# Friction Spinnig # Created By Abdullah Al Parvez , 9th batch , Department of Yarn Manufacturing , Chittagong Textile Engineering College ,Bangladesh

1. Friction
Spinning
Presented By :
Abdullah Al Parvez
Shurat Shahriar
Eti Sarkar
Jasim Munshi
Tamanna Akter Tomu

2. Abstract
• Friction Spinning or Dref Spinning is a textile technology that
suitable for spinning coarse counts of yarns and technical
corewrapped
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.

3. INTRODUCTION
• With the advent of modern spinning systems, frictional
properties of fiber assemblies have gained technical importance
because of the role played by inter-fiber 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

4. Features Of Friction Spinning
• Yarn properties: low tensile strength.
• 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.
• Good uniformity,high production rates.

5. Development of DREF
# 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

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. Basic Working Principle Of Friction (Dref)
Spinning
Fig.1-Individualizing of fibers on the drums
• The figure 1 describes the
DREF spinning principle
where the opened fibres
(1) made roll with an aid
of a mechanical roller (2)
for reassembling and
twisting.
• 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
directions in fig 2.

8. Fig.2- SchematicView of Friction Spinning

9. • 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).
• The surfaces at the nip of the two drums (4) move in opposite direction
to twist the fibres collected in the nip.
• The yarn is formed from inside outwards, by the superimposition of
twisting of individual
fibres.
• Therefore twists by fiber arrangement are generated.
• Due to separate yarn winding and method of twist insertion, it has
capability to go for high production rate.

10. • The twisting rate in friction spinning is related to the drum rpm, drum
diameter and yarn diameter as indicated below.
Twist (Count) = Drum Rpm x ( Drum Diameter ÷ Yarn Diameter ) x Twisting Efficiency
• 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

11. Types of DREF Friction Spinning :
1. DREF-1
2. DREF-2
3. DREF-3
4. DREF-5
5. DREF-2000
6. DREF-3000

12. Technological 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.A), where as DREF-2 has two friction drums (fig.B).
Fig.A-Dref-1 Schematic Fig. (Single Drum) Fig.B-Dref-2 Schematic Fig. (Double Drum)

13. 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.B)
• Outerwear and leisure-wear
• Filter cartridges for liquid filtration
• Secondary carpet backing for tufting carpets
• Canvas and tarpaulins for the military and civil sectors
• 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.

14.  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.C-Dref 3 ).
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Fig.C-Dref-3 Process Schema
 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.

15. DREF-1
• DREF-1 friction spinning system was developed in 1973
by Dr. Fehrer. A.G. of Austria.
• The fibers were opened with an opening roller and
allowed to fall on a single perforated cylindrical drum slot
• The rotation of the drum impart twist to fiber
assembly.
• The ratio of perforated drum to yarn surface is very
large, hence the drum speed can be kept relatively low.
• Due to the absence of positive control over the fibers
assembly, slippage occurred between the fiber assembly
and perforated roller, which reduced twist efficiency
• Hence this development could not be commercialized

16. DREF-2
•DREF-2 was exhibited in the year 1975 at ITMA exhibition.
•It operates on the basis of mechanical/aerodynamic spinning system with
an internal suction and same direction of drums rotation.
•Drafted slivers are opened into individual fibers by a rotating carding drum
covered with saw tooth type wire clothing.
•The individualized fibers are stripped off from the carding drum by
centrifugal force supported by an air stream from the blower.
•Fibers are transported into the nip of two perforated friction drums where
they are held by suction helping in the removal of dust and dirt thereby
contributing to production of cleaner yarn.
•The fibers are sub-sequentially twisted by mechanical friction on the
surface of the drums.
•The low yarn strength and the requirement of more number of fibers in
yarn cross-section (minimum 80-100 fibers) were restricted the DREF-2
spinning with coarser counts (0.3-6s Ne).
Fig : DREF-2 friction spinning system

17. Advantages of the core yarns produced using DREF-2 method
• Uniform breaking strength along the entire length and excellent running properties for
further processing (weaving and raschel knitting process).
• Excellent yarn regularity.
• Good adhesion of the sheath fibers to the core.
• No rewinding required due to the direct provision of the cylindrical bobbins to the weaving
process in a weight range of 8- 10 kg.
• Long, knot-free lengths.
• High weaving effectiveness, due to the eradication of thread breaks.
• High levels of area stability in the finished weave.
• Retention of a textile surface character.

18. DREF-2 Application and Fields
 Blankets for the home application range, hotels and military
uses etc.
 Interior decoration, wall coverings, draperies and filler yarn.
 Shoes, ropes and industrial cable manufacturing.
 Filler cartridge for liquid filtration
 For upholstery, table cloths, wall coverings, curtains, handmade
carpets, bed coverings and other decorative fabrics.
 Heavy flame-retardant fabrics, conveyor belts, clutches and brake linings,
friction linings for automobile industry, packets and gaskets.

