Technology of Denim
Production: Part – III
(Long Chain Beamer & Sizing
Techniques for Denim)
Technology of Denim Production: Part – III
(Long Chain Beamer & Sizing Techniques for Denim)
By: Supriya Pal
Long Chain Beamer
After the rope dyeing of warp yarn in denim production, the next operation is the Long Chain
Beamer (LCB). When the rope has been dyed and dried in the rope dyeing range, it is taken in
large cans in coiler section. In rope dyeing range, if the machine has a capacity 24 ropes, then
there will be 24 separate coilers which delivers 24 ropes in separate cans. These cans are
transferred to the Long Chain Beaming area. The basic purpose of long chain beamer is to open
the rope into a sheet form of yarn and wind onto a warper beam which in turn transferred to the
Fig. 1: Long Chain Beamer
In Long Chain Beamer, the yarn alignment in the dyed rope is change from a rope form to a
sheet form. In the Long Chain Beamer the rope pull from the can ( Fig. 2) by moving them
upward to a guiding device. The guiding device is mounted above the can, probably in the
ceiling. The upward movement of the rope allows the ropes to untangle before nearing the
beamer head and allow the rope to shake loose form from the rest of the rope in the can.
When the ropes come down from the guiding device, it passes through tensioning Stand rollers
(Fig. 3). The purpose of the Tension rollers is to established necessary warp tension to the rope
and help in further separation of the ropes before going through a comb. If no tension is applied
to the rope, then the rope have a tendency to resist opening up into the sheet form. Ultimately
each in the rope will start separating directly at the comb located at the Long Chain Beamer.
This may leads to rope damage.
The Tension Stand is approximately 4-feet high and consists of two tension drums, each
approximately 14-inches in diameter and 14 inches face length. These rolls are fitted one over
Before passing through the Tension Stand, the rope passed through a simple pretension device,
which is located at the base of the Tension Stand. The pretension device applied slight
resistance to the rope before wrapped onto the tension rolls which is located on this Tension
Fig. 2: Passage of dyed yarn rope in Long Chain Beamer
Two large rolls are mounted on the Tension Stand. These rolls are mechanically geared
together. One of the roll is connected to either an EDDY Current Brake or an Air over Oil Disk
Brake. The rope is wrapped around these two rolls 4 to 5 times, which prevents the rope from
slipping on the surface of the rolls. Tension roll stand design is such that, it allows the yarn to
naturally wind around the tension rolls. This eliminates rolling in the rope due to screw effect of
rope guide rods on other tension stands.
Fig. 3: Tension Stand
Some machinery manufacturer incorporates an AC Vector motor and drive is used to create
tension in the rope instead of a pneumatic or EDDY current brake. This provides considerable
energy saving. As the motor is operated in a regeneration mode, it providing power that can be
consumed in the beamer head.
The rope from the tension stand passes through an Accumulator.
Fig. 4: Passage of dyed yarn rope in a Typical Long Chain Beamer
An accumulator is a device which allows the rope to be accumulated in a controlled manner at
the time of unwind the section beam on the Long Chain Beamer in order to find out and to repair
a broken end. The accumulator is an important component on a Long Chain Beamer, as there
is no stop motion device in the re-beamer and the operator observes the yarn sheet whether
there is any broken end. Accumulator may be of different types, such as:
Open Sheet Accumulator: This type of accumulator accumulated the yarn in sheet
form. It is normally mounted behind the comb of the LCB machine and accumulates
upwards. In normal condition, the yarn sheet passes between two overlapping rolls. The
top rolls fixed, whereas the bottom roll is fitted on sprockets. At the time of an end
breakage, the beam drive is reversed and the bottom roll is raised. Hence the yarn sheet
is raised along with the roll. After repairing the broken end, the beam drive is changed to
its normal mode and the bottom roll on the accumulator is lowered back to its normal
position. This type of accumulator is inexpensive. However, there is a chance of chain
slipping off of the sprocket during accumulation.
Offset Roll Rope Accumulator: This type of accumulator is fitted behind the LCB
headstock and in front of the Tension Stand. Two sets of cantilevered rollers are used,
one set of which is mounted above the other. The rollers are arranged in such a manner,
so that the top rollers are offset in position relative to the bottom rollers. Under normal
working condition, the rope passes through a gap between the top and bottom rollers.
