Yavuz ÇAKIR, Ahmet ÖZDEMİR, Abdulmecit GÜLDAŞ

Plastik ürünlerde çekme miktarına etki eden enjeksiyon parametrelerinin incelenmesi

Enjeksiyonla kalıplanan plastik ürünlerde meydana gelen çekme, dar tolerans aralıklarında imal edilen makine parçalarının yerini almaya başlayan parçalar için ciddi bir problemdir. I 20 - 3 polietilen plastik ürünlerdeki çekme miktarına, enjeksiyon parametrelerinin ve kalıp özelliklerinin etkilerinin deneysel olarak araştırıldığı bu çalışmada, yapılan deneylerle enjekte sıcaklığı, enjekte basıncı, katkı maddesi oranı ve kalıplama süresinin plastik ürünlerdeki çekme miktarına olan etkileri grafikler halinde sunulmuştur. Katkı maddesi olarak endüstride yaygın kullanılan 1 668 polietilen tercih edilmiştir. Enjekte basıncı ve kalıplama süresinin artması ile çekmenin azaldığı, katkı maddesi ve enjekte sıcaklığının artırılması ile çekmenin arttığı tespit edilmiştir.

The shrinkage which occurs in the plastic parts molded by injection is a very serious problem deu to these parts replaced the mechanical products that are manufactured into very small tolerances. In this study, the shrinkage of a 1 20-3 plastic product which is affected from the injection parameters and the mold properties is experimentally investigated. In the experiments it was graphically obtained how the injection temperature, the injection pressure, the proportion of supplement material and the injection duration effect the shrinkage amount of a plastic part. 1 668 polyethylene is selected for a supplement material. It was found that the shrinkage amount of plastic decreases with the increase the injection pressure and the duration.

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1. Rosat, O., Donald, U., 1999, Injection Molding Handbook, Second Edition, Kluwer Academic Publishers, Boston/London.

2. Pye, P. G. W., 1998, Injection Mold Design, Fourth Edition, John Wily & Sons Inc., New York.

3. Buckleitner, E. V., 1995, Plastic Mold Engineering Handbook, 5. Ed., Chapman & Hall, New York.

4. Menges, G., Mohren, P., 1983, How To Make Injection Molding, Hanser Publisher, New York.

5. Turaçlı, H., 2000, Enjeksiyon Kalıp İmalatı, PAGEV Yayınları, İstanbul

6. Akyüz, Ö. F., 1999, Plastikler ve Plastik Enjeksiyon Teknolojisine Giriş, PAGEV Yayınları, İstanbul

7. Çakır, Yavuz, 2000, I 20-3Polietilen Üretilen Parçada Çekme Miktarına Etki Eden Enjeksiyon Parametrelerinin Araştırılması, Yüksek Lisans Tezi, Gazi Ün. Fen Bilimleri Enstitüsü, Ankara

8. F. Mark, M. Bikales, G. Overberger, G.Menges, 1989, Encyclopaedia of Polymer Science and Engineering, W'iley Interscience, New York.

9. Kohan, I. M., 1995, Naylon Plastics Handbook, Hanser/ Gardner Publications, Inc., Cincinnati.

10. Michaeli, Greif, Kaufmann, Vossebürger, 1995, Training in Plastic Tecnology, Hanser/ Gardner Publications, Inc., Cincinnati.

11. Carly, F. J., Levy, S., 1989, Plastics Extrusion Technology Handbook, Second Edition, Industrial Press, Inc., New York.

12. Henser, F., 1997, Plastics Extrusion Technology, 2nd Edition, Hanser/ Gardner Publications, Inc., Cincinnati.

13. Osswald, A. T., 1998, Polymer Processing Fundamentals, Hanser/ Gardner Publications, Inc., Cincinnati.

14. Cappelletti, R. M., 1995, International Plastics Handbook, 3rd Edition, Hanser/ Gardner Publications, Inc., Cincinnati.

