This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Influence of Weld Lines on the Mechanical Properties of Talc Filled Polypropylene
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 14, 2020 by SAE International in United States
Annotation ability available
Weld lines can significantly reduce ultimate tensile strength (UTS) and fracture strain of talc filled polypropylene (PP). In this paper, two different injection molding tests were completed. First, an injection mold with triangular inserts was built to study the influence of meeting angles on material properties at the weld line region. Tensile samples were cut at different locations along the weld line on the injection molded plaques. The test results showed that both UTS and fracture strain increase when the sample locations are away from the insert. This trend is attributed to different meeting angles. Second, standard ISO tensile bars with and without weld line were injection molded to identify the size of the weld line affected zone. A FEA model was built in ABAQUS, where the tensile sample was divided into two different regions, the solid region and the weld line affected region. Stress-strain relationships of the solid region were derived from tensile tests of solid bars, while the mechanical properties of weld line affected zones were characterized from the weld line samples using Digital Image Correlation (DIC) analysis. By changing the width of the weld line affected zone in the FEA model, and comparing the predictions with experiment data, it is possible to find out the approximate width of the weld line affected zone.
CitationHuang, S., Tibbenham, P., Su, L., Zeng, D. et al., "Influence of Weld Lines on the Mechanical Properties of Talc Filled Polypropylene," SAE Technical Paper 2020-01-1306, 2020, https://doi.org/10.4271/2020-01-1306.
- Kuehnert, I., Spoerer, Y., and Zimmermann, M. , “Weld Lines in Injection Molded Parts: Strength, Morphology and Improvement,” Annual Technical Conference - ANTEC, Conference Proceedings, 0:1255-1259, 2016.
- Sun, X., Huang, S., Tibbenham, P. et al. , “Study of Weld Line Strength Factors of Injection Molded Plastics,” Ford Technical Report, SRR-2018-0158.
- Malguarnera, S.C. and Manisali, A. , “The Effects of Processing Parameters on the Tensile Properties of Weld Lines in Injection Molded Thermoplastics,” Polymer Engineering and Science 21(10):586-593, 2004.
- Selden, R. , “Effect of Processing on Weld Line Strength in Five Thermoplastics,” Polymer Engineering and Science 37(1):205-218, 1997.
- Wu, C. and Liang, W. , “Effects of Geometry and Injection Molding Parameters on Weld Line Strength,” Polymer Engineering and Science 45(7):1021-1030, 2005.
- Onken, J. and Hopmann, C. , “Prediction of Weld Line Strength in Injection-Moulded Parts Made of Unreinforced Amorphous Thermoplastics,” International Polymer Science and Technology 43(11):T1-T8, 2016.
- Chuntai, L. and Changyu, S. , “The influence of Meeting Angle on the Weld Line Strength in Injection Molded Short-Fiber-Reinforced Polyamide 66,” Annual Technical Conference - ANTEC, Conference Proceedings 3:39-43, 2005.
- Sun, X., Tibbenham, P., Zhou, J., Zeng, D. et al. , “Weld Line Factors for Thermoplastics,” SAE Technical Paper 2017-01-0481, 2017, https://doi.org/10.4271/2017-01-0481.
- ISO 527-1:2019 , “Plastics - Determination of Tensile Properties - Part 1: General Principles.”