TE 550 NEW METHODS OF YARN

PRODUCTION
FRICTION SPINNING

1 SUBMITTED TO : PROF.DR.ALİ KİRECCİ

SUBMITTED BY: AYBALA ÖZCAN
DEPARTMENT: TEXTILE TECHN. BY
TEXTILE ENG.
ABSTRACT
 Friction Spinning or Dref Spinning is a textile technology that 
suitable for spinning coarse counts of yarns and technical core-
wrapped yarns.
  Dref yarns are bulky, with low tensile strength making them 
suitable for blankets and mop yarns, they can be spun 
from asbestos, carbon fibres and make filters was water 
systems.
 Yarns such as Rayon and Kevlar can be spun using this method.

 The technology was developed around 1975 by Dr. Ernst 
Fehrer.[1]
2
 INTRODUCTION
With the advent of modern spinning systems, frictional 
properties of fiber assemblies have gained technical importance 
because of the role played by interfiber friction.
Amongst the spinning systems, DREF provides a good platform 
for production of core spun yarns due its spinning principle.
 It offers less spinning tension to the core and core will be 
positioned exactly at the center of the yarn. 
Friction (DREF) spinning system is also known as an Open-end or 
Core sheath type of spinning system.

3
 FRICTION SPINNING

Features Of Friction Spinning

Yarn properties: low tensile strength

Good uniformity,high production rates

Application: yarns for knitting; terry yarns; weft yarns

Advantages: low manufacturing cost; possibility for automation; 
no fast-moving parts
Features: up now no limited application possibilities; delivery 
speed is independent from yarn count
Low energy expenses and low labor 
4
FRICTION SPINNING

According to development,the common form of characterizing 
the frictional properties of yarns and filaments is the coefficient 
of friction.

The coefficient of friction determines ;

                                                                - the surface properties, 
                                                                -the yarn 
                                                                -the fabric strength, 

5
 FRICTION SPINNING
Development of DREF core-spun yarns unveils a path for new 
products including ,

• high performance textiles, sewing threads and in the apparels
•due to its exceptional strength, outstanding abrasion 
resistance, consistence performance in sewing operation, 
•adequate elasticity for the stretch requirements,
•excellent resistance to perspiration, 
•ideal wash  and wear performance and permanent press.
6
Principle Of Friction (DREF) Spinning Systems

     The friction spinning system consists of;

 opening & individualization of fibres from slivers,

 reassembling of individualized fibres ( collecting),
 
twisting (imparting the strength by twisting),

withdrawing newly yarn formation,

winding of yarn. ( a cross-wound package)
7
 SCHEMATIC VIEW OF FRICTION SPINNING SYSTEM

Following
process line

Fig.1-SchematicView of Friction Spinning

 Basic Working Principle Of Friction (Dref) Spinning

1-opened
fibers
 The figure 2 describes the 
DREF spinning principle 
where the opened fibres 
(1) made roll with an aid 
2-roller of a mechanical roller (2) 
for reassembling and 
3-rotating drums
twisting.
Fig.2-Individualizing of fibers on the drums

 Fibers  are  delivered  onto  the  drum  surface  (3),  which 

transports  and  stacks  the  fibers  to  the  fiber  bundle 
rotating  between  two  surfaces  moving  in  opposite  9
directions in fig.1.
Basic Working Principle of Friction (DREF) Spinning 
Fig.1-SchematicView of Friction Spinning

Collected drums

2
3

•  Friction spinning uses two friction surfaces to roll up fibres into a yarn.
• The fibres flow freely to two rotating friction drums (3) (spinning 
drums, friction rollers, torque rollers).  10
• The surfaces at the nip of the two drums (4) move in opposite direction 
to twist the fibres collected in the nip. 
 Basic Working Principle of Friction Spinning
Collected drums
4 •   The yarn is formed 
from inside outwards, 
by the superimposition 
of twisting of individual 
fibres.

• Therefore twists by 
fiber arrangement are 
generated.

Following • Due to separate yarn 
process line winding and method of 
twist insertion, it has 
capability to go for high 
Fig.1-SchematicView of Friction Spinning production rate. 11
 Basic Working Principle of Friction Spinning
 The twisting rate in friction spinning is related to the drum rpm, drum
diameter and yarn diameter as indicated below.

