Publication: El yatırma yöntemi ile elyaf takviyeli kompozit yapıların üretilmesi ve özellikleri
Abstract
EL YATIRMA YÖNTEMİ İLE ELYAF TAKVİYELİ KOMPOZİT YAPILARIN ÜRETİLMESİ VE ÖZELLİKLERİ El yatırma yöntemi ile elyaf takviyeli kompozit yapıların üretilmesinde genellikle keçe ve dokuma yapıdaki lifler takviye elemanı olarak seçilirken dayanımı ve elastikliğin arttırılması için cam ve karbon elyafından yapılmış çok eksenli kumaşların kullanıldığı bilinmektedir. Kompozit malzemelerin en basit uygulama yöntemlerinden olan el yatırma metodunda, bu amaçla yukarıda bahsedilen ve bilinen bu uygulamaların yerine bambu ve keten elyafı ve fitil şeridi kullanılarak doğal kökenli liflerde el yatırma yöntemi ile kompozit üretilmeye çalışılmıştır. Çalışmada 1.5 dtex/ 38 mm uzunluğunda bambu elyafı, Nm 0.93 bambu fitili ve ağartılmamış % 100 keten elyafı kullanılarak vinilester reçine ile farklı takviye yüzdelerinde çeşitli kompozit yapılar üretilmiştir. Üretilen doğal kökenli kompozit yapıların izod darbe dayanımı, çekme dayanımı ve üç nokta eğilme testleri yapılarak kırık yüzey analizleri elektron mikroskobunda incelenmiştir. Elde edilen sonuçlara göre bambu elyaf takviyeli kompozitlerde 3mm ve üstü uzunluklarda lif kullanımının mekanik özellikleri arttırdığı görülmüştür. Keten elyaf takviyeli numunelerde ise bambu elyafına göre daha iyi mekanik değerler elde edilmiştir. Keten elyafında yağ ve vaks tabakası uzaklaştırıldığında, işlem görmemiş elyafa göre daha iyi bir matris lif kaynaşmasının meydana geldiği görülmüş ve darbe dayanımında % 50’ye varan artışlar gözlemlenmiştir.
PRODUCTION OF FIBRE REINFORCED COMPOSITE STRUCTURES AND THEIR PROPERTIES BY THE HAND LAY-UP METHOD Generally felt and woven fabrics are selected as a reinforcement component of fibre reinforced composite structures which are produced with hand lay-up method. It is known that multiaxial fabrics consist of glass and carbon fibres are used to increase the mechanical properties. In this study, instead of glass and carbon fibres mentioned above, the composite structures with hand lay-up method by using natural fibers of flax bamboo and bamboo sliver were produced. At this study the composite structures with vinylester resin and bamboo fibres with 1.5dtex/ 38 mm staple length, Nm 0.93 bamboo sliver and 100 % unbleached flax fibres at different reinforcement ratios had been produced. After producing, the natural fiber reinforced composites three point bending, tensile strength and izod impact strength tests were carried out and fracture surfaces of the samples had been inspected on the scanning electron microscope. According to the results, it has been evaluated that bamboo fibres with 3 mm fibre length and above increases the mechanical properties of composite structures. The increament of the mechanical properties of the reinforced samples with flax fibres have shown considerably higher properties than bamboo reinforced fibres. Better combination has observed between resin and fibres of the samples which had been produced with flax fibres that are purified from wax and grease. Also approximately 50 % increament has been reached on the izod impact strength of these samples.
PRODUCTION OF FIBRE REINFORCED COMPOSITE STRUCTURES AND THEIR PROPERTIES BY THE HAND LAY-UP METHOD Generally felt and woven fabrics are selected as a reinforcement component of fibre reinforced composite structures which are produced with hand lay-up method. It is known that multiaxial fabrics consist of glass and carbon fibres are used to increase the mechanical properties. In this study, instead of glass and carbon fibres mentioned above, the composite structures with hand lay-up method by using natural fibers of flax bamboo and bamboo sliver were produced. At this study the composite structures with vinylester resin and bamboo fibres with 1.5dtex/ 38 mm staple length, Nm 0.93 bamboo sliver and 100 % unbleached flax fibres at different reinforcement ratios had been produced. After producing, the natural fiber reinforced composites three point bending, tensile strength and izod impact strength tests were carried out and fracture surfaces of the samples had been inspected on the scanning electron microscope. According to the results, it has been evaluated that bamboo fibres with 3 mm fibre length and above increases the mechanical properties of composite structures. The increament of the mechanical properties of the reinforced samples with flax fibres have shown considerably higher properties than bamboo reinforced fibres. Better combination has observed between resin and fibres of the samples which had been produced with flax fibres that are purified from wax and grease. Also approximately 50 % increament has been reached on the izod impact strength of these samples.