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http://dx.doi.org/10.7736/KSPE.2013.30.12.1295

The Improvement of Weldline and Flow mark Defection by using Injection Molding Analysis  

Lee, Yeong Chang (Yeungjin Colloge)
Publication Information
Journal of the Korean Society for Precision Engineering / v.30, no.12, 2013 , pp. 1295-1301 More about this Journal
Abstract
The cause of flow mark defect is known as non-uniform temperature of mold surface when the flow front meets the cold cavity. The exact definition and classification of Flow mark is not clear because the mechanism of flow mark is not figured out till now. Any injection molding analysis software can not predict the flow mark phenomena. To solve weldline and flow mark defects, the gate thickness is reduced to increase the melt front velocity and the melt front velocity of the flow mark area is increased from 82.3mm/s to 104.7mm/s. In addition, the bulk temperature of the flow mark area is increased from $178.3^{\circ}C$to $215.2^{\circ}C$ by adding a cold slug well. The flow mark phenomena can be greatly reduced by increasing the flow front velocity and elevating the bulk temperature.
Keywords
Computer Aided Engineering (CAE); Injection Molding Analysis; Flow mark; Weldline; Melt Front Velocity (MFV);
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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1 Hobbs, S. Y., "The Development of Flow Instabilities during the Injection Molding of Multi-component Resins," Polym. Eng. Sci., Vol. 36, No. 11, pp. 1489- 1494, 1996.   DOI   ScienceOn
2 Hamada, H. and Tsunasawa, H., "Correlation between flow mark and internal structure of thin PC/ABS blend injection moldings," Journal of Applied Polymer Science, Vol. 60, No. 3, pp. 353-362, 1996.   DOI
3 Bulters, M. and Schepens, A., "The Origin of the Surface Defect 'Slip-Stick' on Injection Molded Products," Proc. of the 16th Annual Meeting of the Polymer Processing Society, pp. 144-145, 2000.
4 Chang, M. C. O., "On the Study of Surface Defects in the Injection Molding of Rubber-modified Thermoplastics," ANTEC '94, pp. 360-367, 1994.
5 Monasse, B., Vincent, M., Haudin, J. M., Gazonnet, J. P., Durand. V., and et al., "Flow marks in Injection Molding of Polypropylene : Influence of Processing Conditions and Formation in Fountain Flow," Proc, of the 15th Annual Meeting of the Polymer Processing Society, s'Hertogenbosch, 1999.
6 Grillet, A. M., Bogaerds, A. C. B., Peters, G. W. M., Baaijens, F. P. T., and Bulters, M., "Numerical analysis of flow mark surface defects in injection molding flow," Journal of Rheology (1978-present), Vol. 46, No. 3, pp. 651-669, 2002.   DOI   ScienceOn
7 SIMPOE SAS, "SIMPOE Theoretical Manual," 2012.
8 Alves, M. A., Pinho, F. T., and Oliveira, P. J., "Study of steady pipe and channel flows of a single-mode Phan-Thien-Tanner fluid," Journal of Non- Newtonian Fluid Mechanics, Vol. 101, No. 1-3, pp. 55-76, 2001.   DOI   ScienceOn
9 Grillet, A. M., Bogaerds, A. C. B., Peters, G. W. M., and Baaijens, F. P. T., "Stability Analysis of Constitutive Equations for Polymer Melts in Viscometric Flows," Journal of Non-Newtonian Fluid Mechanics, Vol. 103, No. 2-3, pp. 221-250, 2002.   DOI   ScienceOn
10 Kamal, M. R., Chu, E., Lafleur, P. G., and Ryan, M. E., "Computer Simulation of Injection Mold Filling for Viscoelastic Melts with Fountain Flow," Polymer Engineering & Science, Vol. 26, No. 3, pp. 190-196, 1986.   DOI   ScienceOn
11 King, R. C., Apelian, M. R., Armstrong, R. C., and Brown, R. A., "Numerically Stable Finite Element Techniques for Viscoelastic Flow Calculations in Smooth and Singular Geometries," J. NonNewtonian Fluid Mech. Vol. 29, pp. 147-216, 1989.
12 Sato, T., and Richardson, S. M., "Numerical simulation of the fountain flow problem for viscoelastic fluids," Polymer Engineering & Science, Vol. 35, No. 10, pp. 805-812, 1995.   DOI   ScienceOn
13 Park, K., Sohn, D. -H., and Seo, Y. S., "Investigation of Weldline Strength with Various Heating Conditions," J. Korean Soc. Precis. Eng., Vol. 27, No. 1, pp. 105-112, 2010.   과학기술학회마을
14 Kwon, O. K., Yun, J. H., and Park, K., "Improvement of Moldability for Ultra Thin-Wall Molding with Micro-Patterns," Trans. Korean Soc. Mech. Eng. A., Vol. 31, No. 5, pp. 556-561, 2007.   과학기술학회마을   DOI   ScienceOn