 Because of the very large ratio between the drum and yarn diameters,
the rotational speed of the drums need not be high, provided adequate
twist efficiency is achieved.

 The twist efficiency is reduced due to the slippage between the yarn in
the nip and the drum surfaces. It is possible to have a twist efficiency as
low as 40%. But even allowing for this, friction spinning is still the most
efficient way of inserting twist to fibres, because twist is directly applied
to yarn end. 12
YARN FORMATİON İN FRİCTİON
SPİNNİNG SYSTEM

The mechanism of yarn formation is quite complex. It

consists of three distinct operations, namely:

Feeding of fibers,
Fibers integration

Twist insertion.

13
 YARN FORMATİON İN FRİCTİON SPİNNİNG
SYSTEM

 1-FEEDING
The individualized fibers are transported by air currents
and deposited in the spinning zone.

The mode of fiber feed has a definite effect on fiber extent

and fiber configuration in yarn and on its properties.
There are two methods of fibre feed :

a)Direct feed
b)Indirect feed. 14
YARN FORMATİON İN FRİCTİON SPİNNİNG SYSTEM
 FEEDING
In case of direct feed, fibers are fed directly (b) or forward guidance onto the
rotating fiber mass that outer part of the yarn tail.
In indirect feed (c ) or bacward guidance, fibers are first accumulated on the in-
going roll and then transferred to the yarn tail. Figure 3 (b) and (c) are
showing the above methods of fiber feed.

15
Fig.3-Direct and Indirect Fiber Feeding Methods
YARN FORMATİON İN FRİCTİON SPİNNİNG
SYSTEM

 2-FIBERS INTEGRATION:

The fiber orientation is highly dependent on the decelerating

fibers arriving at the assembly point through the turbulent
flow.
The fibers in the friction drum have two probable methods for
integration of incoming fibres to the sheath.
 One method, the fiber assembles completely on to
perforated drum before their transfer to the rotating sheath.
 In the other method, fibers are laid directly on to rotating
16
sheath.
 YARN FORMATİON İN FRİCTİON SPİNNİNG
SYSTEM

 3-TWIST INSERTION:

In friction spinning, the fibers are applied twist with more or

less one at a time without cyclic differentials in tension in
the twisting zone.

Therefore, fiber migration may not take place in friction spun

yarns.
The mechanism of twist insertion for core type friction
spinning and open end friction spinning are different,which 17
are described next slayt.
YARN FORMATİON İN FRİCTİON SPİNNİNG
SYSTEM
 TWIST INSERTION:

a-In Core Type Friction Spinning

 Core is made of a filament or a bundle of staple fibers is false
twisted by the spinning drum.
 The sheath fibers are deposited on the false twisted core
surface and are wrapped helically over the core with varying
helix angles.
 It is believed that the false twist in the core gets removed
once the yarn is emerged from the spinning drums, so that
this yarn has virtually twist less core. 18
YARN FORMATİON İN FRİCTİON SPİNNİNG
SYSTEM
 TWIST INSERTION:

b-In Open End Type Friction Spinning

 The fibers in the yarn are integrated as stacked cone.

 The fibers in the surface of the yarn found more compact and
good packing density than the axial fibres in the yarn.
 The Figure 4 shown the arrangement of fibers in the DREF-3 yarn
as stacked cone shape .

19
 COMPARE WITH RING SPINNING AND ROTOR
SPINNING..
 Unlike ring spinning and rotor spinning, friction spinning
imposes very little tension to the yarn.
 So the ends-down rate in friction spinning is very low and the
yarn can be withdrawn from the nip of the drums at a very
high speed, say 300 m/min. This makes friction spinning
more productive than ring and rotor spinning.
 Similar to rotor spinning, friction spinning uses sliver feed
and tooth drafting.

20
DEVELOPMENT CATEGORİES OF FRİCTİON
SPİNNİNG
 DREF-1
 DREF-2
 DREF-3
 DREF-5
 DREF-2000
 DREF-3000

21
TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM
 ‘Dref’ is the trade name given to the machine based on friction spinning
system, which was developed by Dr E Fehrer of Austria. This process is
primarily suited to spin coarser and recycled yarns but most suitable to spin
technical yarn. Today, Dref is only spinning machine, which got commercial
success.
 The different versions of the machine are DREF-1, DREF-2, DREF-3, DREF-
5, DREF-2000 and DREF-3000. DREF-1 friction spinning system has single
friction drum (fig.5), where as DREF-2 has two friction drums (fig.6).

