LİF AÇMA İŞLEMİNİN CAM ELYAF TAKVİYELİ EPOKSİ KOMPOZİTLERİN MEKANİK VE YALITIM ÖZELLİKLERİ ÜZERİNDEKİ ETKİSİ

Bu çalışmada, farklı lif boy/çap oranına sahip kırpılmış cam elyaflar, basınçlı hava ile açılmış elyaf demedi haline getirilmişve epoksi matrisin takviyelendirilmesinde kullanılmıştır. Ağırlıkça %5, %10 ve %15 oranında elyaf takviyesiyle elle yatırmayöntemiyle üretilen kompozitlere çekme dayanımı, eğilme dayanımı ve ısıl iletkenlik testleri yapılmıştır. Elde edilen sonuçlar, eşişlem parametrelerinde üretilen kırpılmış cam elyaf takviyeli kompozitler ile kıyaslanmıştır. Lif açma süresinin kullanılan kırpılmışlifin boy/çap oranına bağlı olmadığı ve lif boyunun lif açma süresi üzerinde lif çapına göre daha önemli etkiye olduğu görülmüştür.Uzun lif boyuna sahip kırpılmış cam elyafların lif açma işlemine daha hızlı cevap verdiği gözlenmiştir. Lif açma işlemi genel anlamdakompozitlerin çekme ve eğilme dayanımlarında düşüşe ancak yalıtım özelliklerinde artışa neden olmuştur. Lif boy/çap oranı 4.5mm/13 µ olan cam elyaf tipi için, açılmış elyaf demedi kullanılarak daha düşük konsantrasyonda yüksek çekme dayanımı eldeedilmesi söz konusudur. Eğilme dayanımı üzerinde lif boyunun etkisinin yüksek olduğu ve açma işlemi sonrasında, lif boy/çaporanları 3 mm/13 µ ve 4.5 mm/10.5 µ olan cam elyaf tiplerinin eğilme dayanımı davranışlarının daha tutarlı hale geldiği tespitedilmiştir. Lif açma işleminin kompozitlerin ısıl iletim katsayılarının düşmesinde etkili olduğu ve kompozitleri daha yalıtkan halegetirdiği görülmüştür.

EFFECT OF FIBER OPENNING PROCESS ON MECHANICAL AND INSULATING PROPERTIES OF GLASS FIBER REINFORCED EPOXY COMPOSITES

In this study, chopped glass fibers with various fiber aspect ratios were opened via pressurized air application and obtained fiber bundles were used for reinforcing of epoxy matrix. Composites with fiber contents of 5%, 10% and 15% in weight were produced by hand lay-up technique and these samples were exposed to tensile, flexure and thermal insulation testing procedures. Results were compared with chopped glass fiber reinforced epoxy composites produced with identical process parameters. The results showed that openning process period was not related with fiber aspect ratio of chopped fiber and fiber length had an important effect on opening process period than that of fiber diameter. Long chopped fibers gave quick response to air pressure application. In general, openning process caused decrease on tensile and flexural strengths of composites but increase on thermal insulating characteristics. For 4.5 mm/13 µ samples, opened fiber reinforced composites exhibited high tensile resistance at low concentration values. Flexural strengths of composite were highly affected from fiber length parameter in both chopped and opened fiber reinforced composites and flexural behaviours of composites reinforced with (3 mm/13 µ) and (4.5 mm/10.5 µ) glass fibers having different fiber aspect ratios became more consistent after openning process. Thermal conductivity coefficients of composites decreased by using openned fibers as reinforcing agent and composites exhibited more insulating characteristics.