The top set rollers are movable, whereas the bottom set are fixed. At the time of an end
breaks, the top rolls are brought down between the lower rolls. As the rope is placed
between the top and the bottom rollers, it also pulled down and accumulated with the
rollers. When the end is repaired, the top rollers is brought back to its normal position.
Deep Groove Pulley Rope Accumulator: This type of accumulator also fitted between
the LCB head stock and the Tension Stand. The accumulator consists of two sets of
high polished deep dish pulley. Four of these pulleys are fixed to the accumulator body.
Three of them are attached to Tol-Of-Matic pneumatic cylinders which are fixed to a long
rail. The location of the pulleys on the housing are offset from the ones the cylinders.
Even in normal working condition, the rope is engaged to the pulleys. At the time of an
end breakage, the beam drive is reversed by the operator. The pulleys attached to the
cylinders moves away from those mounted on the housing, which results in
accumulation of ropes in the accumulator.
Beater Bar and Comb
After the Accumulator the rope returns to the Tension Stand. There is a Beater Bar located at
the top of the Tension Stand which is round four or five sided in shape. It is at this point where
the yarn rope begins to be opened into a yarn sheet. The function of the Beater Bar is to apply
sufficient tension, friction to the rope, assisting in the opening or spreading the yarn and to
separate the ends without any damage to the yarn. After the Beater Bar the rope passes
through a comb located on the Long Chain Beamer, which separates individual yarn ends and
keeps them parallel to one another. From the comb, the warp yarns are guided onto a flanged
In the Long Chain Beamer, the section beam is supported and driven by an electric motor. The
electric motor may be of either DC motor or AC inverter type drives spindles spindles which
support the section beams. The section beam wind the yarn sheet onto it. Generally, the
operator run the machines by depressing a Foot Pedal. As long as the Foot Pedal is depressed,
the machines continues to run and whenever the Foot Pedal is released, the machines stops.
In most of the LCB machines not incorporated with any automatic stop machines. The eyes of
the operator work to detect the end breakages. However it depends on the skills of the
This manual system of detection of end breakages is not a reliable system of detection of end
breakages in any Beaming operations. Some machinery manufacturer incorporated various stop
motions in re-beaming process in order to detect the end breakages in LCB. Few systems
normally available in the market is described below:
Drop Wire Stop Motions:
This type of stop motion system includes hanging of drop wires on each end of the dyed rope
yarns. This system is mounted just behind the comb where the yarn sheet is fully opened. An
electric contact bar is fitted underneath the drop wires. As soon as there is any end breakage,
the drop wires falls onto the bar which gives a stop signals. The advantage of this system is that
it is inexpensive. However, there is a drawback of fluff accumulations in the drop wires which
may create any malfunctioning of the system. The system is fitted near to the section beam. The
response and reaction time may be insufficient to prevent any missing end in the beam.
However this system not fully successful in detecting the broken ends.
Electronic End Break Detector
This system uses a photocell to generate a light beam which scans directly above and across
the full width of the yarn sheet. The system is mounted at the comb and delivery roll of the
beamer. Air is supplied from beneath the sheet of the yarn through a blower. At the time of an
end breakage, the air lifts the broken end up through the light beam and stops the machines.
There is also a drawback of lint and fluff generations which can false stop as the lint can dirt
through the light beam. The light beam intensity can be diffused which can also create
problems. However the system is mounted at close proximity to the section beam. Hence there
may be chances of missing end in the section beam even though the broken end detected by
Camera Scan System
In this system there is a specialized camera is fitted above and over the yarn sheet. The
camera is fitted at the point where the yarn sheet just opened. The camera “memorizes” a still
frame of the yarn sheet in the normal working condition of the machine and constantly
compares the ongoing frame with the memorized frame. Whenever there is any end breakages,
it initiate the machine to stop.
As the system is mounted further away from the beamer than other system, there is sufficient
time to stop the machine at the time of any end breaks and it may be possible to detect all the
broken end before being pass into the section beam. Hence there is little usage of Accumulator,
which also saves time and ultimately increases the productivity.
