TEK 232 WEAVING TECHNOLOGY I

1. Warp and weft yarn counts

2. Warp and weft densities
3. Weave
4. Crimp
5. Weight
6. Thickness
7. Cover
8. Fabric width and piece length

Weaving Technology II Emel

Önder/ Ömer Berkalp 2
 Warp density
Number of warp ends per unit length of fabric - spacing between warp
threads;
Units: ends per cm (e.p.c.) or ends per inch (e.p.i.);
Determined by reed number and denting

 Weft density
Number of picks per unit length of fabric - spacing between weft
threads
Units: picks per cm (p.p.c) or picks per inch (p.p.i.);
Determined by the rate of fabric take up during weaving.

 Count of Cloth
End Density X Pick Density ( X is not multiplication sign)

Weaving Technology II Emel

Önder/ Ömer Berkalp 3
 The closeness or looseness of the fabric is measured by the
count of the cloth. This is determined by the number of picks and
ends to the square inch.
 If the count of the cloth is 80 warps (ends) and 80 fillings (picks)
to the inch, the count is expressed as 80 x 80, or 80 square.
 If there are 60 warps and 50 fillings to the inch, the count is
expressed as 60 x 50.
 The count of surgical gauze is approximately 28 x 24.
 In comparison of the two counts, a 96 x 88 cloth is considered
the higher-count cloth because it has more ends and picks to the
square inch than has surgical gauze.

Weaving Technology II Emel

Önder/ Ömer Berkalp 4
 The proportion of warp yarns to filling yarns (picks) is called the
balance of a cloth.
 If the number of warps and the number of fillings to the inch are nearly
the same (not more than ten yarns difference), a cloth is said to have
good balance.
 The gingham (a stripe cotton cloth) whose count is 60 x 50 would be
considered a fair-balanced cloth.
 Gauze with a count of 28 x 24 also has a good balance.
 A sheeting with 61 warp ends and 40 picks (61 x 40) has poor balance
because there are too many ends and too few picks.
 Even though the sheeting is woven in the plain weave, ordinarily a
strong construction, there are so few picks that the ends will slip over
them very easily, causing a shredded effect.
 Good balance is very important in cloths that have to stand hard wear
and many washings. Sheets, pillow slips, and towels for glasses and
dishes, for instance, should have good balance.
Weaving Technology II Emel
Önder/ Ömer Berkalp 5
 Yarn Count System
(Fineness or coarseness of yarns)
It is very difficult to determine the yarn diameter by a
direct measurement and it is more common to express
the coarseness of the yarn in terms of its weight per unit
length, hence in terms of the yarn count.

1 Nm = 1,693 Ne = (1000/tex) = (9000/denier)

English Units
1 inch=2,54 cm ; 1 yard=0,91 m
1 libre(pound)=0,453 kg ; 1 ounce (oz.)=28,34 g

Weaving Technology II Emel

Önder/ Ömer Berkalp 6
 In practice, twist multiplier is
used to calculate the turns/inch
necessary for a given size spun
yarn.
 Twist multiplier is determined
from the turns per inch and the
cotton count:

where T = turns

 Typical twist multiplier range for S twist Z twist

cotton yarns is 2.5-5.

Burcak Karaguzel Kayaoglu 2011 7

 Open end (rotor) yarn
Cotton Ring spun yarn (wrapper fibers Air jet (vortex) spun
(helix angle of twist) perpendicular to yarn form) yarn
 The waviness of the yarn is
called “crimp”.
 Crimp has important effects on
the dimensions and performance
of the fabric.
 The existence of crimp means
that the lengths of filling or warp
yarn required are greater than
the width or length of the cloth.
 The basis weight of the fabric
(g/m2) depends on linear density
of the yarns used and total
length of the yarns assembled in Ref: Robinson, A.T.C., Woven Cloth Construction

the fabric.

Burcak Karaguzel Kayaoglu 2011 9

 As the weaving continues and
fabric gets away from the
reed, fabric starts narrowing
due to;
◦ Weave design
◦ Fabric construction (number of
warp and weft yarns/unit
length)
◦ Weaving tensions
 Interlacing pattern of the
weave design affects crimp Ref: Adanur, S., Handbook of Weaving

level in the fabric

 Crimp on the filling yarn
causes fabric to contract in
width direction.

