yarn manufacturing 2

7/28/2019 Yarn Manufacturing 2

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YARNNUMBERINGSYSTEMYM - 2011


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COUNT

A specific number relative indicator of fineness or

linear density of yarn.

Yarn count is also called as yarn number.

Two main groups for its measurement: Indirect or reciprocal yarn numbering system

(higher number ~ fine yarn i.e., light in weight)

Direct yarn numbering system

(higher number ~ coarser yarn i.e., heavy in weight)

Usually staple spun yarns are defined by indirect

while direct system is used for synthetic filaments,

but exceptions are there


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INDIRECT YARN NUMBERING SYSTEM

Yarn number signifies the number of units of a

standard length that are necessary to balance one

unit of standard weight.

There are different yarn numbering standards

depending upon the system on which a staple yarn

is spun.

If yarn is spun on cotton system then cotton

numbering system (Ne) is used and if yarn spun on

worsted system then worsted number system (Nw)

is used, irrespective of fiber type used.


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INDIRECT YARN NUMBERING SYSTEM (CONT..)

Spinning

system

Standard length Standard

weight

Numbering

system

common name

Cotton 840 yards (yd) 1 pound (lb) Cotton or

English (Ne)

Woolen 1600 yards 1 pound Woolen run(Nar)

Woolen 300 yards 1 pound Woolen cut (Nar)

Worsted 560 yards 1 pound Worsted (Nw)

All 1000 meters (m) 1 kilogram (kg) Metric (Nm)

Cotton count (Ne) for single yarn is written as: #/1 or #s

Worsted count (Nw) for single is written as the reciprocal as: 1/#


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Yarn

number

ing

system

Length

of test

yarn

Weight

of test

yarn

Calculation using standard

for a count of 1 (Actual

Standard)

Yarn

number

Cotton 840 yd 1 lb 840 yd/lb 1 lb/840 yd = 1s Ne

Cotton 12600 yd 1 lb 12600 yd/lb 1 lb/840 yd = 15s Ne

Cotton 12600 yd 0.5 lb 12600 yd/0.5 lb 1 lb/840 yd

=

30s Ne

Woolen 1600 yd 1 lb 1600 yd/lb 1 lb/1600 yd = 1 Nar

Woolen 3200 yd 1 lb 3200 yd/lb

1 lb/1600 yd = 2 NarWorsted 560 yd 1 lb 560 yd/lb 1 lb/560 yd = 1/1 Nw

Worsted 1680 yd 1 lb 1680 yd/lb 1 lb/560 yd = 1/3 Nw

Metric 1000 m 1 kg 1000 m/kg 1 kg/1000 m = 1 Nm

Metric 20000 m 0.6 kg 2000 m/0.6kg 1 kg/1000 m

=

33.33

Nm


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Yarn

numbering

system

Count of yarn

to be twisted

Number of

strands (plies)

twisted

together

Yarn number

Cotton

20/1 or 20s 2 20/2

15/1 or 15s 3 15/3

15/3 2 15/3/2

Worsted

1/20 2 2/20

1/15 3 3/15

3/15 2 2/3/15


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DIRECT YARN NUMBERING SYSTEM

Yarn number signifies the number of units of

standard weight that are necessary to balance one

unit of standard length.

Indirect system used two different standards:

Tex

Denier Tex is recognized as world standard yarn

numbering system.


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DIRECT YARN NUMBERING SYSTEM (CONT)

Yarn numbering

system

Standard weight Standard length

Denier 1 gram (g) 9000 meters (m)

Tex 1 gram 1000 meters

Decitex (Grex) 1 gram 10000 meters


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DIRECT YARN NUMBERING SYSTEM (CONT...)

Yarn

number

ing

system

Weight

of test

yarn

Length

of test

yarn

Calculation using

standard for a count of 1

(Actual Standard)

Yarn

number

Denier 1 g 9000 m 1 g/9000 m 9000 m/g = 1 Denier

Denier 100 g 9000 m 100 g/9000 m 9000 m/g = 100

Denier

Denier 200 g 12000 m 200 g/12000 m 9000 m/g = 150

Denier

Tex 1 g 1000 m 1 g/1000 m 1000 m/g = 1 Tex

Tex 100 g 1000 m 100 g/1000 m 1000 m/g = 100 Tex

Tex 100 g 9000 m 100 g/9000 m 1000 m/g = 11.11 Tex

Tex 200 g 12000 m 200 g/12000 m 1000 m/g = 16.67 Tex


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INTER CONVERSION OF NUMBERING SYSTEM

Yarn

Number

System

Symbolic

Abbreviat

ion

Unit of

Length

Unit of

Mass

Unit of

Yarn

Count

Constant

for

Conversi

on to Tex

Values

CottonCount

Ne 840 yd 1 lb 840 yd/lb 590.5

Woolen

(cut)

Nac 300 yd 1 lb 300 yd/lb 1654.0

Worsted Nw 560 yd 1 lb 560 yd/lb 885.8

Metric Nm 1 km 1 kg 1 km/kg 1000.0

For example:


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INTER CONVERSION OF NUMBERING SYSTEM

Yarn

Number

System

Symbolic

Abbreviat

ion

Unit of

Length

Unit of

Mass

Unit of

Yarn

Count

Multiplyi

ng Factor

Yarn

Number

to Tex

Tex Tt 1000 m 1 g g/km ---

Denier D 9000 m 1 g g/9000 m 0.1111


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DRAFT

The reduction of weight per unit length is known as

draft.

The fiber strand between two pairs of rollers is

stretched due to difference in surface speeds of

both pairs. In roller drafting technique, the front pair

of roller always moves at a faster speed than the

back pair, therefore draft is defined as,

Draft =


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DRAFT (CONT)

As the surface speed of front roller is always

greater than the surface speed of back roller,

therefore draft is always greater than 1.

(if in any case, S.S of F.R = S.S of B.R, no drafting

will be achieved;

If, S.S of F.R < S.S of B.R, negative drafting will be

achieved and the material being drafted will get

accumulated in between the two pairs of rollers)


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TYPESOF DRAFT

There are two types of drafting;

i. Dispersion drafting

ii. Roller drafting


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I - DISPERSION DRAFTING

The type of drafting in which the material attains an

irregular and dispersed form is called dispersion

drafting.

Dispersion drafting mainly performs opening and

cleaning actions. Straightening and parallelization

are also observed but to a short extent.

Dispersion drafting takes place in blowroom, i.e.,

scutcher and card machine.


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II - ROLLER DRAFTING

The type of drafting in which a minimum of two

pairs of rollers are used to keep the material in a

regular form, is called roller drafting. E.g., the

regular form may be sliver, roving etc

Roller drafting mainly performs straightening and

parallelization of fibers. Opening and cleaning are

not usually concerned in roller drafting.

Roller drafting takes places on drawing frame,

simplex and ring spinning frame.

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