Weaving & Weaving Preparation At ITMA 2007
New developments in weaving and weaving preparation equipment provide a range of opportunities for woven fabric manufacturers.
By Abdel-Fattah M. Seyam, Technical Editor
Italy-based Savio Macchine Tessili S.p.A. showed its Polar automatic winders. The Polar winders are available with different variations designed to meet customers’ needs in different countries. For example, the Polar I is designed for use in countries with high labor wages.
The company has developed several new elements for the Polar automatic winders including Computer Aided Density, Computer Aided Metering, a heat splicer, and a doffing concept that doffs in 13.5 seconds. The package density is controlled by yarn tension and the contact pressure between package and drum. The density system is designed to control the contact pressure using an electronically controlled pneumatic system that adjusts the pressure of a counterweight piston to a predetermined value suitable for the required package density. Today’s winders are equipped with metering systems to get equal yarn length on each package — a must to avoid waste in downstream processes such as warping. The metering system developed for the Polar winders meters the packages using a combination of a laser detector for the package and speed sensor for the drum. According to Savio, air splicing combined with heat give an excellent appearance and good strength of the joined yarn. The main applications of air/heat splicing are high twist, mule spun, wool and wool blend yarns.
At ITMA, Oerlikon Schlafhorst, Germany, showed its new fifth-generation Autoconer 5 automatic winder, which was introduced in 2006 and has been sold to Egyptian and Indian textile companies so far. The new features of the machine include wax disc consumption monitoring, separate drives and a package metering system called Ecopack FX.
Wax consumption is monitored by a sensor, and the system signals the operator when it’s time to load a new disc. The disc is mounted 90 degrees to the traditional direction and the traverse motion of yarn allows it to rub against the wax disc. The amount of wax required on the yarn can be controlled by the disc’s rotational speed, direction of rotation and angle of contact. The sensor is a magnet that detects the movement of a spring-loaded element named the wax adopter. As the wax is consumed, the adopter, which is pressing on the wax disc, moves backwards when the thickness of the wax disc reaches a small, critical thickness and a signal is shown to the operator to replace the wax disc. The winder is equipped with several motors to independently drive the package, wax disc, upper splicer arm and lower splicer arm.
Ecopack FX is a system for measuring yarn length to produce packages of equal length within 1-percent deviation. In this system, the yarn length is optically measured.
The Autoconer 5 is currently offered with a grooved drum. The Autoconer 5 on display at ITMA had several spindles with grooved drums and some spindles with a smooth drum. The company is still developing machines with a smooth drum to be marketed in 2008. The yarn traverse is achieved by a reciprocating element with a U-shaped right short leg. It is termed “wiper” since its motion is similar in nature to wiper motion. The wiper is driven independently by a separate drive so its motion can be changed. This enables control of the traverse speed, traverse stroke and winding angle; and precision winding or random winding. The wiper motion can be controlled to work as an anti-ribboning mechanism by changing traverse speed at critical package diameters.
Germany-based Karl Mayer Textilmaschinenfabrik GmbH introduced its newly developed Smart Beam at ITMA. The warp beam data — including style number, order number, number of warp ends, number of beam rotations during the warping process to form the entire warp, warp length, number of beams in the size set, beam number, yarn thickness and count, number of yarn plies, material, warp density and a list of missed yarns — is transferred wirelessly using radio frequency technology from the warper computer to a chip attached to the warp beam. When the smart beam is loaded to the sizing machine, data are wirelessly transferred from the beam chip to the sizing machine’s computer. Based on the information transferred to the computer, the size recipe is determined using data in the existing database. Size recipes for a new style are proposed by the system.
Warping machine manufacturers responded to the need for companies to transform from mass production of a few styles to much shorter order lengths of numerous styles. The only sample warper that was shown at ITMA 2007 was Karl Mayer’s GOM 24 Gir-O-Matic sample warper, which is an upgrade of the company’s GOM series in terms of creel capacity. The number following “GOM” indicates creel capacity. Features of the GOM 24 sample warper include: automated processing with minimal operator intervention; automatic leasing for drawing-in and size rod separation; programmable leasing pattern; programmable color selection; minimal waste; sample and small-order production possibility; 24-packages-capacity rotating creel; creel equipped with feeders to handle high beaming speed; magazine creeling for high efficiency; computerized color selection for intricate patterning; and warp length capability of up to 1,000 meters.
Switzerland-based Benninger AG showcased its new Versomat sectional automatic warper, designed to form extremely narrow warp bands with few wound packages. It can handle a broad range of yarn counts as well as yarn types, and can be used for extremely short or long production runs. Warp-band formation is continuous without cutting after the completion of each band. The cutting is done after all bands are warped. This system obviously can compete with sample warpers. In sample warping, as little as one package can be used to form the entire warp. Additionally, the color order is totally flexible in sample warping, a feature not possible in the case of other sectional warpers.
