Spinners always endeavour
to achieve a very high standard of process efficiency and
product quality at the preparatory stages, ring shed and in
the cone winding department so that the final yarn package
delivered to the end-user meets his stated specifications
as well as performance criteria.
Modern automatic cone winding machines facilitate achievement
of these objectives of the spinners by extracting all disturbing
yarn faults and producing packages of constant length and
after paraffin waxing of the yarn if required.
However, the end-users also require guarantees from the spinners
that the packages delivered to them are free from ribboning
or patterning effect! Freedom from ribboning is an extremely
important requirement of the end-users because it confirms
that the yarn can be unwound from the packages smoothly at
high speeds and achievement of high standard of machine efficiencies
is possible during warping, weaving and knitting.
1. How is ribboning
or patterning produced?
Most of the present day automatic winding machines
incorporate grooved drums to traverse and wind the yarn
onto the package. Ribboning is difficult to avoid when
grooved drum is used. Suppose the drum shown in fig.
1 makes revolutions
per double traverse of the effective winding point and
revolves at (N) R.P.M. The package revolves at (n) R.P.M.
The diameters of the drum and the package are (D) and
Neglecting slippage between the package and the drum,
the surface speeds of the two should be equal, i.e.
PDN= Pdn or DN=nd -------------------(i)
Time taken by the drum for revolutions
per double traverse = minutes. During this time interval package
will rotate = / N
revolution now n/N can be substituted by D/d on the basis
of (i). Hence, during
the time interval for one
double traverse, the package will rotate times -----------------(ii)
i.e. number of revolutions of the package which will be equal
to the number of coils laid on the package per double traverse.
In the above & D equation
are constant during the formation of any package but (d) increases
continuously. Obviously there will be times when the number
of coils laid on the package will be a whole number. In such
situations coils of yarn will be wound one on top of the other
or very close to each other. Surface of such a package will
exhibit a ribboning or patterning effect leading to the following
. The density of the package will be uneven and therefore
unsatisfactory for dyeing purposes.
. The package will have poor unwinding properties. On unwinding
many coils will come off together i.e. slough off the package.
Sloughing off of the coils from the package is a source of
end-breakages in warping and weaving. In case of knitting
machines, this may damage the needles.
Thus, it is obvious that pattern or ribbon breaking mechanisms,
are an indispensable part of modern automatic winding machines.
All major manufacturers of winding machines have developed
`state of the art' machines, which include sophisticated devices
to prevent ribbon formation and facilitate production of ribbon-free
package. The operating principle and function of some of the
pattern/ribbon breaking devices is described as under:
2. Propack® system
Propack® is a new cradle anti-patterning system
incorporated by Schlafhorst in the automatic package
winding machine Autoconer 338 launched in 1997. The
entire product range has been available since ITMA Paris
in 1999. As already mentioned patterning occurs when
the number of coils laid on the package per double traverse
is a whole number. In other words, pattern zone is reached
when the ratio between drum speed and package speed
reaches a critical value.
The ratios between the drum and the package speeds are constantly
determined by the highly precise winding unit computer of
the propack system illustrated in Fig. 1.
As soon as the critical speed ratio which produces
patterning is about to reach the propack system reduces
the pressure on the cradle by a pre-determined amount.
Thus the package runs more slowly at a speed below the
critical patterning speed till the package diameter
is adjusted to a value above the pattern zone when the
propack® cradle anti-patterning system is turned
The anti-patterning effect achieved by the propack®
system is illustrated in Fig.2.
The propack® packages are recommended for use in
technologically demanding applications. The requirements
of standard applications can be met by packages, produced
on winding machines fitted with conventional electronic
The problem of yarn bulging out on the package flanks
is encountered in the case of winding elastic yarns
such as lycra yarns. This problem arises because yarn
is slightly tensioned during winding and tends to contract
back to its original position. The outer layers exert
pressure on the inner yarn layers which bulge out on
the package flanks. Such packages create problems in
subsequent processes of twisting and dyeing.
