1092
[14] M. Shoa, P. Shahi, S. K. Hedayati, and M. R. Ebrahimian, "Experimental investigation on mechanical properties of wood plastic hybrid campsites based on polyethylene/polyamide and reinforced with carbon fibers", Mechanical Engineering University of Tabriz, Vol. 52, No. 3, pp. 135–143, 2022. doi: 10.22034/JMEUT.2022.48574.3003
 
 
‏

  • Receive Date 03 July 2025
  • Revise Date 26 July 2025
  • Accept Date 14 September 2025
  • First Publish Date 14 September 2025
  • Publish Date 23 July 2026

Article View 2,686