Ira L. Griffin Sons Inc., Charlotte, showed its newly developed ball warper and long chain beamer for sectional beams for denim fabric production. Ball warper features include stops at the center to avoid slough-off, an anti-patterning mechanism, and electronic tension control. Long-chain warper features include an AC motor to control the warp-band tension level, and an endless accumulator to put the warp back in the tub in case the beamer motion is reversed to find and repair broken ends.
Karl Mayer Rotal S.r.l., Italy, showed an ergonomically designed beamer for sized warp beams. The comb can be moved forward toward the operator to thread the ends so the operator does not have to extend his or her arms and bend his or her back to reach to the comber. After threading, the comber is moved backward to its running position. The easy beamer also is equipped with a movable operator panel that can be moved to any position across the front of the machine.
Germany-based Sucker Textilmaschinen GmbH highlighted a new size box for its Sucker Comsize II sizing machine. The warp sheet passes under a tension-measuring roll connected to a control system for constant warp sheet tension. The size box is equipped with three rollers with two squeezing nips. The size solution is applied on the warp sheet by a spraying system to provide enough time for solution application; then the size is squeezed by the first nip, and the warp sheet is immersed in the solution and squeezed again by the second nip prior to exiting the size box to enter the drying zone. The size box is smaller than traditional boxes, and the amount of size solution in the box is small. A short pass of the warp sheet provides improved guidance, reduced waste, improved control of size solution temperature and reduced heating energy. The size feed inlet provides flow of the solution in one direction to continuously bring fresh material to the size box. The excess solution overflows into a container connected to the size box and the size solution storage tank for recycling after filtration. The temperature of the solution is controlled by two systems. When the temperature has reached the required level, one heating system may turn off while the other keeps heating the solution to allow less fluctuation of the desired temperature.
Drawing-In And Tying-In
Knotex Maschinenbau GmbH, Germany, showed its new double end detector for warps without lease. The double end is detected by a pressure sensor that measures yarn tension during tying up to 10 times per second. For double end, the detected tension will be much higher compared to single end. Knotex also has developed a system to detect whether the warp is leased. The machine then adjusts itself and prepares for detecting double ends if there is no lease — otherwise, the double-end detector is not activated.
Another innovation introduced by Knotex is the Autoframe® fully automatic tying-in system. The operator enters the warp and material, then the system automatically adjusts the required pretension using servo motors. This concept enables the operator to spend only a short time setting the machine.
The new Basic S tying machine — S for speed — is designed for tying solid-color warps of cotton, wool linen, or their blends. The machine is preset for such warps, and is ready to tie up to 600 knots per minute.
The company also showed the new RS 1HPlus reeding machine. The reeding is conducted using compressed air, and the machine is equipped with a yarn break detector.
Stäubli International AG, Switzerland, introduced Magma, a new tying-in machine to complement the Topmatic tying-in machines. The Magma handles coarse yarns that could not be handled by the Topmatic. The machine is equipped with a new, patented system for separating yarns from the lease. It can tie spun, multifilament, monofilament and polypropylene ribbon yarns in a count range from 0.3 to 50 Ne. The machine detects double ends using an optical sensor. It may perform single or double knots by a push of a button. The knot end’s length is adjustable and can be set as low as 5 millimeters (mm). The machine is designed to have minimal mechanical parts and requires minimal maintenance.
Stäubli also exhibited a new automatic drawing-in machine, the Safir, which builds on the proven Delta drawing-in technology. Safir draws in warp yarns directly from the warp beam. Yarn separation is achieved using a vacuum gripper, the same one that is used in the Opal leasing machine. A double yarn detection system is incorporated into Safir. It is also equipped with color recognition for each thread at the separation stage. Safir can draw in warp yarns from two warp beams, and each beam may contain up to eight layers without the need for lease. Thus, the leasing step is not required. The Safir combines the Delta and Opal technologies into one machine, which increases the efficiency of the preparation processes. With the Safir, striped patterns in the warp direction can be produced easily. Stäubli will offer the Safir commercially in 2008.
Weaving: Shedding Systems
Stäubli commercialized the Unival 100, designed for jacquard shedding, in 2003. The Unival 100 controls each harness cord using an actuator. In 2007, Stäubli expanded the Unival range, adding the Unival 200 and 500 shedding systems for narrow jacquard and dobby weaving, respectively.