Schlafhorst has solved this problem by combining Autotense
and propack® systems in the Variopack FX system
for use in winding of elastic yarns. Some of the other
sophisticated devices, which make Autoconer 338 a state-of-the-art
machine, are ATT (Auto Torque Transmission), balloon
controller, Autospeed control system with thermo-sensor,
vacuum controlled suction plant with AVC system sensor
monitoring of the winding process with short piecing
Package without anti-patterning
extensive pattern zones and pronounced bands
Package with propack Elimination
of pattern zones
Source: Schlafhorst/Saurer Group
The superior performance of the Schlafhorst Autoconer 338
has been accepted in terms of quality of the wound package
and machine productivity world wide. There is an increasing
trend in the spinning sector of the textile industry of Pakistan
to replace the manual winding machines with Schlafhorst Autoconer
3. Semi-conductor device (TIRAC)
Semi-conductor device (TIRAC) is used on all models
of Muratec Mach Coner Automatic winder for pattern breaking.
The device is illustrated in Fig.3. Anti-patterning
effect is achieved by means of DIAL setting for ON and
OFF durations of the drum motor. Thus the speed change
cycle is adjusted. As the drum and therefore, the package
is constantly being accelerated and decelerated, the
ratios of their speeds never reach critical value to
On =0.5 to 2.0 Sec. Off = 0.5 to 2.5 Sec.
Source: Muratec technical leaflet
4. Double pitch drum
Muratec Mach Coner, introduced in 1979, has been completely
redesigned recently and is being marketed as Murata's new
generation process coner. The anti-patterning device has also
been redesigned. A new winding drum with two distinct pitches
on the same drum eliminates patterning (ribboning) and facilitates
high speed un-winding at the subsequent processes. Muratec
claims that package wound on the process coner meets the final
criterion of quality which is high speed unwinding property
in the ribbon critical zone. Some of the other new devices
incorporated in the new Murata Process Coner are Peral-A which
contributes to energy efficient operation, Perala-D which
reduces yarn hairiness, the
5. Anti-patterning modulation
"On-OFF" type electronic modulation is a regular
device incorporated in all models of Orion automatic winders
marketed by Savio. Drum and package speeds are constantly
adjusted so that the speed ratios do not reach critical values
and patterns on the package are minimised.
6. Computer Aided Package
C.A.P® is an electronic type modulation with computerised
control of the drum package diameter ratio. It is offered
as an optional device by Savio. It is claimed that with C.A.P®
Orion winders produce perfect packages with- out patterns.
Consequently, no unwinding speed limits are imposed in the
subsequent processes of warping, knitting and dyeing. Some
of the other devices which make Orion automatic winder, a
`state of the art' machine, are Inspector Control, Tensor,
Balloon Breaker, Booster (optional etc. The most prominent
feature is the positioning of the Electronic clearer as the
last device on the yarn path. Any long or moire defects are
detected by the clearer and eliminated being sucked from the
7. Precision winding
with counter-rotating blades:
Two counter-rotating blades are used on the SSM-PSM-51
Precision winder Fig.-4 (a) and 4 (b) for traversing
the yarn and deposit on the cylinderical package.
The blades rotate at constant speed and traverse the
yarn alternately to wind it on the package smoothly
The required density profile of the package is achieved
by correct choice of the wind ratio which remains constant.
The wind ratio prevents the number of coils per double
traverse reaching a whole number effectively from empty
to full package. Consequently no ribboning or patterning
is produced on the package. The crossing angle becomes
progressively narrower as the package diameter increases.
Fig. 4 (C). Some of the other advantages claimed for
precision wound packages are:
· 20% more yarn on the package as compared to random
· Better dye penetration, less yarn breakages in subsequent
processes, higher unwinding speeds are achievable.
· Packages can be used directly for dyeing without
In conclusion, it may be stated that the foregoing account
of the anti-patterning devices incorporated in their automatic
winding machines by the major winding machinery manufacturers
to produce ribbon-free packages is by no means exhaustive.
Hitherto, the predominent automatic winding machine in the
spinning sector of the textile industry of Pakistan has been
the Murata Mach Coner, followed by Savio Espero and Orion
winders. However, the latest trends is in favour of import,
installation and commissioning of the Schlafhorst Autoconer
338 as part of the BMR programmes of the spinning mills on
account of its overall superior performance.
Useful technical information received from M/s. Ahsan Bari,
Arsalan Zahid Piprani, Sheharyar Aslam Khan and Hasan Anas
(3rd year students) during the preparation of this paper is