However the system having problem, as the system is sensitive to room temperature. Fluff
accumulation on the camera also cause malfunction of the system. If the tension in the yarn
sheet changed due to increase in brake pressure in the Tension stand, the opening rope
changes shape slightly and the system creates “false stop”.
Fig. 5: Typical camera based stop motion , WARPSCANNER
Typical camera based stop motion device, WARPSCANNER is shown in Fig. 5 . Generally the
WARPSCANNER is mounted above the yarn sheet. A reed / comb is required for perfect yarn
spacing. The cameras are focused on the yarn sheet at this point. Halogen lamps is fitted over
the yarn sheet at this point. The yarn sheet reflects lights back and the resultant image is
focused onto a linear CCD array in the camera.
The operator inputs the number of ends into the control. The processor scans the total number
of ends several times per second. If the count agree with the pre-set total number of ends, the
scan continues. If the count disagrees the warper receives stop signals and the end breaks is
identified on the LCD display.
In Long Chain Beamer, the WARPSCANNER is mounted at the beamer (Fig. 6). Fluorescent
backlighting is applied.
Fig. 6: Typical WARPSCANNER positioned in a Long Chain Beamer
When the diameter of section beam is increased, it is possible to develop “peak and valleys”
across the face of the section beam due to gaps between each yarn end. This problem can be
eliminated by using a press roll as used in a conventional warper. However it can also be
removed by using a traversing comb to overlap the lay of the yarn. This prevent the peak and
valley condition to occur.
All the Long Chain Beamer is equipped with automatic doffing and loading system. When the
section beam is full, the ends are gathered and cut away. It is then tucked onto the surface of
the section beam which is then doffed from the machine and an empty beam is loaded for
winding of a new rope.
Morrison MDS-RB 550 Long Chain Beamer
Morrison MDS-RB 550 Long Chain Beamer ( Fig. 7 &8)provides superior rope yarn opening with
Fig. 7: Morrison MDS-RB 550 Long Chain Beamer
The essential features are:
Flange diameter of 1 meter at the highest speeds can be achieved. Head is equipped with either
beams with journals or gear type heads.
The machines are equipped with Semi Automatic Beam Doffing system which facilitates for easy
removal of LCB beams.
Various functions like stop / jog / run, beam doffing, accumulator device, tension control system
The machine is equipped with pneumatic / hydraulic double end Disc Brakes for immediate stops
to minimize any missing ends in the beam.
The Sheet strummer at comb helps in the web opening with variable speed AC motor. This also
automatically lifts and lowers during machine stop / start.
Optional features are Press Roll with kick back to prevent scuffing of yarn and Elevated Back Up
Fig. 8: Passage of Rope in Morrison MDS-RB 550 Long Chain Beamer
KARL MAYER’s Long Chain Beamer, LCB Titan 1000
Karl Mayer offers the LCB Titan 1000 equipped with unique features ensuring superior yarn
opening and optimum beam quality. The essential features are:
Measuring device: The rope measurement is carried out on the overrun roll by means of
revolution count which ensures automatic stopping of the machine at the lease portion. This
minimize the manual mistake of stopping the machine at the leas length and reduce end
DNC control KAMCOS: The machine is equipped with Operator Interface IPC / Touch screen,
Ethernet interface, connection for the necessary data acquisition and Tele-service. The machine
is also incorporated with hardware and software package for easy link between machine and
Fig. 9: Reversing Drive Accumulator
Reversing Drive Accumulator ( Fig. 9): In this system the tension stand motor simply reverses
and with the help of a separate stand-by feed roller dumps, the accumulated rope back into the
coiler tub. This ensures fast accumulation / de-accumulation time. This also removes unneeded
rolls which can cause twist in the rope. This system requires less floor space and requires less
Single-end winder: The machine is fitted with a single end winder device to wind a single end
package from one end in the rope. At the time of any missing end in the rope, this end can be
Knot sensor: The machine is equipped with a knot sensor, mounted just above the diversion roll
of the accumulator. This sensor detects any knots or entanglement in the rope and stops the
machine instantly at the time of any entanglement. This prevents unwanted rope damage.
