1.2 Fabric Analysis:

1.2 Fabric Analysis: Ⅰ. Making samples Ⅱ. Identification of face or back of the fabric Ⅲ. Identification of warp and weft Ⅳ. Density measurement Ⅴ. Crimp measurement Ⅵ. Linear density (tex) measurement Ⅶ . Fiber identification Ⅷ .Fabric weight Ⅸ. Fabric structure and color arrangement Purposes: Get to know the fabric parameters Reasons for knowing the fabric parameters: The properties of the fabric are closely linked to fabric parameters

Ⅰ. Making samples • The sample should properly represent the characteristics of the fabric. Location: • The sample should not be selected near the edge of the fabric. The distance from the selvage must be more than 5 centimeters, and that from the end of the fabric must be more than 1.5 to 3 meters.

Size: • The size of the sample varies depending on the characteristics of the fabric, 15cm ×15cm are suitable for simple structure and small pattern fabrics, and 20cm×20cm for fabrics with big pattern.

Ⅱ. Identification of face or back of the fabric • The face of a fabric has a clear colour or patterns. • For rib or corded fabrics, the face are usually more dense and smooth. • For pile fabrics, the face has piles. • For double fabrics, the face has higher density, and better materials. • For terry fabrics, the face has denser loops.

Ⅲ. Identification of warp and weft • The warp is always parallel with selvage. • The warp may be sized, and the weft not. • The warp usually has a bigger density . • The warp direction may have reed marks. • The warp is more often using ply yarn.

Identification of warp and weft • The Z-twist yarns are used for warp, and S-twist for weft if the warp and weft are different in twist direction. • The warp usually has higher twisted yarns. • The warp is usually better in quality. • For terry fabrics, the warp forms the loops. • For striped fabrics, the warp is parallel to the stripes. • Warp can be easily arranged with different kinds of yarns.

Ⅳ. Density measurement • The density of the fabric is very important, as it directly affects the fabric’s appearance, handle, thickness, strength, warmth retention. There are two ways to measure it. a: Direct measurement b: Indirect measurement

Direct measurement Thread density=threads counted/2.5=threads per cm Indirect measurement-woven fabric This is carried out by using an optical device known as a taper line grating.

Ⅴ. Crimp measurement • Crimp refers to the amount of bending that is done by a thread as it interlaces with the threads that are lying in the opposite direction of the fabric • Formula: Where: ly is the length of the yarn lf is the length of the fabric

Crimp tester

Ⅵ .Linear density (tex) measurement Where : G ─ The weight of the thread in gram at the official moisture regain L─ The length of the thread in meter The thread linear density indicates the weight in gram of 1000m of thread

Ⅶ. Fiber identification • a) Microscopically examination of the longitudinal and cross-sectional views of the fiber. • b) Burning test • c) The use of solvents • d) Other chemical tests • e) Staining • f) Melting point determination • g) Fiber density

Ⅷ .Fabric weight • Weighting measurement: Mass per unit area(g/m2)=specimen mass (g) ×100 Where: mass per unit area is expressed in grams per square meter specimen is 10cm×10cm • Calculating measurement: fabric weight is the sum of the weight of warp and weft threads Where:p1—warp density(ends/10cm) p2--- weft density (picks/10cm) a1--- warp take-up(%) a2 --- weft take-up(%) Tex1—warp linear density Tex2–- weft linear density

Ⅸ. Fabric structure and colour arrangement • It is necessary to know the way in which the fabric is constructed. For example, twill weave or sateen. This can be obtained viewing the fabric with a piece of magnifying glass or a low magnification microscope.

Home work: • Analyze the given samples, get all the parameters you could.

1.2 Fabric Analysis: