2015

Cam Fiber Takviyeli Polimerlerin Plastik Enjeksiyonunda Fiber Yönlenmesinin İncelenmesi

Cam fiber takviyeli polimerlerin plastik enjeksiyonunda fiber yönlenmesinin kontrolü, malzemeninözelliklerini geliştirmek yönünden önem taşımaktadır. Fiberlerin polimerin akış yönüne paralel veyarastgele yönlenmesine bağlı olarak malzemenin mekanik özelliği ve lineer genleşme katsayısıdeğişmektedir. Fiber yönlenmesinin kontrolü, farklı kriterlere bağlı olsa da, öncellikle kalıp tasarımınınve enjeksiyon kalıplama şartlarının optimize edilmesi ile sağlanmaktadır. Bu çalışmada, %30 cam fibertakviyeli polipropilenin farklı şartlardaki enjeksiyonu ile akışa paralel fiber yönlenmesinin gerçekleştiğikayma tabakası kalınlığının arttırılması amaçlanmıştır. Taguchi L9 matrisine göre deneysel çalışmagerçekleştirilmiştir. Çalışmada, kalıp sıcaklığı, ergiyik sıcaklığı ve enjeksiyon hızı, girdi parametreleriolarak kabul edilmiştir. Elde edilen numunelerdeki akış yönüne paralel yönlenmenin gerçekleştiği kaymatabakası kalınlığı ise çıktı olarak belirlenmiştir. Kayma tabakasının kalınlığı, elektron mikroskobundanalınan görüntüler üzerinden ölçülmüştür. Elde edilen fiber yönlenmesine bağlı olarak, malzemenindinamik mekanik davranışı ile Dinamik Mekanik Analiz (DMA) uygulanarak irdelenmiş, depolamamodülü, kayıp modülü ve tan delta değerleri elde edilmiş. Çalışmanın sonucunda, yüksek kalıp veerigiyik sıcaklığı değerlerinde, kayma tabakası kalınlığının arttığı belirlenmiştir. Kayma tabaka kalınlığıarttığında, depolama modülü ve kayıp modülü değerlerinin yükseldiği görülmüştür.

Investigation of Fiber Orientation in Injection Molding of Glass Fiber Reinforced Polymers

Controlling fiber orientation in plastic injection of glass reinforced polymers is important due to the improvement of the properties of the material. The mechanical properties and linear expansion coefficient of the material change according to the orientation of the fibers parallel to the flow direction or random orientation. The controlling of the fiber orientation depends on several critera but specifically, this is provided by the optimization of the mold design and injection molding parameters. In this study, 30% glass fiber reinforced was injectied under various injection molding conditions in order to increase the fiber orientation paralel to the flow direction. The experimental study was carried out according to the Taguchi L9 orthogonal array. The mold temperature, melt temperature and injection rate were accepted as input parameters. The thickness of the shear layer in which the fibers oriente paralel to the flow direction was taken as output. The shear layer thickness was measured over the images obtained by scanning electrone microscope. In order to investigate the dynamic mechanical behavior of the material depending on fiber orientation, Dynamical Mechanical Analysis (DMA) was applied. Storage modulus, loss modulus and tan delta values were obtained. As a result, it has been observed that higher mold temperature and melt temperature values increased shear layer thickness. Higher shear layer thickness induced higher storage modulus and loss modulus.