Fig. 10: Tension control dancer
Tension control dancer: During re-beaming, the tension in the rope is maintained by means of
Tension Control Dancer ( Fig. 10) which is equipped with a pressurized dancer and a feedback
loop. This sends a reference signals to the tension stand AC motor continuously and ensures a
consistent beam tension.
Braking device: The machine is equipped with Hydro-pneumatically controlled disc brakes fitted
on both sides of the beam axle, ensures rapid and synchronized stopping of the machine.
Drive for Rope Can: The machine is equipped with a rope can drive system through which the
rope Can may be rotated tub in any directions to reduce or eliminate twist in the rope.
Yarn Strummer: This feature ensures easy opening of the rope just before the warper head. The
automatic raising and lowering of the unit avoids yarn entanglement.
Fig. 11: Tension stand
Tension stand: The Tension Stand motor is operated in a regeneration mode which provides
power that is consumed by the beamer head ( Fig. 11).
Blowing device: In order to clean the reed, the machine is equipped with a blowing device which
clean the reed with compressed air.
The purpose of sizing is to increase the strength of yarn through chemically binding the fibers
with each other. The main object of sizing warp yarns is also to encapsulate the yarn with a
protective coating which reduces yarn abrasion that takes place during the weaving operation
and reduces yarn hairiness preventing adjacent yarns from entangling with one another at the
weaving machine. Also, this size protective coating also prevents the indigo dye from rubbing off
during the weaving. Sizing operations also involves multiplication of warp sheet from long chain
beamer sheets by collecting the yarns together and making one weaver’s beam. Normally, 8-12
% size is applied in sizing.
The performance of weaving largely depends upon the quality of the sized beam. In order to
achieve good performance in weaving, the sized warp beams should have certain
characteristics, such as:
The sized beam should have minimum number of yarn breakages, no crossed yarns,
low hairiness with no clinging.
The size add-on should be uniform through the length of yarn sheet,
Equal residual yarn moisture content,
No over-dried yarn.
No stickiness in the yarn
Equal yarn tension/elongation
high residual elongation in the yarn,
perfectly wound edges
For a long time, sizing of denim yarn normally carried out with starches or slightly modified
starches and binders. However, with the advent of different garment washed techniques and the
softness of the fabric required by the customer has led to new sizing recipes.
The components of a sizing machine are:
• Size Box,
• Drying Section, and
At the back end of a sizing machine, the section beams from the Long Chain Beaming process
are creeled. The yarn sheet from each section beam is pulled over and combined with the yarns
from the other beams.
There are various types of creels available today for denim sizing; each has its own advantages
and disadvantages. The common design of creels is as below:
Fig. 12: Typical Sizing Machine
In the cluster creel arrangement of a sizing range, the crosswalks are placed between each
cluster of 4 beams (Fig. 13). It allows passage for easy supervision and access to the operator.
In the long chain beamer beam, there is more chances of broken ends and lappers. Hence it is
more important to access the sizing back beam.
Fig. 13: Cluster Creel
In the magazine creel, there are two creel sections; one creel in the storage position can be
used for loading of re-beamer beam, while the other creel is in running condition. The
advantages of the creeling are higher productivity due to saving time in the set change. There
are different types of magazine creel available. The most common types are the side-to-side
and front-to-back/side-to-side. However magazine creel takes more space.
Another creel design is the rotating or carousel creel. In this creel design, two creel sections are
tied together and turn on a central pivot point. Rubber wheels ate fitted at the four corners of the
creel which allow the creel to turn. The back of the creel becomes the front of the creel in the
In the carousel creel design, the creel is rise up on a cushion of air and is motorized to rotate.
The creel can be loaded in remote locations, may be near long chain beaming and then pulled
on a cushion of air into the position behind the back of a sizing machine.