22

Fig.5-Dref-1Schematic Fig. (Single Drum) Fig.6-Dref-2 Schematic Fig. (Double Drum)

 TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM
 Dref-2 is one of the earliest friction spinning machines introduced in the market
somewhere around 1977 primarily for long staple fibers to produce coarser yarns
was exhibited in the year 1975 at ITMA exhibition.
 Dr Ernst Fehrer began work on the development of the DREF 3 friction spinning
system, which was first presented to the public at the 1979 international textile
machinery exhibition (ITMA'79) in Hanover.
 Dref-3 is a development over of Dref-2 system for improving the quality of
yarn,productivity and count range came to the market in the year 1981,and this is a
core-sheath type spinning arrangement and produce component yarns which can
not be produce by other spinning machines(Fig.7-Dref 3 ).

Fig.7-Dref-3 Process
Schema

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Technological Developments Of Dref System
Dref -2 End-Uses Areas

Blankets for the homes, hotels, hospitals, camping, military uses, plaids etc.
Cleaning rags and mops from cotton waster and various waste-blends
Deco- and upholstery fabrics (fig.8)
Outerwear and leisure-wear
Filter cartridges for liquid filtration
Secondary carpet backing for tufting carpets
Canvas and tarpaulins for the military and civil sectors Fif.8-upholstery fabrics
High-tenacity core yarn for ropes, transport and conveyor belts
Asbestos substitutes for heavy protective clothing (protective gloves, aprons
etc) packing, gaskets, clutch and brake-linings, flame retardant fabrics etc.
Filter yarns for the cable, shoe and carpet industries
Carpet Yarns (Berber carpets, hand-woven and hand-knotted carpets) and filler
weft yarns for carpets.
24
TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM
 Dref 5 was developed by
Schalafhorst, Suessen and Fehrer
after Dref 3,but this spinning
system was not commercialized
due to to various technical
difficulties.
 In 1999 ,Dref 2000 was

demonstrated at ITMA exhibition

(fig.9).
 It has ‘S’ and ‘Z’ direction is

possible without mechanical

alterations to the machine.And this
Fig.9-Dref 2000
machine also has dust extraction 25
for secondary fibers and low
energy costs due to the use of only
TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM

Dref-3 spinning system has

advantages over Dref-2 which
are;
oThe sheath fibers are attached
to the core fibers by the false
twist generated by the rotating
action of drums.[fig.10]
oTwo drafting units are used in
this system, one for the core
fibers and other for the sheath
fibers

26
Fig.10-Dref-3 Schematic Figure
TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM
Dref 2000 End-Uses Areas

Blankets for the homes, hotels, hospitals, camping,

military uses, plaids etc.
Deco- and upholstery fabrics
Outerwear and leisure-wear
Filter cartridges for liquid filtration
Secondary carpet backing for tufting carpets (fig.11)
Fig.11-Dref 2000 end
Canvas and tarpaulins for the military and civil sectors
uses,Gloves and
High-tenacity core yarn for ropes, transport and secondary carpet
backing yarns,TBA
conveyor belts Textiles
Asbestos substitutes for heavy protective clothing
(protective gloves, aprons etc) packing, gaskets, clutch
and brake-linings, flame retardant fabrics etc.
Filter Yarns for the cable, shoe and carpet industries
Carpet Yarns (Berber carpets, hand-woven and hand- 27
knotted carpets) and filler weft yarns for carpets. (fig.9)
TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM

 The latest innovation of

spinning system is
exhibited in the ITMA
2003, the first public
appearance of the DREF
3000 was made. Higher
bobbin weights through
200 mm winding traverse
was used (fig.12).
 Apart from other dref
types,in Dref 3000,the
drafting unit can handle all
types of synthetic fibres.
28

Fig.12- Dref 3000

 TECHNOLOGİCAL DEVELOPMENTS OF DREF
SYSTEM

Dref 3000 End UsesArea

Backing fabrics for printing, electrical

insulation, hoses, filter fabrics
Hot air filtration and wet filtration in food
and sugar industries.
Clutch lining and brake lining for
automotive industries.(fig.13)
Fire resistant protecting clothing,aircraft
and contract carpeting, Fig.13-Brake linings for
auotomotive industry produced
Conveyor and transport belts. by Dref 3000 method.