PDF

___

1. Panthapulakkal, S., Raghunanan, L., Sain, M., Birat, K.C., Tjong, J., (2017), Natural Fiber and Hybrid fiber Thermoplastic Composites: Advances in Ligthweighting Applications, In Green Composites, C. Baillie, R. Jayasinghe (Edt), Woodhead Publishing, Cambridge.
2. Nair, A.B.; Joseph, R., (2014), Eco-friendly Bio-Composites Using Natural Rubber (NR) Matrices and Natural Fiber Reinforcements, In Chemistry, Manufacture and Applications of Natural Rubber, S. Kohjiya, Y., Ikeda (Edt), Woodhead Publishing, Cambridge.
3. Agarwal, B.D., Broutman, L.J., Chandrashekhara, K., (2017), Analysis and Performance of Fiber Composites, John Wiley & Sons, Hoboken.
4. Kurt, G., (2006), Lif İçeriği ve Su/Çimento Oranının Fibro Betonun Mekanik Davranışına Etkileri, Yüksek Lisans Tezi, İstanbul Teknik Üniversitesi, İstanbul.
5. Şahin, Y., (2006), Kompozit Malzemelere Giriş, Seçkin Yayıncılık, Ankara.
6. Zinck, P., Mäder, E., Gerard, J.F., (2001), Role of Silane Coupling Agent and Polymeric Film Former for Tailoring Glass Fiber Sizings from Tensile Strength Measurements, Journal of Materials Science, 36, 5245-5252.
7. Prakash, S., (2019), Experimental Investigation of Surface Defects in Low-Power CO2 Laser Engaving of Glass Fiber-Reinforced Polymer Composite, Polymer Composites. 40, 4704–4715.
8. Trantina, G., Mimmer, R., (1994), Structural Analysis of Thermoplastic Components, McGraw Hill, New York.
9. Ekşi, O., (2007), Plastik Esaslı Malzemelerin Isıl Şekil Verme Özelliklerinin İncelenmesi, Yüksek Lisans Tezi, Trakya Üniversitesi, Edirne, Türkiye.
10. Mallick, P.K., (2007), Fiber-Reinforced Composites: Materials, Manufacturing and Design, Marcel Decker Incorporated Publishing, New York.
11. Lee, H., Neville, K., (1957), Epoxy Resins: Their Application and Technology, Mc Graw-Hill, New York.
12. Peck, J., (2007), Sculpture as Experience, Krause Publications, Wisconsin.
13. Hancock, P., Cuthbertson, R.C., (1970), The Effect of Fibre Length and Interfacial Bond in Glass Fibre-Epoxy Resin Composites, Journal of Materials Science, 5, 762-768.
14. Kinsella, M., Murray, D., Crane, D., Mancinelli, J., Kranjc, M., (2001), Mechanical Properties of Polymeric Composites Reinforced with High Strength Glass Fibers, International SAMPE Technical Conference, 33(1), 1644-1657.
15. Thomason, J.L., (2002), The Influence of Fiber Length and Concentration on the Properties of Glass Fiber Reinforced Polypropylene: Injection Moulded Long and Short Fiber PP, Composites Part A: Applied Science and Manufacturing, 33(12), 1641–1652.
16. Obukuro, M., Takahashi, Y., Shimizu, H., (2008), Effect of Diameter of Glass Fibers on Flexural Properties of Fiber Reinforced Composites, Journal of Dental Materials, 27 (4), 541-548.
17. Bagherpour, S., (2012) Fiber Reinforced Polyester Composites, In Polyester, H. El-Din, M.S. Croatia (Edt), Intech Open Access Publication.
18. Mader, E., (2017), Glass Fibers: Quo Vadis?, Fibers, 5(10), 1-4.
19. ASTM D3039, Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials.
20. EN ISO 178:2003, Plastics: Determination of Flexural Properties.
21. ASTM C1113, Standard Test Method for Thermal Conductivity of Refractories by Hot Wire (Platinum Resistance Thermometer Technique).
22. Chawla, K.K., (2016), Glass Fibers, In Reference Module in Materials Science and Materials Engineering, S. Hashmi (Edt), Elsevier, Amsterdam.
23. Mark, R.E., Borch, J., Habeger, C., (2002), Handbook of Physical Testing of Paper, CRC Press, New York.
24. Goris, S., Back, T., Yanev, A., Brands, D., Drummer, D., Osswald, T.A., (2018), A Novel Fiber Length Measurement Technique for Discontinuous Fiber-Reinforced Composites: A Comparative Study with Existing Methods, Polymer Composites, 39 (11), 4058-4070.
25. Metten, M., Cremer, M., (2000), Langfaserverstärkte Thermoplaste Spritzgießen: Verfahrensparameter Beeinflussen die Faserlänge, Kunststoffe Plast Europe, 90(1), 80-83.
26. Ozsoy, N., Ozsoy M., Mimaroglu, A., (2017), Mechanical and Tribological Behaviour of Chopped E-Glass Fiber-Reinforced Epoxy Composite Materials, Acta Physica Polonica A, 132, 832- 856.
27. Yıldızel, S., (2017), Mechanical and Thermal Behaviors Comparison of Basalt and Glass Fibers Reinforced Concrete with Two Different Fiber Length Distributions, Challenge Journal of Structural Mechanics, 3(4), 155–159.
28. Omid, T., Venus, M., Sharafeddin, F., Asghar, A., (2012), Effect of Glass Fiber Length on Flexural Strength of Fiber-reinforced Composite Resin, World Journal of Dentistry, 3, 131-135.
29. Lampman, S., (2003), Characterization and Failure Analysis of Plastics, ASM International, Ohio.
30. Lee, S.M., (1992), Handbook of Composite Reinforcements, John Wiley & Sons, New York.