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. 2022 Apr 13;14(8):1577.
doi: 10.3390/polym14081577.

Innovative Injection Molding Process for the Fabrication of Woven Fabric Reinforced Thermoplastic Composites

Euichul Jeong  1   2 , Yongdae Kim  2 , Seokkwan Hong  2 , Kyunghwan Yoon  1 , Sunghee Lee  2
Affiliations

Innovative Injection Molding Process for the Fabrication of Woven Fabric Reinforced Thermoplastic Composites

Euichul Jeong et al. Polymers (Basel). .

Abstract

Woven fabric reinforced thermoplastic composites have been gaining significant attention as a lightweight alternative to metal in various industrial fields owing to their high stiffness and strength. Conventional manufacturing processes of woven fabric reinforced thermoplastic composites can be divided into two steps: first, the manufacturing of intermediate material, known as prepreg; then, the formation of the final products from the prepregs. This two-step process increases the manufacturing cost and time of the final composite products. This study demonstrated that woven fabric reinforced thermoplastic composites could be fabricated by an innovative injection molding process instead of the two-step process. A structure placing an extra mesh, which is a new and key component, on the mold-side of woven fabric was devised so that the thermoplastic matrix could be impregnated up to the surface of the woven fabric during injection molding. Tensile tests were performed in the direction parallel to the yarns of the fabric on the injection-molded composites to confirm their mechanical properties. As a result, it was possible to fabricate woven fabric reinforced thermoplastic composites with increased mechanical properties using injection molding without prepreg, and the composites could be molded with a much shorter cycle time than the conventional process, such as thermoforming or over-molding process.

Keywords: composite; injection molding; mesh; reinforced thermoplastic; woven fabric.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Classification of fiber-reinforced polymer composites.
Figure 2
Figure 2
Comparison of woven fabric reinforced thermoplastic composites molding process: (a) press thermoforming; (b) prepreg injection over-molding; (c) mesh-inserted injection molding.
Figure 3
Figure 3
Schematics of the top view, cross-section view, and simplified symbol: (a) woven fabric; (b) mesh.
Figure 4
Figure 4
Images of the woven fabric and mesh: (a) fabric A (1k); (b) fabric B (3k); (c) mesh.
Figure 5
Figure 5
Photographs of the (a) injection molding machine and (b) mold used.
Figure 6
Figure 6
Schematics of the impregnation experiment and SEM images on the surface of cavity side for injection-molded composites: (a) placing only the woven fabrics; (b) placing meshes between the woven fabric and mold surface.
Figure 7
Figure 7
Schematics of the insert structures: (a) 2-MF structure; (b) 4-MF structure; (c) mold insert structure.
Figure 8
Figure 8
Optical microscopy images of the cross-section of the molded composites: (a) 2-MF (1k); (b) 4-MF (1k); (c) 2-MF (3k); (d) 4-MF (3k).
Figure 9
Figure 9
SEM images of the 4-MF (3k) composites: (a) cross-section of warp; (b) cross-section of weft.
Figure 10
Figure 10
Results of the tensile tests of mesh-inserted composites: (a) direction of loading; (b) cross-section images of composites; (c) stress–strain curves of composites and virgin matrix.
See this image and copyright information in PMC

References

    1. Rezaei F., Yunus R., Ibrahim N.A., Mahdi E.S. Development of short carbon fiber reinforced polypropylene composite for car bonnet. Polym.-Plast. Technol. Eng. 2008;47:351–357. doi: 10.1080/03602550801897323. - DOI
    1. Unterweger C., Bruggemann O., Furst C. Synthetic fibers and thermoplastic short fiber reinforced polymers: Properties and characterization. Polym. Compos. 2014;35:227–236. doi: 10.1002/pc.22654. - DOI
    1. Yi S. Multifunctionality of Polymer Composites. William Andrew Publishing; Oxford, UK: 2015. Development of multifunctional composites for aerospace application; pp. 367–418.
    1. Holmes M. High volume composites for automotive challenge. Reinf. Plast. 2017;61:294–298. doi: 10.1016/j.repl.2017.03.005. - DOI
    1. Kusic D., Bozic U., Monzon M., Bordon P. Thermal and mechanical characterization of banana fiber reinforced composites for its application in injection molding. Materials. 2020;13:3581. doi: 10.3390/ma13163581. - DOI - PMC - PubMed

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