Composites for aviaton and automotive

29
industries.
TECHNOLOGİCAL DEVELOPMENTS OF
DREF SYSTEM
Dref 3000 spinning system has a drafting unit can handle all types of synthetic
fibres such as;
aramid, FR and pre-oxidized fibres, polyamides, glass fibers in blends

phenol resin fibres (e.g. Kynol), melamine fibres (e.g. Basofil), melt fibres (e.g.
PA, PES, PP),
natural fibres (wool, cotton, jute, linen, flax, etc.),

Dref 3000 has some advantages over other friction systems ;

Production of both ‘S’ and ‘Z’ yarns at any time without mechanical
alterations to the machine.
Reduced yarn preparation costs due to high sliver weights (card slivers)

Higher Bobbin weights through 200mm winding traverse.

DREF 3000 core yarns offer high output, breakage-free spinning and weaving
mill operation and thus up to 95% efficiency can be achieved.
30
SPINNING TENSION FOR DREF YARNS
 Friction spun yarns have less spinning tension during the yarn
formation.(Fig.14)
 Due to less tension during the spinning the core component can be
placed exactly at the centre of the yarn.

31
Fig.14-Spinning Tension for DREF Ring and Rotor Yarns
PROPERTIES OF FRICTION SPUN YARNS

 Friction spun yarns (DREF) yarns have bulky appearance (100-140%

bulkier than the ring spun yarns).

 The twist is not uniform and found with loopy yarn surface.

 Usually weak as compared to other yarns.

 The yarns possess only 60% of the tenacity of ring-spun yarns and
about 90% of rotor spun-yarns.

 The breaking elongation of ring, rotor and friction spun yarns is equal.
32
PROPERTİES OF FRİCTİON SPUN YARNS
 Depending on the type of fiber, the differences in strength of these
yarns differ in magnitude.
 100% polyester yarns-strength deficiency is 32%
 100% viscose yarns-it ranges from 0-25%
 In polyester-cotton blend, DREF yarns perform better than their ring-
spun counterparts.
 70/30% blend yarn-superior in strength by 25%
 DREF yarns are inferior in terms of unevenness, imperfections,
strength variability and hairiness.
 The friction spun yarns are more hairy than the ring spun yarns
 DREF yarns are most irregular in terms of twist and linear density
while ring spun yarns are most even.
33
PROPERTIES OF HYBRID YARNS/DREF CORE
YARNS
If one yarn creates out of 2 or more single
yarn components is called hybrid yarn.
Hybrid yarns are used;
 For reinforced plastic (fig.15)

Yarn Properties
 Core/Sheath structure with

centric position of the reinforcing

filament
 Zero twisted reinforced filament

gives best strength result

 Definable fiber matrix proportion

 Protection of the reinforcing Fig.15-Reinforced plastics

produced by dref method used
filament through the sheath hybrid yarn 34
fibers
HYBRİD YARNS/DREF CORE YARNS
 For liquid filter cartridges (fig.16)
Yarn Properties
 Huddle fiber arrangement for best filter action

 High elongation values

 Long yarn length knotless

 Uniform yarn with high tensile strength

 For heat proof woven and knitted fabrics (fig.17)

Yarn properties
 Flame resistance Fig.16-Liquid filter cartridges
 High temperature resistance

 High tear abrasion resistance

 Good wearing comfort Fig.17-Fire gloves

 Good care properties
,nonflammable
woven hybrid fabric
 Skin friendly produce by friction
method.. 35
HYBRİD YARNS/DREF CORE YARNS

 For Secondary carpet backings(fig.18)

Yarn Properties
 Steady high tensile strength

 High uniformity of the yarn

 Long knotless length of the yarn

 Good non-rotating properties

 High chemical resistance

 Good thermal transfer

 Dust free product Fig.18-Secondary backing

fabric of tufted carpet.
 Electric insulation

 Good dimension stability for carpets 36

HYBRİD YARNS/DREF CORE YARNS
 For asbestos substitute (fig.19)
Yarn properties
 High yarn volume

 Good temperature resistance

 High tensile strength

 Low elongation

 Cut proof woven and knitted fabric Fig.19-Ropes and Fabrics which are
used marine produces by asbestos
(fig.20) by frictipn method.