19. DREF-3
• The DREF-3 machine is the next version of DREF-2 for improving
the yarn quality came to the market in the year 1981.
• Yarns up to 18s Ne. can be spun through this system.
• This is a core-sheath type spinning arrangement.
• The sheath fibers are attached to the core fibers by the false twist
generated by the rotating action of drums.
• Two drafting units are used in this system, one for the core fibers
and other for the sheath fibers.
• This system produces a variety of core-sheath type structures and
multi-component yarns, through selective combination and
placement of different materials in core and sheath.
• Delivery rate is about 300 m/min
Fig. Dref-3 Schematic Figure

20. DREF-3 Application and Fields
•Backing fabrics for printing, belt inserts, electrical insulation, hoses, filter fabrics
•Hot air filtration and wet filtration in food and sugar industries.
•Clutch lining and brake lining for automotive industries.
DREF-5
•It was developed by Schalafhorst, Suessen and Fehrer.
•The range of count to be spun from this system is from 16’s to 40’s Ne.
•Production speed is up to 200m/min.
•This spinning system was not commercialized due to some reasons.
•The individualized fibers from a single sliver are fed through a fiber duct
into the spinning nip at an angle to the yarn axis.
•They are stretched as far as possible, when fed into the nip.
Fig : DREF-5
Fig : DREF-3

21. Fig.D-Dref 2000
DREF-2000
•It is the latest development in friction spinning
demonstrated in ITMA 99.
•DREF-2000 employs a rotating carding drum for
opening the slivers into single fibers and a specially
designed system being used for sliver retention.
•The fibers stripped off from front the carding drum
by centrifugal force and carried into the nip of the
two perforated spinning drums.
•The fibers are subsequently twisted by mechanical
friction on the surface of the drums.
•Drums are rotates in the same direction.

22. Advantages of DREF-2000
• Insertion of twist in ‘S’ and ‘Z’ direction is possible without mechanical alterations to the
machine.
•Yarns up to 14.5s Ne can be produced at speeds of 250 m/min.
•Reduced yarn preparation costs due to high sliver weights (card slivers).
•Dust extraction for secondary fibers.
•Low energy costs due to the use of only 1 fan for 12 spinning heads.
•Feeding of all types of filaments, yarns and components as yarn cores, in order to attain high
yarn strength and production speeds, voluminous yarns and specific product characteristics.

23. DREF-2000 Application and Fields
•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
•Outerwear and leisure-wear
•Filter cartridges for liquid filtration
•Secondary carpet backing for tufting carpets
•Canvas and tarpaulins for the military and civil sectors
•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. DREF-3000
•In the ITMA 2003, the first public appearance of the DREF 3000 was made.
•The yarn can be spun form 0.3Ne to 14.5Ne.
Advantages of DREF-3000
•System Expansion of the scope of yarn and fiber utilization in the coarse yarn
count range
•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.

25. DREF-3000 Application and Fields
•High tenacity and FR protective clothing for civil & military sector
•Fire blocker for the aviation and contract business range, cut protection textiles
(protective gloves, mail-bags, seat coverings)
•Fiber composite materials for the aviation, automotive, machinery, and
construction industry
•Tarpaulins, transport and conveyor belts as well as all kinds of technical textiles
•Filter fabrics for dry and wet filtration
•Upholstery fabrics for contact business range
•Knitting sector, elastomeric fabrics
•Outdoor textiles (eg chair and dock-chair covering)

26. Mechanism of Yarn Formation
The mechanism of yarn formation is quite complicated.
It has three distinct operations, namely:
1. Feeding,
2. Integration and
3. Twist insertion of fibers.
Feeding:
The individualized fibres are transported by air currents and deposited in the spinning zone. There
is a definite effect of mode of feed on fibre extent and fibre configuration in yarn and on its
properties.
Fibre feed can be done in following methods.
• Direct feed
• Indirect feed.

27. 1) Direct feed
Fibers are fed directly onto the rotating fiber mass that outer part of the yarn tail.
2) Indirect feed
Fibers are first accumulated on the in-going roll and then transferred to the yarn
tail.

28. Fibers Integration
•The fibers through feed tube assembles onto a yarn core/tail within the shear field, is
provided by two rotating spinning drums and the yarn core is in between them.
•The shear causes sheath fibers to wrap around the yarn core.
•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 fibers
to the sheath.
Twist insertion
•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.

29. Twist insertion 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.
•However, it is quite possible for some amount of false twist to remain in the fact that the
sheath entraps it during yarn formation in the spinning zone.
Twist insertion in Open end 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 fibers in the yarn.
•The Figure shown the arrangement of fibers in the DREF-3 yarn as stacked cone shape .

30. 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.
•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.

31. 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:
A. For reinforced plastics
Properties of the yarn
• 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 filament through the sheath fibers
B. For liquid filter cartridges
Yarn Properties
• Huddle fiber arrangement for best filter action
•High elongation values
•Long yarn length knotless
•Uniform yarn with high tensile strength

32. C. For heat proof woven and knitted fabrics
Yarn properties
• Flame resistance
•High temperature resistance
•High tear abrasion resistance
•Good wearing comfort
•Good care properties
•Skin friendly
D. For Secondary carpet backings
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
•Electric insulation
•Good dimension stability for carpets

33. E. For asbestos substitutes
Yarn properties
• High yarn volume
•Good temperature resistance
•High tensile strength
•Low elongation
F. Cut proof woven and knitted fabrics
Yarn properties
• High cut resistance
•Good wearing comfort
•High dimension stability

34. Advantages of Friction spinning system
1.It can spin yarn at very high twist insertion rates (ie.3,00,000 twist/min).
2.The yarn tension is practically independent of speed and hence very high production
rates (up to 300 m/min) can be attainable.
3.Improved dirt particle retention and up to twice the filter service life.
4.Considerable reduced yarn production costs (up to 50%) due to lower yarn mass
requirement, lower preparation costs, lower spinning costs and lower personnel
expenses.

35. Limitations of Friction spinning system
1.The extent of disorientation and buckling of fibers are predominant with longer and
finer fibers.
2.Friction spun yarns have higher snarling tendency.
3.High air consumption leads to high power consumption.
4.The twist variation from surface to core is quite high; this is another reason for the low
yarn strength.
5.It is difficult to hold spinning conditions as constant.
6.The spinning system is limited by drafting and fiber transportation speeds.
7.Low yarn strength and extremely poor fiber orientation made the friction spun yarns
very weak.

36. Thank You
Slide Created By
Abdullah Al Parvez
9th Batch , Ctec
&
Moderated By Rest of the members .