The Unival 200 jacquard system for narrow fabrics was shown at ITMA weaving labels. It features the same actuator as the Unival 100, but with different power and size. The actuation is not limited to controlling the shedding motion, but also controls the main motions of the machine including: weft tension with individual control for each weft yarn, which can be preprogrammed digitally; weft feed rate; warp tension; cloth take-up rate; latch needle for securing the filling yarn; and filling selection — up to eight colors — selected filling introduced to open hook rapier for insertion.
The principle of shed formation in Unival 200 is shown in Figure 1. Each warp yarn is controlled by an actuator and toothed rack whereby the yarn is threaded through an eye at the top end of the toothed rack. The selection of warp yarns to be raised or lowered depends on the rotational direction of the actuator control gear. The gear is turned to a certain angle in a counterclockwise direction to raise its associated warp end, or is turned in a clockwise direction to lower the warp end. This is a positive shedding system, as the lower and upper sheds are controlled with the actuation and no returning springs are used. The Unival 200 system can be extended to weave wide jacquard fabric using any insertion system. Obviously, such a system eliminates the gantry, comber board, pulleys, magnets, springs and harness cords.
Staübli’s Unival 500 uses more powerful actuators to control harness movement in a dobby shedding system. Each harness is controlled by an actuator that controls links connected to the harness. Again, clockwise and counterclockwise rotation of the actuators determines which harnesses will be raised or lowered to form the shed according to the weave design.
At ITMA 2007, Italy-based Smit S.p.A. showed the Twin Direct Drive independently driven dobby shedding system on its new GS920 – S 200 N 8 SP rapier weaving machine. The Twin Direct Drive system uses two motors. There are a main drive and a dobby shedding motion drive, which are synchronized wirelessly for proper timing of shedding motion, filling insertion and beat-up motions. The use of two drives provides independence of shed timing from other events on the weaving machine. It is possible to have different shed timing for each pick in the repeat of the weave design. For example, if the construction requires filling yarns containing spandex and standard yarns, the spandex yarns can be inserted with early shed and the standard yarn can be inserted on normal timing. Another advantage of the system is noise reduction because there are no parts connecting the main motor to the dobby motion.
At ITMA ’99, Germany-based Grosse Jac Webereimaschinen GmbH introduced the first UniShed prototype — now known as UniShed 1 — and showed it again at ITMA 2003 with some improvement. At ITMA 2007, an improved version of the machine was introduced with the name UniShed 2, which is still in the prototype stage and is expected to be commercialized within a year. The UniShed shed formation is achieved using buckling leaf springs. A set of leaf springs is connected to a heddle wire that controls one warp end. The leaf springs, which are controlled by actuators, control the bottom shed by buckling downward and the top shed by buckling upward, according to the open-shed principle. The difference between UniShed 1 and UniShed 2 is in the way the spring leaf set is deformed. UniShed 1 uses the Euler 2 mode of deformation in which the leaf spring is hinged from both sides, while UniShed 2 employs the Euler 4 mode of deformation in which the leaf spring is clamped from both sides. The deformation of the leaf springs in the Euler 2 mode creates a half-sine wave, which causes the ends of the leaf springs to slide past each other in a manner that causes instability between the heddle wire and the leaf springs. Euler 4 creates a complete sine wave, which eliminates the instability.
The configuration of the jacquard head and the individual control of each heddle wire allows the heddles to be set vertically. These settings permit the elimination of harness cords, magnets, hooks, pulleys, springs and the gantry, resulting in reduced building and air conditioning costs. The jacquard head can be mounted directly on the side frames of the weaving machine, thus making quick style change possible in jacquard weaving because it is easy to exchange the entire jacquard head including the heddles. The preparation of the new style can be done in the drawing-in room with the desired number of warp yarns and warp density.
Switzerland-based Jakob Müller AG Frick’s Digital Direct MDLA label-weaving air-jet machine equipped with the new jacquard concept — shown for the first time at ITMA 2003 — was one of the main attractions at ITMA 2007. The patented shedding system allows the elimination of gantry, pulleys, harness cords and comber board. In this system, each warp yarn is individually controlled by a special heddle and retaining hook. The heddle element is a hollow structure that accommodates the hook element inside. Shed formation is achieved using a roller that moves down and up in every weaving cycle. The initial warp sheet position is in the upper shed, and the bottom shed is formed when the roller pushes the warp sheet down and the selection is made for warp yarns for the lower shed. The selected warp yarns are retained at the lower shed by the hook elements. The heddle element is kept in its upper position using an activated magnet, and, as a result, the hook does not obstruct the warp end that moves up with the roller. If the magnet is not activated, the heddle is kept down by a spring, and thus, the hook retains the corresponding warp at the bottom shed.
While the MDLA machine was shown weaving labels, the concept can be extended to weave any type of fabric using any type of filling insertion system.
