SHREEE SHIVAJI EDUCATION SOCIETY ,AMARAWATI COLLEGE OF ENGINEERING &TECNOLOGY ,AKOLA KHADI 2010 “DEVELOPNENTS IN WEAVING” BY RAVI PUROHIT SURAJ PATIL ([email protected]) ([email protected]) FROM D.K.T.E SOCIETY’S OF TEXTILE & ENGG.INSTITUTE, ICHALKARANJI.416115 MAHARASTRA.
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motor , FDEI (Filling Detector at end of insertion, ELSY False selvedge device, and 32-
bit microprocessor.
New Multiphase weaving technology would be discussed in brief.
If our dream of enhancing number of shuttles machines in India is to be realized then theneed of the day would be the proper awareness of developments in machines, a criticalanalysis of technology for selection of machines, a through understanding of the
technology and suitable attitude for their operation, hence the first step, the developments
in these machines would be discussed in brief.
Introduction
The weaving is a process of formation of fabric with interlacement of two or more sets of yarns using a stable machine called loom. Human beings have started using the woven
fabrics since the drawn of history. If we exclude the Stone Age period, we may
conveniently say the history of civilization is also, to some extent, the history of weaving.Aitken says there is evidence that the Egyptians made woven fabrics over 6000 years
ago. Though primitive civilizations used coarser threads to make fabrics which were
crude and coarse, there are references of fine fabrics made from filament of silk in China.Silk was one of the most important products in China 4000 years ago. In India too, there
existed some of the finest hand woven fabrics. There are some references in Tamil
literature, that the great poet, Thiruvalluvar was a hand loom weaver.
Development of Handlooms
It is still not certain when the weaving process was introduced to human society. It is
clear from many historical records that weaving originated long before the time of JesusChrist. Except few activities else where, the major developments in textile took place in
England. In England the major shift from agriculture to woolen industry came in the 14thcentury. During all these years and a few hundred years after 14th century, the cloth was
produced on hand-looms which were not equipped with fly shuttle. Prior to Industrial
Revolution, a woven fabric was produced by at least two people employed on loom.
In 1733, John Kay invented the fly shuttle which enabled weft to be inserted morerapidly. John Kay, a weaver, further incorporated a mechanism with which, a weaver
could sit at the centre of the loom and merely pull the handle to make the shuttle move
from one end of the fabric to insert a weft thread.
As a result of increased weaving speed, the hand spinning method of yarn productioncould not meet the requirement of fly shuttle looms and subsequently the mechanical
spinning also developed rapidly in Britain with Hargreave's spinning Jenny (1770), Ark
Writh's spinning machine (1769) and cromption spinning mule (1779). The developmentof the mechanical spinning system induced further developments in the loom. Edmund
Cart Wright, an English clergy man, invented a so called powerloom which could be
Earlier version of powerloom was run by two men. Fortunately steam power was
available by 1765. Soon powerlooms were driven by steam and most of the wooden partswere replaced with iron. After the steam engine and cast iron in early 1800, great attention
was paid to increasing productivity of the machine. To help achieve the increase inproductivity, William Radeliffe patented a dressing frame in 1803 for sizing and drying the
warp threads prior to winding on to a weavers beam. Fast development in the loom took place and by 1821 there were over 50,000 looms in operation in some 32 mills in the north of
England. In just over 10 years from that date, the number had increased to some 1,00,000 and
the basic loom had almost developed to the machine we know today. Also between 1819 and1842 the average speed of the powerloom had increased from 60 to 140 picks per minute
with the rise on productivity, as a result England became world's richest industrial power.
A loom from the 1890s with a dobby head.
Developments in Automatic Loom
Traditional looms then were stopped every few minutes in order to replace the empty
weft pirns or cop in the shuttle and this limited the number of looms, a weaver could
operate to about four. James Northrop, an English man who emigrated to America andworked for the Draper Corporation, completed an automatic weft transfer system which
replaced the weft pirn in the shuttle without slowing or stopping the loom in 1889. This
mechanism enabled the weaver to tend 16 looms. The Northrop Automatic looms quicklycame to use in America, so that by 1930, 90% of the American looms were automatic
Similar developments took place elsewhere also, Ruti, a major loom maker of
Switzerland manufactured automatic bobbin changing Northrop loom in 1898. In Japan
also, Toyoda, Sakamoto, Tsudakoma, etc also developed shuttle looms with automaticweft transfer. After World War II, more productivity and efficiency were essential to
overcome increasing labor costs in Western countries. It was also realised that more
productivity is the key to reducing manufacturing costs of the loom. All attempts wereconcentrated to studying various factors affecting speed of the loom and the loom with
higher speed were made available.
