1.2 Fabric Analysis: 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

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

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.

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.

Identification of warp and weft

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 tape

r 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: 100)(%

f

fy

l

llcCrimp

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

L

GtexdensityLinear

1000)(

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.