Abstract
Tensile and flexural properties of single-gated (SG) and double-gated (DG) injection moulded blend of polybutylene terephthalate (PBT) and polycarbonate (PC) and its composites containing 15, 20 and 30 wt.% short glass fibres were investigated. In the DG mouldings, a weldline was formed by direct impingement of two opposing melt fronts (i.e. cold weld). It was found that tensile modulus was not affected by the weldline but flexural modulus decreased in the presence of weldline. For both specimen types, modulus increased linearly with volume fraction of fibres (ϕf), according to the rule-of-mixtures for moduli. The weldline integrity (WIF) factor for flexural modulus decreased linearly with increasing ϕf. Results showed that tensile and flexural strengths for SG mouldings increase with increasing ϕf in a linear manner according to the “rule-of-mixtures” for strengths. The presence of weldline affected both strengths in a significant way; WIF factor decreased linearly with increasing ϕf and was independent of loading mode. It was noted also, that the overall fibre efficiency parameter for tensile modulus was independent of specimen type but for flexural modulus it was lower in the case of DG mouldings. In all cases, efficiency parameter for strength was considerably lower than for the modulus. Impact strength and fracture toughness of SG mouldings were significantly greater than for DG mouldings. Although these properties for SG mouldings increased with increasing ϕf, they decreased significantly for DG mouldings. Results showed that WIF factor for impact strength and fracture toughness decreased linearly with increasing ϕf.
Similar content being viewed by others
References
Hashemi S, Gilbride MT, Hodgkinson JM (1996) J Mater Sci 31:5017. doi:https://doi.org/10.1007/BF00355900
Din KJ, Hashemi S (1997) J Mater Sci 32:375. doi:https://doi.org/10.1023/A:1018553400266
Chrysostomou A, Hashemi S (1998) J Mater Sci 33:1165. doi:https://doi.org/10.1023/A:1004365323620
Chrysostomou A, Hashemi S (1998) J Mater Sci 33:4491. doi:https://doi.org/10.1023/A:1004487814709
Nabi ZU, Hashemi S (1998) J Mater Sci 33:2985. doi:https://doi.org/10.1023/A:1004362915713
Hashemi S (2002) J Plast Rubber Compos 31:1. doi:https://doi.org/10.1179/146580101125000484
Hashemi S, Lepessova Y (2007) J Mater Sci 42:2652. doi:https://doi.org/10.1007/s10853-006-1358-z
Necar M, Irfan-ul-Haq M, Khan Z (2003) J Mater Process Technol 142:247. doi:https://doi.org/10.1016/S0924-0136(03)00567-3
Fu SY, Lauke B, Mader E, Yue CY, Hu X (2000) Composites A 31:1117
Fisa B (1985) Polym Compos 6:232. doi:https://doi.org/10.1002/pc.750060408
Thomason JL (2002) Compos Sci Technol 62:1455. doi:https://doi.org/10.1016/S0266-3538(02)00097-0
Thomason JL (2001) Compos Sci Technol 61:2007. doi:https://doi.org/10.1016/S0266-3538(01)00062-8
Cox HL (1952) Br J Appl Phys 3:72. doi:https://doi.org/10.1088/0508-3443/3/3/302
Krenchel H (1964) Fibre reinforcement. Akademisk Forlag, Copenhagen
Courtney TH (1990) Mechanical behaviour of materials. McGraw-Hill International Editions
Kelly A, Tyson WR (1965) J Mech Phys Solids 13:329. doi:https://doi.org/10.1016/0022-5096(65)90035-9
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Khamsehnezhad, A., Hashemi, S. Mechanical properties of single- and double-gated injection moulded short glass fibre reinforced PBT/PC composites. J Mater Sci 43, 6344–6352 (2008). https://doi.org/10.1007/s10853-008-2918-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-008-2918-1