Enset dokuma kumaş yapılarının ses yutum ve biyobozunur kompozit malzeme geliştirilmesi uygulamalarında kullanımı üzerine bir araştırma

Tekstil endüstrilerindeki yeni gelişmeler, boyutsal stabilite, su emicilik, nefes alabilirlik gibi tekstil kumaşları ve bitim özelliklerinin performansını geliştirmektedir. Tekstil liflerinin yapıları ve özellikleri; kompozitlerin yanı sıra iplikler, kumaşlardan oluşan malzemelerin mekanik özellikleri üzerinde büyük bir etkiye sahiptir. Uzun süredir metaller, en çok tercih edilen yapı malzemeleri olarak kullanılmıştır. Bununla beraber; insanların hızla büyüyen talepleri, araştırmacıları yüksek spesifik mukavemet ve elastisite modülüne sahip yeni kompozit malzemelerin geliştirilmesine itmiştir. Petrokimya ürünleri, sadece çevre dostu olmayan ürünler olmayıp aynı zamanda üretim, kullanım ve atıkların yok edilmesi süresince ciddi sağlık problemlerini oluşturmaktadır. Son zamanlarda araştırmacılar ve üreticiler, yeşil kompozit uygulamalar için yaprak, gövde ve meyvelerden özütü elde edilen doğal lif takviyeli kompozit malzemeler üzerinde araştırmalarını odaklamıştır. Doğal lifler, doğada bol miktarda bulunur, hafif, düşük maliyetli ve konvansiyonel lifler içerisinde iyi mekanik mukavemete sahip olan yenilenebilir doğal malzemelerdir. Doğal kaynaklardan elde edilen takviye ve matriks elemanları olarak kullanılan sentetik lifler ve reçinelerin yeri, kompozit malzeme sektörlerindeki ekonomiksel, sağlık sorunları ve çevresel problemleri önlemesine iyi alternatiftir. Bu doktora tezi çalışmasında, hafif nitelikli yapı uygulamaları için mekanik özelliklerinin geliştirilmesi ile yenilikçi tekstil kumaşları takviyeli yeşil kompozit malzemelerin karakterizasyonu ve araştırması üzerine odaklanılmıştır. Tekstil kumaşları, bu çalışmada takviye elemanları olarak kullanılmıştır. Yeni biyoreçine elemanları, 75:25, 70:30, 65:35, 60:40, 55:45 and 50:50 gibi çeşitli oranlarla Akasya tortillas ve Bosveliya papirifera karışımıyla hazırlanmıştır. Dokuma kumaş konstrüksiyonu ve çok katlı kumaş takviyeli yeşil kompozit malzemelerin, mekanik ve akustik performansları çalışılmıştır. Ayrıca nano lifler, α-amilaz enzim ön terbiyesi ve mekanik öğütmeyle üretilmiştir. Bu nanolifler; yüksek boyutsal stabilite, spesifik mukavemet, daha geniş yüzey alanı ve biyobozunabilir ürünler gibi benzersiz özelliklere sahip daha gelişmiş tekstil yapılarının üretilebilmesi için kullanılacaktır.The rapid developments of technology in textile industries have been improving the performance of textile fabrics and finishing properties such as durability, water replants and breathability. The natures and properties of textile fibers have a major impact on the physical and mechanical properties of materials made from them such as yarns, fabrics as well as composites. For a long period of times, metals have been used as the most preferred structural materials. However the rapid growing and unlimited demands of human being have pushed researchers to innovate new materials called composite materials, having high specific strength and stiffness. Petrochemical based composite materials are not only non-ecofriendly products but also they bring a serious health problems during their manufacturing, usage and waste disposals. Recently, researchers and manufacturers have focused on natural fiber reinforced materials obtained from leaf, bast and fruit for green composite applications. Natural fibers are abundantly available, light weight, low cost and renewable with good mechanical strength. Substituting of commercially used synthetic fibers and resins by naturally existing resources as a reinforcing material and matrix are the best alternative to overcome economic, health hazard and environmental problems in composite manufacturing sectors. This Ph.D dissertation focuses on the investigation and characterization of novel textile fabric reinforced green composite materials and enhancing their mechanical properties for light weight structural as well as sound absorption applications. Enset woven fabrics were used as reinforcing materials for this study. A new bio resin material was prepared by mixing separately prepared acacia tortillas and frankincensepapyrifera bio resins at different ratios such as 75:25, 70:30, 65:35, 60:40, 55:45 and 50:50. Mechanical and sound absorption performance of enset fabric reinforced bio composites was studied with special reference to bio resin preparation ratio and number of fabric layer. Also, enset nano fibers were manufactured by α-amylase enzyme treatment and mechanical hammering using enset fibers and enset fabrics. These nano fibers would be used to produce more advanced textile structures having unique properties such as higher weight to strength ratio, large surface area and bio-degrability.Alfa Kimya Sanayi ve Ticaret A.ŞWollo UniversityYurtdışı Türkler ve Akraba Topluluklar Başkanlığı (YTB