Burcak Karaguzel Kayaoglu 2011 10

 (l)

(x)

 There are two alternative ways of defining crimp;

where l = length of yarn before crimping

x = length or width of the fabric
11
 Total warp and filling shrinkage includes weaving
crimp due to bending of yarns plus finishing
shrinkage.

Burcak Karaguzel Kayaoglu 2011 12

 Crimp is the waviness of warp and weft threads in
the fabric and expressed as a fraction. The crimp
(C),
 C= (yarn length – fabric length)/ fabric length

Crimp

c% = [(ly-lfab) / lfab] x 100

Take-up

k% = [(ly-lfab) / ly] x 100

Weaving Technology II Emel

Önder/ Ömer Berkalp 13
 Suppose 63 yards of warp are required to
produce a 60 yard piece of cloth.
 Then the warp take-up (contraction) =
[(63-60)/63]x100= 4.76 %
 The crimp=
[(63-60)/60]x100= 5 %

Weaving Technology II Emel

Önder/ Ömer Berkalp 14
 The fabric weight is expressed in  Basis weight:
grams per square meter (W/m²) or in
grams per meter of the fabric with full Used to compare different
width (W/m). fabrics.
 It is difficult to compare fabrics if the Related to end-use.
widths are not reasonably similar and Units: g/m2 ; oz/yd2
for this reason, weight per square
meter would be a more rational method
because differences in width would not  Fabric Weight per Linear Unit
affect comparison. Length
 The range of weights in woven fabric
varies from as little as 15 g per square  Used for trade (Buying or
meter for chiffon to 600 g or more per
square meter for heavy coating fabrics. Selling).
◦ suits- 350 to 500 and g/m2 Units: g/m ; oz/yd
◦ canvas and sacking cloth may be
1,000 or even 1,500 g/m2.

Weaving Technology II Emel

Önder/ Ömer Berkalp 15
 Fabric basis weight in g/m2
 There is a direct and simple quantitative relationship between fabric
weight and the other three structural parameters, namely, warp and weft
yarn counts, densities and crimps.

warp
1m
m2 Linear m

1m Fabric width

16
Burcak Karaguzel Kayaoglu 2011
Fabric Parameters

Comfort Tear Strength

Fabric End Use

Thickness Tensile
Fabric Properties

Thermal Abrasion

Fabric Weight
Fabric Weight Affects Fabric Properties / End Use
Weaving Technology II Emel
Önder/ Ömer Berkalp 17
 The cover defines the area of 1 cm² of a fabric which is
actually covered by warp and weft yarns. It is a useful and
practical indication of fabric’s permeability to light, air,
gasses, liquids and solid particles.

 Construction of a similar (of same cover) fabric to a cloth

with different construction parameters (yarn size, fiber etc.)

 Fabric cover is related to fabric properties (such as

passage of air and light). Thus designers can construct
fabrics with predetermined properties for certain end use.

Weaving Technology II Emel

Önder/ Ömer Berkalp 18
 Geometrical cover factor is a
function of “the extent to
which the superficial area
(surface area) is covered by
the component yarns”.
 It is the fraction of the area of
the cloth covered by the warp
or weft yarns.
 100% cover factor does not
mean that the fabric is
impermeable.
 Air can pass quiet readily
through interstices of the
weave.

Burcak Karaguzel Kayaoglu 2011 19

Cfab= Fabric Cover Factor = Total area of the cloth covered by warp
or weft yarns/ total area enclosed
d = yarn diameter (cm)
p = yarn spacing (cm)
d/p= measure of the relative closeness of the yarns in the warp
warp or weft of a woven fabric
Warpwise cover = C1= d1/p1 = d1 .n1
Fillingwise cover= C2= d2/p2 = d2 .n2

Cfab = C1+C2 - C1 C2

n1 = warp density/cm, n2= weft density/cm

20
Burcak Karaguzel Kayaoglu 2011
Cover Factor (Pierce): d/p
1
d (inch), n = yarn density/inch
28 Ne

d 1 1 n
x
p 28 Ne p 28 Ne

• Pierce multiplied the equation by 28 in order to eliminate the numeric

constant, 28, and expressed the result as ‘cover factor’, K .
Cover Factor= K= n/(Ne)1/2 , K = 28.c

warp cover factor K1 n1 n2

weft cover factor K2
Ne1 Ne2

21
Burcak Karaguzel Kayaoglu 2011
 Yarn Diameter Calculations
will be used for Cover Factor calculations...

tex 3 1
d 4,44 x x10 (cm) d (inch)
28 Ne

Grosberg Pierce

tex 3
d 3,57 x x10 (cm)