Limitations of Shuttle Looms
Despite the relatively high speed and efficiencies in loom with conventional picking,
productivity of these machines will continue to be limited as long as their fundamentalconstructions involved the use of shuttle propulsion. Vincent has shown that the power
required for picking is proportional to the cube of the loom speed. If the loom speed is
increased from 200 to 300 picks per minute, the power requirement would increase by a
factor of (3/2)3 i.e. 3.4 times approximately. This results in following disadvantages
1. Greater strain imposed on the picking mechanism, thus rendering it liable to frequent
failure.
2. Greater amount of noise and vibration.
3. Because of superior energy in shuttle, greater strain is again imposed on the checkingmechanism.
4. The movement of shuttle will be more difficult to control and there will be a greater
possibility of its ejection from the loom.
The dynamic problems created by the picking and checking mechanism and the inherentprocess of pirn winding for shuttle looms had encouraged the loom makers to develop
alternative means of weft insertion in which heavy shuttle is not projected forwards and
backwards across the width of the loom. It is customary to refer these looms as shuttleless
looms. The various shuttleless looms that have been developed over a period of about 50years can be classified into various groups.
The emphasis on productivity and quality has developed the weaving technology very
much and as a result the working hours required to weave fabric from loom have been
reduced from about 20 to 0.25 during the last 125 years, and in the last 50 years there hasbeen a reduction of 95% in operative hours per standard unit produced. Majority of the
developments are taking place on the shuttleless looms in the following directions :
1. To increase productivity of the loom.
2. To make the looms more flexible for different kinds of fabric.3. To reduce the down time for changing style, etc.
4. Application of electronic control mechanisms to increase automation
5. Development of accessories such as dobby, jacquards, etc.
In addition to these, the newer looms are simple in design, the motions are more reliable,consumes less energy and have lower maintenance cost.
COMMON FEATURES IN ALL SHUTTLELESS MACHINES: -
Several essential features found common with all shuttleless machines are listed
below
Higher speed
Wider width.
Electronic take-up and let-off.
Shedding systems- cam, dobby and jacquard (mechanical and electronic).
Weft feeder threading is comparatively time consuming and, now the self-
threading by pneumatic system is done.
The weft cutter is electronically controlled and operated by steeper motor
By this, cutter can easily adapt to any cutting time to the accuracy of 1°. Style
changing time is saved.
with the help of mechanopneumatic tucking device can hold the weft at
both selvedges firmly during beating and then tuck-in. this eliminates auxiliary
selvedge and weft waste is zero. The system can work upto 850 rpm.
almost every machine manufacturer supplies positive easing motion for
maintaining constant tension during shedding and beating.
There is a new shedding concept introduced, in which the heald shaft is
directly controlled by Servo Motor. Thus the total motion of heald shaft can be
independently programmed.
DEVELOPMENTS IN RAPIER WEAVING: -
The Rapier machines are emerging as weaving machines of the future. They arenot far off from Airjet in production (Speed) rate (up to 1500mpm or 600 to 800 rpm)
without scarifying their special status of flexibility. They have been making inroads to
heavy fabrics (900 gsm) and also shedding off the known drawback of higher weft waste.
SPECIAL DEVELOPMENTS: -
The design improvement in Rapier gripper permits handling wide range of
yarns without any need for changes.
The machine owes its speed, flexibility and low energy consumption to a
combination of high technology and economic design. Style changes can be executed
‘Exceptionally rapidly’. Having independent motor drives, this yielded fewer moving
parts, fewer gears, fewer oil seals and no timing belts i.e. there are fewer elements to
The warp yarns pass over rotating weaving rotor and shed
forming elements select and lift warp yarn for shed formation. The curve shape of
the elements, rotation of rotor and movement of warp positioners help in selection
and formation of shed by controlling the motion of warp positioner. The weave
selection is made possible.
Weft insertion: -
The channel in the shed forming elements guide in insertion of
weft. The weft is inserted by nozzles are similar to Airjet weaving. Additional nozzlesbetween shed forming elements further support the weft. Four wefts are inserted at a
time. The weft measuring, clamping, cutting, sensing and controlling are similar to air jet
machines.
Beat-Up: -The combs located behind shed forming element perform the function
of conventional reed. The lower shed, which rises after insertion of weft, lift the weft
out of channel over the entire weaving width. The beat-up comb then catches the weft
and beats up.
The modular design concept adopted has helped to change warp beam within 20 min.
the warp beams up to 1600mm diameter can be used. The inclusion of batching
motion for cloth winding has reduced change intervals.Many machines are in operations since 1997- 98 and this might be the machine
for mass production in future.
CONCLUSION: -
Many times in the past it was argued that projectile and Rapier systems
have attained maximum speed limit. However, these machines continue to enhance
the speed limit and are not far behind Airjet machines. Most of the developments are
in the area of attaining better fabric quality, gentle treatment to warp and weft andreduced breakages. Another interesting trend is in the type of selvedge formation and
waste reduction. Weft waste has been reduced to zero even in Rapier and Airjet
machines.
The future trend in developments would, probably, be in similar lines.However, one cannot rule out some surprising, thrilling innovations like Sulzer