Comparative Study on the Mechanical Properties of Weft Knitted and Warp Fabric Reinforced Composites

Knitted fabric composites occupy a special interest in the field of engineering and materials science because of their easy to form complex component and high impact energy absorption. Mechanical tests were carried out in the course, wale and slanting directions of the knitted fabric reinforced composites. The stress-strain curves and failure modes of warp and weft knitted fabrics were investigated and compared. The test results revealed from the composite structure fabricated from warp knitted fabric shown better mechanical properties than weft knitted fabric because of the warp knitted fabric distinct by the process of overlap between the stitches that gave better resistance

Comparative Study on the Mechanical Properties of Weft Knitted and Warp Fabric Reinforced Composites

Knitted fabric composites occupy a special interest in the field of engineering and materials science because of their easy to form complex component and high impact energy absorption. Mechanical tests were carried out in the course, wale and slanting directions of the knitted fabric reinforced composites. The stress-strain curves and failure modes of warp and weft knitted fabrics were investigated and compared. The test results revealed from the composite structure fabricated from warp knitted fabric shown better mechanical properties than weft knitted fabric because of the warp knitted fabric distinct by the process of overlap between the stitches that gave better resistance

A comparative study on the acoustic absorption properties of green synthesis cellulose nano enset fibers

Natural fibers are becoming a valid alternative to most commercially used synthetic fibers in sound absorbing materials. In recent years, natural fibers have been considered as valid raw materials for producing ecofriendly sound absorbing materials at low cost. This paper presents a new study on enset nanofiber sound absorbing material which was prepared by enzyme treatment and mechanical hammering of the surface of enset woven fabric. Enset nano fiber (ENF) was fabricated by defibrillation of underutilized abundant byproduct fibers from the surface of enset woven fabrics into micro and nano-scale fibers by alpha-amylase enzyme treatment and then mechanical hammering. The purpose of this approach is that the product will be economic and environmentally friendly and also consumption of eco-friendly products is a serious concern of researchers and policymakers. The study was conducted by using impedance tube method and the sound absorption properties of enset micro and nanofibers in a frequency range of 1000 to 6000 Hz were studied by changing the diameter, thickness and percentage of enzyme concentration during fiber treatments. Parameters for enset nanofibers were: number of board layers (single, double, triple and fourth-layer having sample thickness of 10-13 mm), fine fiber size (micro and nano meter), and fine fiber treatments content (10, 15 and 20% w/v), pressing time (10 min), board density (0.95 g/cm3), press pressure (40 kg/m2) and press temperature (180 degrees C) were held constant. The experimental results revealed that at the same frequency (4500 Hz), the sound absorption coefficient value was improved by 176 and 213% when neat enset fabric was treated and hammered with 10 and 20 w/v % concentration of amylase enzymatic respectively. The maximum sound absorption of neat enset fabric and enset nanofibers was recorded as 0.47 and 0.99 around 5351 Hz respectively. These results indicate that the acoustic property of enset fiber was improved by 47% when neat enset fiber was converted into green enset nanofiber forms by enzyme treatment and mechanical hammering. The experimental results shown that green synthesis of fine fibers from the surface of woven fabric improved the maximum acoustic peak values by 43% (microscale) and 59% (nanofiber) compared with macroscale enset fibers. These simple and cost effective green cellulosic enset nanofiber formations would have a promising result for small scale acoustic enterprises

Comparative Study on the Mechanical Properties of Weft Knitted and Warp Fabric Reinforced Composites

Knitted fabric composites occupy a special interest in the field of engineering and materials science because of their easy to form complex component and high impact energy absorption. Mechanical tests were carried out in the course, wale and slanting directions of the knitted fabric reinforced composites. The stress-strain curves and failure modes of warp and weft knitted fabrics were investigated and compared. The test results revealed from the composite structure fabricated from warp knitted fabric shown better mechanical properties than weft knitted fabric because of the warp knitted fabric distinct by the process of overlap between the stitches that gave better resistance