This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Weld Line Factors for Thermoplastics
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 28, 2017 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. It is important to investigate the weld line because the weld line area can induce potential failure of structural application. In this paper, a weld line factor (W-L factor) was adopted to describe the strength reduction to the ultimate strength due to the appearance of weld line. There were two engineering thermoplastics involved in this study, including one neat PP and one of talc filled PP plastics. The experimental design was used to investigate four main injection molding parameters (melt temperature, mold temperature, injection speed and packing pressure). Both the tensile bar samples with/without weld lines were molded at each process settings. The sample strength was obtained by the tensile tests under two levels of testing speed (5mm/min and 200mm/min) and testing temperatures (room temperature and -30°C). The results showed that different materials had various values of W-L factor. For neat PP, the W-L factor was high and independent to injection molding parameters or testing temperatures. For the talc filled PP, the W-L factor reduced significantly and was not sensitive to the injection molding parameters or testing speed. The talc particles played dominant role in reducing the W-L factor. The influence of packing pressure could be ignored.
CitationSun, 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.
Data Sets - Support Documents
|Unnamed Dataset 1|
|Unnamed Dataset 2|
- Chen , M. , Tzeng , H. , Chen , Y. and Chen S. The application of fuzzy theory for the control of weld line positions injection-molded part ISA Transactions 47 1 119 126 2008
- 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
- Li , H. , Guo , Z. and Li , D. Reducing the effects of weld lines on appearance of plastic products by Taguchi experimental method International Journal of Advanced Manufacturing Technology 32 9 927 931 2007
- Yamada , K. , Tomari , K. , Ishiaku , U.S. and Hamada , H. Evaluation of Mechanical Properties of Adjacent Flow Weld line Polymer Engineering and Science 45 8 1180 1186 2005
- Chen , S. , Chang , Y. , Chang , Y. , Chen , Y. and Tseng , C. Effect of cavity surface coating on mold temperature variation and the quality of injection molded parts International Communications in Heat and Mass Transfer 36 10 1030 1035 2009
- Ozcelik , B. Optimization of injection parameters for mechanical properties of specimens with weld line of polypropylene using Taguchi method International Communications in Heat and Mass Transfer 38 8 1067 1072 2011
- Ozcelik , B. , Kuram , E. and Topal , M. M. Investigation the effects of obstacle geometries and injection molding parameters on weld line strength using experimental and finite element methods in plastic injection molding Communications in Heat and Mass Transfer 39 2 275 281 2012
- Kim , S. and Suh , P. N. Performance prediction of weldline structure in amorphous polymers Polymer Engineering and Science 26 17 1200 1207 1986
- Mekhilef , N. , Ait-Kadi , A. and Ajji , A. Weld lines in injection-moulded immiscible blends: model predictions and experimental results Polymer 36 10 2033 2042 1995
- Zhou , Y. and Mallick , P. K. Effect of Melt Temperature and Hold Pressure on the Weld-Line Strength of an Injection Molded Talc-Filled Polypropylene Journal of Composites 2014 8 http://dx.doi.org/10.1155/2014/846962