Fig. 14: Beam creel with tension controller
Creel braking is very important in denim sizing. The main object of brakes in a creel is to impart
a constant unwinding tension. The tension should be remain same from full to empty of the back
beam as well as during acceleration and deceleration. The primary guide roll going into the size
box is fitted on load cells. The tension of a single sheet or a number of sheet is measured by
means of a load cell. The tension controllers then control the tension by sending pneumatic
signals to each brake, if there is any difference between the actual tension and the desired
Karl Mayer tension controller beam creel (Fig. 14)
The features are
• Shaft less beam mounting with ball-bearing guide rollers. It is useful for beams having a
diameter of up to 1,400 mm
• Pneumatically operated band brake for beam braking
• Controlled braking pressure for keeping the yarn tension constant.
Size box is one of the most critical component of a denim sizing machine. The application of
size on the yarn should be uniform to provide necessary protection during subsequent process,
i.e. in weaving. The number of size boxes is also an important criteria of efficient sizing. The
number of size box depends on the space occupied by the yarn in a given sheet width.
The number of size boxes is also depends on the type of weaving machines used in the plant. If
the sized yarn is woven on a high speed air jet loom, then the uniformity and the quality
requirement of the sized beam is higher than on a projectile looms. Hence for air jet looms, two
size boxes is recommended.
When the yarn sheet enters the size box, the yarns are guided downward and passed through
the size paste in the size box. Then the yarn sheet passed through a set of squeeze rolls. The
squeeze rolls control the wet pick-up, and influences the size add-on onto the yarn.
After the size boxes the yarn sheets are dried by passing over steam- heated, Teflon coated
cylinders. Different capacity of cylinder in sizing is shown in Fig. 15.
After the drying zone, the yarns pass through a set of stainless steel split rods. The function of
the split rods is to separate the yarns into individual sheets, equivalent to the number of section
beams in the creel. The yarn sheets then collected into one single sheet and passed through a
expansion comb, which separates individual yarns. The yarn sheet then wound onto the loom
Fig. 15: Typical Sizing design and Passage of yarn
KARL MAYER offers sizing machine for denim which meet all the requirement of sizing in order
to achieve high productivity in weaving.
KARL MAYER ‘SMR’ sizing technology for the DENIM sector
SMR sizing machine (Fig.16 ) with KARL MAYER’s KAMCOS® control technology offers user-friendly
operation and produce high quality, uniform, reproducible sized beams, which are needed in modern
high-speed air-jet, rapier and shuttle looms.
The machine is equipped with CSB universal size application system which ensures compact yarn feed
and short yarn paths. Cylinder driers available as “full warp” or “sectional warp” versions which ensures
fast drying. The Tension-controlled roller compensators ensures constant production speeds with a
weaving beam changing times of < 3.5 minutes,
Fig. 16: Graphic und Layout of SMR sizing machine
‘BC-A’ beam creel and ‘ABR’ controller
The KAMCOS® system, the associated data collecting system and an efficient braking system keep the
yarn tension constant through out the warper beams. The KAMCOS® system continuously send the
values of required pneumatic braking and stopping pressure for the current diameter of the beam. Then
the yarn tension measuring rollers (load cells) in the ABR control system operated. Flexible band brakes,
which are controlled by low-friction roll diaphragm cylinders, equalize any fluctuations between the actual
and target values.
CSB-Compact Size Box
The CSB-Compact Size Box ( Fig. 17) is operates with Double dip, double nip sizing technology, which
requires minimal number of rollers due to tangential squeezing. It offers an integrated application system
for the DENIM sector. Normally, two sizing machines are used when the yarn loading density was higher
than about 70/80%. Whereas in CSB system can be used up to 110% yarn loading volumes. The
Compact Size Box with a low liquor volume and constant-pressure rollers can be operates at up to 40
Fig. 17: Compact-Size-Box (CSB)
The essential features are:
The size box is easy to access, maintenance and cleaning
The size box having a low liquor volume which is up to 60 % lower than in conventional size
The coordinated rubber-coated rollers avoids differences in circumferential speed,
The optimum squeezing and wetting technology ensures higher yarn loading volumes (of up to
110 %) in the single-bath process
CSB-PW - Compact Size Box with pre-wetting
The Compact-Size-Box with pre-wet (CSB-PW) consist of Double dip and double nip in both the sizing
and the pre-wet section. With the ‘wet-on-wet’ size box (Fig.18 ) the additive can be applied onto the yarn
which is pre-wetted with water.