Yarn properties
 High cut resistance
Fig.20-Cut –roof gloves
 Good wearing comfort

 High dimension stability

37
ADVANTAGES OF FRICTION SPINNING
SYSTEM
 Greater flexibility of processing a wide range of fibres.
 Higher production speed (up to 500 mpm).

 Ability to produce multi component and hollow yarns.

 Ability to generate huge no of turns per unit length of yarn

with one revolution of twisting element.
 The number of end-breaks in friction spinning is quite low,
which results in higher machine efficiency than ring and rotor
spinning.
 Rewinding is eliminated.

 Bulkier and softer handle than that of ring and rotor spun yarn
38
LIMITATIONS OF FRICTION SPINNING SYSTEM
 Low yarn strength and extremely poor fiber orientation made the
friction spun yarns very weak.
 The extent of disorientation and buckling of fibers are predominant
with longer and finer fibers.
 Friction spun yarns have higher snarling tendency.
 High air consumption leads to high power consumption.
 The twist variation from surface to core is quite high; this is another
reason for the low yarn strength.
 It is difficult to hold spinning conditions as constant.
 The spinning system is limited by drafting and fiber transportation
speeds.
39
 İN COMPARİSİON WİTH OTHER SPİNNİNG
SYSTEMS
 Friction spun yarns are usually weaker than other yarns due its structural
weakness. It has been demonstrated that DREF-2 friction spun yarns possess
only 60% of the tenacity of ring spun yarns and about 90% of that of rotor
spun yarn.
 It has also shown that friction spun yarn generally has

*60 - 70% strength,

*60 - 90% unevenness,
*100 - 140% bulk and
*requires 75 - 100% of the minimum no of fibres
in the cross section as compared with the corresponding ring spun yarn.
 Rotor spun yarns show the highest evenness followed by ring spun and
friction spun yarns.
 The imperfections were also less in friction spun yarns than in rotor spun
yarns but higher than those in ring spun yarns. 40
İN COMPARİSİON WİTH OTHER SPİNNİNG
SYSTEMS
 Further friction spun yarns are more hairy than ring or rotor yarns and are
more susceptible to stripping back and thus abrading easily.
 In respect of yarn to metal friction, ring spun yarn exhibits the highest
friction, followed by rotor and friction spun yarns for cotton and viscose
fibres. With polyester fibre, friction spun yarns show the highest value of
friction followed by rotor and ring spun yarns.
 DREF-3 yarns occupy an intermediate position between ring and rotor
spun yarns as far as short hair (up to 3 mm) and total hairiness were
concerned.
 In addition DREF-3 yarns are the most irregular in terms of twist and
linear density unevenness, and ring spun yarns are most even.
 DREF-3 yarns also show a lower resistance to abrasion and repeated
extensions than ring and rotor spun yarns.
 Further the twist level did not have any influence on the rigidity of ring
and rotor spun yarns. But the flexural rigidity of DREF-3 yarns decreased41
considerably with increasing twist.
 REFEFERENCES
1-Wang X, Huang W and Huang XB, 1999, A study on the formation of yarn hairiness,
Journal of the Textile Institute, 90 Part 1, No 4, p.555 - 569.
2-Grosberg, P. and Iype, C., Yarn production - Theoretical aspects, The Textile Institute,
Manchester, 1999.
3-Klein, W., Manual of textile technology Vol 5: New spinning systems, The Textile
Institute, Manchester, 1993, p.14.
4-Wulfhorst, B., Evaluation of the new spinning techniques on automation and quality
criteria, ITB - Yarn Forming, No. 4, 1990, p. 5 - 13.
5-http://textlnfo.wordpress.com/2011/11/12/dref-spinning/
6- http://textile2technology.com/2009/10/dref-3-yarn-frictional-behaviour.html
7-Friction Spinning-A Critical View ,N.Balasubramanian,The Bombay Research Textile
Association,L.B.S Marg,Ghatkopar (West),Bombay 400 088,13 April 1992.
8-Experimental Study of the Frictional Properties of Friction Spun Yarns, S. S.
Ramkumar,* L. Shastri, R. W. Tock, D. C. Shelly, M. L. Smith, S. Padmanabhan,Texas Tech
University, Lubbock, Texass,29 August 2002.
42
9- http://www.indiantextilejournal.com/articles/FAdetails.asp?id=4636