Introduction to Textile Fibers and Classification PDF

Introduction to Textile Fibers and Fiber Classification John Wirth TEX 210 Gaston College Lecture #2 Textile fibers and classification Textile fibers fall into 2 primary categories Natural Fibers Plant fibers – example cotton fiber...

Introduction to Textile Fibers and Fiber Classification John Wirth TEX 210 Gaston College Lecture #2 Textile fibers and classification Textile fibers fall into 2 primary categories Natural Fibers Plant fibers – example cotton fibers Animal fibers – example wool fibers Mineral fibers – example asbestos fibers Man-Made Fibers Synthetic – example polyester or nylon fibers Regenerated from natural source – example rayon, acetate or milk fibers Detailed Classification of Textile Fibers Natural vs Man-Made Fibers Natural Fibers Man-Made Fibers Fiber length variable Fiber length consistent Fiber diameter variable Fiber diameter consistent Not possible to change fiber Fiber structured can be structure varied Fiber defined by nature as Same fiber can be in staple or filament filament or staple Fiber density defined Fiber density can be varied Crimp determined by nature Crimp count and shape Limited natural color range easily varied Production cycle typically long Color can be varied and somewhat unpredictable Production cycle Fibers made from natural considerably shorter and polymers predictable Polymers for fibers made by chemical process Qualitative vs Quantitative methods of identifying textile fibers Qualitative methods can identify the type of fiber present For example, the fiber blend is comprised of polyester and cotton Quantitative methods can identify how much of each fiber is present For example, the fiber blend is 65% polyester and 35% cotton How can a textile fiber be identified? Selected qualitative methods – AATCC 20 for single fiber type Microscopy – determine physical shape/characteristic appearance and match to known images. Burn method – evaluate fiber response to flame, type of ash, smell and smoke Staining method – identify fiber type through color/shade achieved with various staining solutions Solubility Method – determine in which solution the fiber dissolves Melt Point – Thermoplastic fibers melt at different temperatures Burn testing example Fiber identification by burning Burn Testing Textile Fibers Source: AATCC 2022 Technical Manual Microscopic appearance evaluation of textile fibers Microscopy of textile fibers Quantitative Fiber Identification – AATCC 20A Used for blends of fibers Solubility method – good for relatively simple blends, i.e., Polyester/Cotton FTIR – precise method for determining which fibers are in a blend using IR Spectral analysis. Microscopic analysis to see which fibers are present and to count how many of each are in a cross-section Usually, multiple methods need to be utilized with complex or multi-fiber blends Solubility Method Example Polyester/Cotton – weigh fabric before solubility analysis. Submerge fabric in 70% Sulfuric acid for 30 minutes. This burns off the cellulose Rinse and dry remaining fabric and weigh again. Weight before – Weight after = weight of cotton Depending on which fibers are suspected in the blend there is a specific order to be followed in AATCC 20A test method to obtain accurate results Infrared spectra of various fibers – FTIR method Use of FTIR to identify textile fibers Melting point of Textile Fibers Impact of temperature on thermoplastic fibers Homework Look through your closet at home and check the tags of 10 different clothing articles to see the fiber composition (i.e. 100% cotton, 70% Cotton 30% Polyester, etc.) Were there any fibers that you had never heard of? Were there common themes for fiber content? What fibers were typically closer to the skin What were usually in t-shirts, dress clothes, undergarments, jackets, swimsuits, etc. How would you define how those fabrics feel and perform?