Monofilament yarn diameter =fiber density

22
Burcak Karaguzel Kayaoglu 2011
 d/p has a value of 1.0 when
yarns are just touching.
 Because Pierce multiplied by Cover factors
28, cover factor K= n/(Ne)1/2,
has a value of 28 when the
yarns are just touching.
 The relative yarn spacings
corresponding to various cover
factors are shown in figure.
 Cloth cover factor is the sum Ref: Robinson, A.T.C., Woven Cloth Construction

of warp and weft cover factors;

Kc = K1 + K2

Burcak Karaguzel Kayaoglu 2011 23

Ref: Lord, P.R.,Weaving: Conversion of Yarn to Fabric

Burcak Karaguzel Kayaoglu 2011 24

Fabric Cfab Kc
Structure
Open or loose 25% - 50% 7-14
structure
Regular 50% - 75% 14-21
structure
Close or tight 75% - 100% 21-28
structure

25
Burcak Karaguzel Kayaoglu 2011
 Fabric Thickness
Thickness is measured in millimeters. It is dependent on the yarn
diameters and on the degree of crimps of warp & weft yarns in the fabric.

 Fabric Width
Fabric width is usually expressed in cm.
It varies from 30 cm upwards.
Narrow fabrics like ribbons, tapes and braids are made by a special
section of weaving industry.
Certain types of fabrics are associated with specific widths.
Shirtings, pants & dress fabrics 145-155 cm etc.
Interlinings 70-90 cm
Worsteds and other suitings -150 cm
Bed sheetings, home textiles 2-3 m, etc.

 Piece Length
The piece length defines the piece of fabric cut to a particular length.

Weaving Technology II Emel

Önder/ Ömer Berkalp 26
 In strictly square plain weave cloth,
n1= n2, N1=N2, K1=K2 and C1=C2.

A section through square plain cloth

 In such a cloth, the sections
through the warp and weft are
identical.
 In this diagram threads are close
together as possible without
distortion of their circular cross-
section.
 For any combination of yarn type
and weave type, there is a
Ref: Robinson, A.T.C., Woven Cloth Construction
maximum number of yarns that
can be interlaced.

Burcak Karaguzel Kayaoglu 2011 27

 AC =1/2d+1/2d=d

 BC= 1/2d+d+1/2d=2d A section through square plain cloth

 AB= p= = 1.732d using

Pythagorean theorem.

 A thread spacing, p=1.732d

therefore represents the closest
possible theoretical spacing for a
square plain cloth.
 A cloth constructed to this rule would Ref: Robinson, A.T.C., Woven Cloth Construction

be said to have the “maximum

theoretical construction".

Burcak Karaguzel Kayaoglu 2011 28

 In a maximum ends x picks construction for a plain weave,
there are 1.732 yarn diameters of space required for one
yarn+interlacing.
 This is a theoretical distance, but it is useful in determining;
◦ The maximum interlacings or
◦ Maximum ends/cm and picks/cm and, therefore
◦ The maximum cover that fabric will have, given a certain yarn
count, of a plain weave fabric construction.

p = 1.732d
Burcak Karaguzel Kayaoglu 2011 29
 Given a 50/2 Ne ring spun yarn of 100% cotton in both
warp and filling, what are the max. ends and picks/cm that
can be woven into a balanced 2/1 twill fabric?

Ref: McCrieght, D. J., Weaver’s Handboof of Textile Calculations

Burcak Karaguzel Kayaoglu 2011 30

 At weaving, warp ends from warp beam are drawn through
drop wires, harness heddles, and through air spaces in a reed.
 The reed is identified by the number of dents per 10 cm.,
known as “reed number”.