PDF

___

Agboola, B.O., Jack, D.A. and Smith, S.M., 2012. Effectiveness of recent fiber-interaction diffusion models for orientation and the part stiffness predictions in injection molded short-fiber reinforced composites. Compos Appl Sci Manuf., 43(11), 1959– 1970.
Amash, A. and Zugenmajer, P., 1997. Thermal and Dynamic Mechanical Investigations on Fiber Reinforced Polypropylene Composites. Journal of Applied Polymer Science, 63(9), 1143-1154.
Bajracharyaa, R.M., Manalo, A.C., Karunasena, W. and Lau, K.T., 2016. Experimental and theoritical studies on the properties of injection moulded glass fibre reinforced mixed plastic composites. Composites: Part A, 84, 393-405
Barbosa, S.E. and Kenny, J.M., 1999. Analysis of the relationship between processing conditions – fiber orientation final properties in short fiber reinforced polypropylene. Journal of Reinforced Plastic Composites, 18(5), 413-420.
Chen, C.S., Chen, T.J., Chen, S.C. and Chien, R.D., 2006. Optimization of the injection molding process for short-fiber-reinforced composites. Mech Compos Mater, 47(3), 359–368.
Dong, C., 2014. Experimental investigation on the fiber preform deformation due to mold closure for composites processing. Int J Adv Manuf Technol, 71(1-4), 585–591.
Goris, S., Gandhi, U., Song, Y.Y. and Osswald, T.A., 2016. Analysis of the Process-Induced Microstructure in Injection Molding of Long Glass Fiber-Reinforced Thermoplastics. SPE ANTEC Indianapolis, 318-326.
Hashemi, S. and Lepessova, Y., 2007. Temperature and weldline effects on tensile properties of injection moulded short glass fibre PC/ABS polymer composite. J Mater Sci Res, 42(8), 2652–2661.
Karsli, N.G. and Aytac, A., 2013. Tensile and thermomechanical properties of short carbon fiber reinforced polyamide 6 composites. Compos. B Eng.51, 270–275.
Katti, S.S. and Schults, M., 1982. The microstructure of injection molded semi crystalline polymers. A review. Polymer Engineering and Science,22(16), 1001-1017.
Kim, E.G., Park, J.K and Jo, S.H., 2001. A study on fiber reinforced orientation during the injection molding of fiber reinforced polymeric composites. Journal of Material Processing Technology, 111, 225-232.
Kim, J.W. and Lee, D.G. 2006. Fiber Orientation state depending on injection mold gate variations during FRP injection molding. Key Engineering Materials, 321, 938-941.
Köpplmayr, T., Milosavljevic, I., Aigner, M., Hasslacher, R., Plank, B., Salaberger, D. and Miethlinger, J., 2013. Influence of fiber orientation and length distribution on the rheological characterization of glass-fiber filled polypropylene. Polym Test, 32, 535–544.
Li, X.P., Zhao, G.Q. and Yang, C., 2014. Effect of mold temperature on motion behaviour of short glass fibers in injection molding process. Journal of Advanced Manufacturing Technology, 73(5), 639- 645.
Liu Y., Zhang, X., Song, C., Zhang Y., Fang Y., Yang, B. and Wang, X., 2015. An effective surface modification of carbon fiber for improving the interfacial adhesion of polypropylene composites. Mater &Design, 88, 810- 819.
Meyer, K.J., Hofmann, J.T. and Baird, D.G., 2013. Initial conditions for simulating glass fiber orientation in the filling of center-gated disks. Compos Appl Sci Manuf, 49, 192–202.
Minnick, R.A. and Baird, D.G., 2016. Effects of Injection Molding Processing Parameters on Experimental Fiber Length Distribution of Glass Fiber-Reinforced Composites. SPE ANTEC Indianapolis, 368-372.
Mortazavian, S. and Fatemi, A., 2015. Effects of fiber orientation and anisotropy on tensile strength and elastic modulus of short fiber reinforced polymer composites. Composites Part B: Engineering, 72, 116- 129.
Pazour, S., 2014. Improved Quality Prediction of Injection Molded Fiber Reinforced Components by Considering Fiber Orientations. Altair Conference, Presentations, Munich.
Peng, X., Qin, J. and Jiang, Y., 2015. An Approach for Predicting Fiber Orientation Distribution in Plastic Injection Molding of Composites. British Journal of Applied Science & Technology, 7(2), 186-194.
Serrano, A., Espinach, F.X., Julian, F., Rey, R., Mendez, J.A. and Mutje, P., 2013. Estimation of the interfacial shears strength, orientation factor and mean equivalent intrinsic tensile strength in old newspaper fiber/ polypropylene composites. Compos B Eng, 50, 232–238.
Shie, J.R., 2008. Optimization of injection molding process for contour distortions of polypropylene composite components by a radial basis neural network. Int J Adv Manuf Technol, 36, 1091–1103.
Shokri, P. and Bhatnagar, N., 2012. Effect of the post- filling stage on fiber orientation at the mid-plane in injection molding of reinforced thermoplastics. Phys Procedia, 25, 79–85.
Singh, P. and Kamal, M.R., 1989. The effect of processing variables on microstructure of injection molded short fiber reinforced polypropylene composites. Polymer Composites,10 (5), 344-351.
Thi, T.B.N, Morioka, M., Yokoyama, A., Hamanaka, S., Yamashita, K. and Nonomura, C., 2015. Measurement of fiber orientation distribution in injection-molded short-glass-fiber composites using X-ray computed tomography. AIP Conference Proceedings, 1664, 1-6.
Tzeng, C.J., Yang, Y.K., Lin, Y.H. and Tsai, C.H., 2012. A study of optimization of injection molding process parameters for SGF and PTFE reinforced PC composites using neural network and response surface methodology. Int J Adv Manuf Technol, 63 (5–8), 691–704.
Vincent, M., Giroud, T., Clarke, A. and Eberhardth, C., 2005. Description and modelling of fiber orientation in injection molding of fiber reinforced thermoplastics. Polymer, 46, 6719-6725.
Yaguchi, H., Hojo, H., Lee, D.G. and Kim, E.G., 1995. Measurement of planar orientation of fibers for reinforced thermoplastics using image processing. International Journal Polymer Processing, 10, 262- 269.
Yashiro, S., Sasaki, H. and Sakaida, Y., 2012. Particle simulation for predicting fiber motion in injection molding of short-fiberreinforced composites. Compos Appl Sci Manuf, 43(10), 754–1764.