Friction Spinning System

7/29/2019 Friction Spinning System

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Technical textiles belong to the most important material which will be used in the future . They

actually are already indispensable in automotive and space industry, in building and in medical

Fields. Also environmental protection and agriculture have demands which can only be satisfied

by technical textiles. Further, high performance protection garments, flame retardant textiles in

the contrect and transport sector, are gaining high importance and are the base of future

regulations in various highly industrialised countries. Today`s market situation leaves no doubt

about the economical importance of technical textiles : their sales rates are the mostly increasing.

Altogether, it is difficult to define accurately the meaning of technical textiles, as the

demarcation between technique and textile is literally fluctuating. Technical textiles are ranging

in the third place of average textiles production world - wide, together with the manufacture of

ready-made clothing and decorative fabrics with a share of 20-25 % .The production of technical

textiles is characterized by intensive research and development of fibers and composite

materials, as well as by the achievement of fibers for highly specialized application fields. This

supposes a continuous dialogue between producers and consumers, so that individual adequate

solutions can be proposed to individual specific problems.

There again, the Dref spinning technology asserted itself as one of

the most important alternatives in the field of high-tech and hybrid yarns. A manifest preference

for Dref yarn is show in many fields of application such as high - performance FR protection

garments for civil and military use, above all in the highest SA fire protection class, as well as in

flame retardant textiles for the contrect sector, space industry, composite materials for machinery

and automotive industry, filtration fabrics , non - asbestos textiles and many other technical

textiles . the demand for multicomponent yarns and core yarns is constantly growing. The

relatively costly cores are being replaced increasingly by such materials, such as stretch broken

aramids, carbon and other fibers . As sheathings it has proved possible to wrap almost any typeof staple around the structure, including synthetics and specialty fibers and even pure carded

cotton .

IN 1973 Dr Ernst Fehner invented the friction spinning system Dref . Friction spinning set a new

standard with its yarn delivery speeds of up to 250 m/ min. In addition to the high prod. Speeds

the unique features of the dref friction spinning are offering the possibility of the prod. Of tailor

made yarns in one operation. Especially the feeding of various types of cores and complete

covering of these cores have opened new fields of application for the dref friction spinning

technology.

DREF - 2

Based on the technical possibilities which are offered by this system for the coarse yarn count

range has been established on the market in 1977 as a serial machine. Since the first m/c sales

more than 1400 Dref 2 m/cs. Have been sold worldwide and the production rates in the coarse

yarn range of Nm 1 to Nm 10 are amounting to 318,000 tons of yarns. On the global yarn

production the coarse count range Dref 2 amounts to



35% to 40%.

DREF - 3

The second type of friction spinning technology being commercially sold is the Dref 3 friction

spinning process with its applications in the medium yarn count range.

The feeding of at least two fiber components-being necessary for the spinning principle of the

false twist fixation- results automatically in a

multicomponent yarn.

Just as one like it this basic idea can be extended to a multiple feed of sheath fibers , combined

the idea of the filament feed for the core.

The feeding of at least two fiber components-being necessary for the spinning principle of the

false twist fixation- results automatically in a

multicomponent yarn.

Just as one like it this basic idea can be extended to a multiple feed of sheath fibers , combined

the idea of the filament feed for the core.

In any case at correct choice of the material components between core and sheath the core

component is completely covered by the sheath This lads to the possibility of a selective, product

oriented marketing conception being far beyond the one for conventional yarns.

The DREF 3 yarn construction is charaterised by the core fibers located parallel as well as by the

second fiber component of an independent fiber source.

Through to the parallel location of core fibers , the yarn properties are similar to those of a ring

yarn and the strength is far higher than at the rotor yarns.

Besides the core component as stabilising element is enabling the high production

speeds of the Dref 3 friction spinning process.

The second fiber component of the yarn sheath being necessary on account of functioning

principle if offering the possibility - independently on the core component - to characteristise the

yarn optic,I.e. the final product.

Due to the procedure based on the core/

sheath structure the Dref 3 friction spinning process has the following fields of application :the

technical range , such as protection clothing for the automotive and high furnace industry;



fire fighters , technical fabrics, hot gas filtration , fire blockers and other FR-fabrics and friction

hybrid yarns for fiber materials reinforced by long fibers , where the yarns are embedded in a

thermoplastic matrix(for automobile and

aircraft industry).

The consequent utilisation of the core / sheath surface is forming the the main advantage of the

Dref 3 friction spinning process for the produced yarn and as a consequence for the product.

• DIRECTIONNS FOR THE USE:-

• For drafting unit 1

1 drafter sliver (regularity:max. c.v.5%)

sliver weight: 2,5 -3,5 K Tex

fineness 0,6- 3 denier

Stale length:

carded cotton(applicable only with filament)

synthetics: 40-60 m.m

Aramids, other special fibers:40-60m.m.

Stretch-broken slivers:up to max.140m.m.

No waste fibers

• DRAFTING UNIT 2 :-

• 5 Drafter slivers

• sliver weight:: 2,5 - 3,5 K Tex

• fineness : 0,6 - 3 denier

• STAPLE LENGTH:

carded cotton (portion of short fibers less than 12, 5 m.m. max. 10-15%),jute and other natural

fibers or blends thereof

synthetics : 40 -60 m.m.

Aramids and other special fiber;40-60m

no waste material.



• YARN COUNT RANGE :

Depending on the type of fiber,fineness as well as use of filament :

when using fibers of 40 -60 m.m length:

Nm 1,5-Nm30 (Ne0,9- Ne 18)

when using stretch broken slivers:

up to Nm40 (Ne 24)

3.USE OF RAW MATERIAL

Almost all kind of fibre material can be spun by this process, even those at that present problems

in other contexts, example aramid and carbon fibres .polyester and polyamide fibres are often

used in core and cotton in the envelop.

The proportion of envelop fibres can lie in the range 15-60%. Even filaments can be bound into

the core to give core yarns. The usable range of fibre linear density is from 0.6 to 3.3 dtex.

4. OPPREATING PRINCIPLE

This system produces bundled yarn according to the friction spinning principle .Basically, it is a

Dref - 2 process expanded to accommodate a drafting arrangement before the spinning drums .

A draw frame sliver with a linear density of 2.5 - 3.5 k Tex is passed into this three - line double- apron drafting arrangement.The strand resulting from the draft of about 100 - 150 proceeds

from the delivery of the drafting arrangement to the convergent region

between the two perforated drums .A pair of withdrawal rollers draws this strand through the

convergent region of the perforated drums and out of the spinning zone . The coherent fibre

strand is nipped at the withdrawal rollers and the drafting arrangement an d is rotated between

these points by a pair of perforated drums.It is therefore false - twisted between the nips.

The coherent fibre strand is nipped at the withdrawal rollers and the drafting arrangement an d is

rotated between these points by a pair of perforated drums.It is therefore false - twisted between

the nips.

This means that turns of twist are present between the drafting arrangement and the drums, but

not between the drums and the withdrawal rollers.

If this state of affairs were to continue,the strand would fall apart.Before this can happen, staple

fibres are fed in free flight from above onto the convergent region.



Owing to the rotation of the perforated drums, these in coming fibres wrap themselves around

the horizontally moving strand. A bundle yarn is formed.

The fibre cloud arriving from above issues from a second drafting arrangement with two opening

rollers. This arrangement is fed with from 4 to 6 draw frame slivers of linear density 2.5 to 3.5

Ktex.

From the with drawl roller ,the yarn passes to winding unit. The yarn normally leaves the

machine in the form of cross-wound packages.

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Friction Spinning System