The warp yarns passed through a separate pre-wetting section in which the yarn sheet absorb up to 40 %
warm or hot water. The pre-wetting section consist of high pressure squeezing arrangement. The
absorbed water, mainly bound by capillary action, prevents the size paste from penetrating inside the
yarn. The advantage of the pre- wetting system is that the sizing agents and dyes can be subsequently
washed out more easily, and saves up to 20 % of the size.
Fig. 18: Compact-Size-Box pre wet (CSB-PW)
Size application regulation
The wet-on-wet sizing technology equipped with automatically control and regulate the size pick-up
system. This system can also be equipped with a microwave measuring instrument and a squeezing
pressure regulation system at the size box. (Fig. 19 & 20 ). The moisture of the warp is measured and, if
any deviation found from the nominal value, the squeezing pressure is automatically re-adjusted .
Fig. 19: Diagram of a CSB box with integrated Pleva measuring technology
Fig. 20: System automation, 1 Microwave for yarn humidity measuring, 2 Refractometer, 3 Flowmeter
Size liquor concentration control
The size liquor concentration in the size box can be automatically determined of via on-line refractometer
Including % display via computer ( Fig. 21).
Fig. 21:On-line refractometer
The dryers having an important role in efficient sizing and to avoid yarn abrasion and fibre and yarn
hairiness which occur as the warp yarns rub against each other and during opening of the warp yarns that
are clinging together. The Teflon-coated cylinders reduce yarn hairiness and clinging. The Karl Mayer
sizing machine dryer may be of multiple configurations, Teflon coated and equipped with temperature
control devices. The automatic moisture control configured either as a floor layout or overhead version of
Above the drying cylinders there is a suction hood made of stainless steel with extraction fans,
Cylinder drier floor version
Cylinder drier overhead version
Cylinder drier overhead version
Fig. 22: Cylinder Driers
Warp yarn storage device and beam production
Warp yarn storage compensators device stored the warp lengths of up to 144 m and enabled the sizing
machine to continue running even at the time of beam changing. This avoids over drying the sized yarn at
the time of beam changing and hence ensures better and constant sizing values.
The beaming machine is equipped with an expansion comb and taping device, pneumatically controlled
press roller unit, hydraulic beam loading and doffing system, beam chuck in motor-driven movable
supports. The automatic measurement of the beam diameter through ultrasound sensors, steady and
even winding tension during the whole process makes it extremely user friendly. Working widths up to
5400mm and flanges diameters up to 1600mm can be achieved in this sizing machine.
Delivery roller set and main reed
Hydraulic beam loading and
1600mm flange capability
KAMCOS® drive and control technology
The low yarn elongation loss in sizing is a major requirement in sizing in order to achieve optimum
efficiency in weaving. The yarn distortion must be monitored and controlled precisely when the yarn sheet
passes through the sizing machine. The frequency controlled multi-motor or individual motor drive
technology equipped in modern sizing machines can set the yarn elongation accurately zone by zone.
By using this yarn distortion control system, the yarn distortion forces can be monitored and kept
constant. With the KAMCOS®s zone elongation control system, the variations in sizing, can be equalised
The yarn tension measuring rollers supplied information to KAMCOS® system accurately. It has been
possible to reduce the overall yarn distortion by as much as 0.6 % using the KAMCOS® control
Toyota Spun Sizer, Pre-Wet Sizing System
Toyota offers Pre-wet sizing system in which the yarn passes through hot water and squeezing
out excess moisture before applying size (Fig. 23). The Pre-wet sizing system removes cotton
wax and foreign matter and ensures a thinner, more uniform size application. This also reduce
the size consumption. The reduce in size also cut the desizing cost in subsequent process.
Fig. 23: Toyota Spun Sizer, Pre-Wet Sizing System
7) www.toyota-industries.com › Business Overview
8) Papers on National Seminar on Denim, 30th & 31th August 1996, The Textile Association (India),
Click here to read Part-II
The author is Manager (TQM) at Shri Lakshmi Cotsyn Limited, UPSIDC Industrial Area, Malwan, Dist.