15. Lee, Ho-sang, 1999, In-Plane Deformation Analysis of Plastic Parts in the Injection Molding Process, Journal of Injection Molding Technology, Vol 3, No 1, 11-20

16. Chang, Tao C Faison, Ernest, 1999, Optimisation of Weld Line Quality in Injection Molding Using an Experimental Design approach, Journal of Injection Molding Technology, Vol 3, No 2, 61-66

17. Couglin, J., 1992, Melt-Temperature detection problems you may know you have, Modern Plastics Magazine, Pp 101-105.

18. Jaworski, J. M., 1997, Usin CAS Injection Molding Simulation Predict Overpack, Voids and Sing, ANTEC’ 97, 1161 33642-3646

19. Kim, S. J., Lee (SNU), K., Kim(LH) Y. L., 1996, Optimisation of Injection Molding Conditions Using Genetic Algorithm, Proc Spıe, Vol 2644 173-180

20. Öz, U, 1997, Bilgisayar Destekli Plastik Enjeksiyon Kalıp Tasarımı, Yüksek Lisans Tezi, Yıldız Teknik Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul

21. Wang, H., Prystay ,M., Hetu, F-J., Jen, C. K., 1996, Gap Between Mold and Part and Its Effect on Cooling of Injection-molded Plastics, ANTEC’ 96,1049-1053.

22. Lam, L.C., Seam L. W., 1997, Optimisation flow in plastic injection molding, Journal of Materials Processing Technology, Vol 72, No 1, 333-341.

23. Rezayat, M., Stafford, O. R., 1991, A Thermoviscoelastic Model for Residual Stress in Injection Molded Thermoplastics, Polymer Engineering and Scince, Vol 31, No 6, 393-398.

24. Deveci, Kemal, 1977, Plastik Kalıp Konstrüksiyonu, Teknik Öğretmen Okulu, Ankara.

25. Wang, K.K., Hieber, C. A. and Chiang H. H., 1991, A Unified Simulation of the Filling and Postfilling Stages in Injection Molding. Part I: Formulation, Polymer Engineering and Scince, Vol 31, No 2, 116-124.

26. Tamma, K. K., Dowler, B. L. ve Railkar, S. B., 1988, Computer Aided Applications to Injection Molding: Transfinite / Finite Element Thermal / Stress Response Formulations, Polymer Engineering and Scince, Vol 28, No 7, 421-428.

27. Akay, S. ve Özden, S., 1996, Prediction of Process-Induced Warpage in Injection Molded Termoplastics, Polymer Engineering and Science, Vol 36, No 13, 1839-1846.

28. Dininger, J., 1994, Three Critical Measurements on Injection Molding Processes, Polymer Engineering and Science, Vol. 37, No 6, 2159-2164.

29. TURGUT, N., 1994, Termoplastik Esaslı Makine Parçaların İmalinde Kullanılan Enjeksiyon Kalıplarının Soğutulması, Yüksek Lisans Tezi, Yıldız Teknik Üniversitesi, İstanbul .

30. Kovarski, L. A., 1994, Molecular Dynamics of Additives in Polymers, Utrecht, The Netherlands.

31. Sepe, P. M., 1998, Dynamic Mechanical Analysis for Plastics Engineering, Plastics Design Library, Norwich.

32. Brydson, J. A., 1975, Plastic Materials, London.

33. Douglas M. Bryce, 1991, Thermoplastic Troubleshooting for Injection Molders, SPE Series, Pp 15-32.

34. Jeffrey, Dininger, 1997, Engineering Technologies, Lorin County Community College, Elyria, Ohio.

35. C-MOLD News, April 1998, Molding Intelligence, Vol. 11, No. 1.

36. PETKİM, 1977, (I 20-3) ve (I 668) polietilen malzeme katalogu, İzmit/Yarımca

37. ASTM 1238 ve ASTM 1505