Total ends in reed → total ends in the finished fabric

Fabric width → finished fabric width

31
Burcak Karaguzel Kayaoglu 2011
 Example:

 Warp density= 30 ends/cm

Finished fabric width:150 cm,
Total number of ends = 30x150= 4500 ends
Reed width= 177 cm
Reed Number = (4500 /177) x 10 = 255 or 128/2 (2 ends/dent)
=130/2

(Note: reed number is expressed as multiplies of 5)

Reed width = Finished fabric width (cm) x (1+%c2)

32
Burcak Karaguzel Kayaoglu 2011
Warp density: 30 ends/cm Weft density : 20 fillings/cm
Warp no: 24 tex Weft no: 30 tex
Warp crimp: 10% Weft crimp:8%
Fabric width: 150 cm

Determine;
Fabric basis weight in terms of g/m2 and g/m
(The required raw material to weave 500m of fabric in
kg)

33
Burcak Karaguzel Kayaoglu 2011
 1(1+c) = length of one weft yarn= 1,08 m (length of yarn before crimping)

1(1+c) = length of one warp

1 m = 100 cm

yarn= 1,1 m
length of yarn before crimping

1 m = 100 cm

Burcak Karaguzel Kayaoglu 2011 34

 Fabric basis weight (g/m2) = weight of warp yarns required
(g/m2) + weight of weft yarns required (g/m2)

Weight of warp yarns(g/m2)

Warp density: 30 ends/cm
Total number of ends in m2 = 30 ends/cm x 100 cm =3000 ends
Length of 1 end= (1+0,1)m = 1,1m
Total length of ends = 3000 x 1,1m x1m
Grams of warp yarn required = 3000x1,1 m x 24g/1000 m
= 79,2 ≈ 80 g/m2

35
Burcak Karaguzel Kayaoglu 2011
 Fabric basis weight (g/m2) = weight of warp yarns required
(g/m2) + weight of weft yarns required (g/m2)

Weight of weft yarns(g/m2)

Weft density: 20 fillings/cm
Total number of fillings in m2 = 20 x 100 cm = 2000 fillings
Length of 1 filling= (1 + 1,08) m = 1,08 m
Total length of fillings = 2000 x 1,08m x 1m
Grams of filling yarn required = (2000x 1,08 m x 30 g) /1000 m
= 64,8 g/m2

Total fabric basis weight = 80 + 64,8 = 144,8 g/m2

36
Burcak Karaguzel Kayaoglu 2011
 Total grams of yarn material required to produce 1.5m
full-width fabric (g/m) = Fabric basis weight (g/m2) x
fabric width(m)
= 144,8 g/m2 x 1,5 m
= 217,2 g/m
1m

m2 Linear m

1m Fabric width

37
Burcak Karaguzel Kayaoglu 2011
 Total grams of yarn material required to produce 1.5m full-
width, 500m length of fabric (g/m)
Grams of warp yarn required = 80 g/m2 x 750 m2
= 60.000 g = 60 kg
Grams of weft yarn required = 64,8 g/m2 x 750 m2

500 m
= 48.600 g
Area = 750 m2
= 48,6 kg

1,5 m
38
Burcak Karaguzel Kayaoglu 2011
 Given a 11,81 tex yarn of 100% cotton in both warp and filling, a
shirting fabric will be woven. Weave design is twill 2/1 Z.
a) What is the maximum theoretical fabric construction?
(or max. ends and picks per cm that can be woven into a
2/1 twill fabric? Create your own diagram for solution.

b) Determine warpwise and fillingwise fabric

1
cover factor, yarn diameter: d (inch).
28 Ne

c) Determine the fabric basis weight (g/m2).

(warp crimp= 6%, weft crimp=8%).

Burcak Karaguzel Kayaoglu 2011 39

 Given a Nm 50/2 worsted yarn in warp and a Nm 30/2 yarn in filling, a
finished fabric with a length of 100m and a width of 160 cm will be woven. A
warp beam with a reed width of 180 cm is prepared for weaving comprising
3600 ends of 110m in length. Weft density will be 16 fillings/cm on the loom.
a) Determine the warp and filling crimp.
b) Determine the reed number and ends/dent (based on yarn diameter).
c) Determine the fabric weight in g/m2 and g/m.
d) What is the maximum theoretical fabric construction for a
2/2 twill fabric? Create your own diagram for solution. Draw the weave
design, drawing-in-draft, reed plan and lifting plan diagrams.
e) Determine warpwise, fillingwise and total fabric cover and comment on
fabric structure.
f) Determine the kgs of warp and filling yarns required to produce 15.000 m
of finished fabric.

Burcak Karaguzel Kayaoglu 2011 40