And Range Of Fabric Types
Weaving machine manufacturers exhibited a range of machines capable of weaving a broad range of fabrics at high speeds. Switzerland-based Sultex Ltd. did not show its multiphase weaving machine M8300, which had been shown at every ITMA since 1995. This may be because of low demand as a result of the machine’s limited weave structures and warp and pick densities. Water-jet machines also were absent at ITMA 2007.
Air-Jet Weaving Machines
Air-jet weaving’s ability to adapt to new markets continued to be demonstrated at ITMA 2007. This is related in part to further improvement of adaptive control systems that control the air speed, and the rate of filling yarn insertion through the shed. Companies with air-jet weaving machines on display at ITMA included Japan-based Toyota Industries Corp., Japan-based Tsudakoma Corp., Smit, Sultex, Germany-based Lindauer Dornier GmbH, the Italy-based Itema Group with its Somet and Vamatex brands, and Belgium-based Picanol NV.
Toyota’s JA2S-340TP-ET-T170 air-jet machine was demonstrated weaving 3.11-meter-wide bed sheeting at a rate of 750 picks per minute (ppm) with four insertions. The four yarns were fed from four weft packages to one filling feeder. While this is a much simpler way of handling the filling yarn compared to using four feeders, the fabric hand may be affected due to twisting of the four weft yarns while being unwound from the feeder during insertion — every coil on the feeder causes one turn in the weft yarns. Additional turns may be added during transport of the weft yarns through the profiled reed. Analysis is required to check whether this setting may produce thicker, rougher fabric compared to other multi-weft insertion techniques.
At this ITMA, Picanol’s OMNIplus 800 4-P 190 air-jet machine ran at the highest speed — 2,007 ppm — a record for single-phase weaving. The record of 3,222 meters per minute rate of filling insertion (RFI) of Tsudakoma’s ZAX-190-2C machine shown at ITMA ‘99 was not broken. This is obviously due to the difference in the warp width in the reed.
Dornier’s new CLS air-jet machine with Stäubli dobby is equipped with a new drive termed SyncroDrive, designed for a machine equipped with dobby shedding motion. The drive focuses on the stability of rotational speed. The SyncroDrive system concept separates the large dobby mass from the drive at the starting moment. This permits a high-speed start and elimination of start marks. The CLS machine was shown weaving fine worsted menswear at speed and filling insertion rates never before reached for such a fabric.
Rapier Weaving Machines
There were more rapier weaving machines on display at ITMA than any other type of weaving machine — thanks to the versatility of this technology in handling filling yarns. This technology can handle any type of filling yarn and can switch from very thin yarn to heavy yarn, slub yarn, fancy yarn, or multiple insertions in the same fabric without the need for a complex control system. Companies exhibiting rapier machines included Smit, Sultex, Dornier, Itema, Picanol and Italy-based Panter S.r.l.
Machines, Selvage Technology
Projectile weaving continues to be dominated by Sultex. Only one machine — model P7300HP V8 B 390 N 2 EP weaving heavy denim at 400 ppm and an RFI of 1,497 m/min — was exhibited. The declining number of projectile machines is an indication of the growing popularity and demand for air-jet and rapier machines because of their versatility and speed.
Smit showed a new tuck-in selvage-forming system for centers and edges. The system is developed for terry fabrics and was shown with Smit’s new GS920 – B 260 F 8 J rapier machine, equipped with drop back reed. The tuck in works when the reed moves forward to beat up and develop the loop. It can be adjusted to tuck-in for different terry designs — three-pick and five-pick, for example. The company also showed a tension-control mechanism designed for terry fabrics that uses a three-roller system — including the back rest — to monitor and control pile warp tension. The mechanism guarantees loop height consistency by monitoring and maintaining constant tension.
Looking at the weaving speed and RFI at this and previous shows, it can be said changes are not a significant indication of reaching the limit for single-phase weaving. One way to exceed these limits is to develop multiphase weaving machines that can be equipped with dobby and jacquard shedding systems.
Reduction In Energy Consumption
Energy costs are dramatically increasing. At ITMA 2007, several developments for saving energy in air-jet weaving were exhibited — energy consumption is known to be high in air jet. It is well-documented that filling yarn arrival times get shorter and shorter as the filling yarn package gets smaller because of yarn structure changes from the outside to the inside of the package. Variation of yarn surface structure from pick to pick also is possible. Adaptive control systems have been developed to address this issue. More developments in these systems have been reported by several machine manufacturers.
Adaptive relay valve drive (ARVD) is an automatic system from Picanol that controls the closing time of the relay nozzles on a pick-by-pick basis because these nozzles consume 75 percent of the air used during weaving. The system monitors the winding information of the filling feeder and decides the closing time of each relay nozzle for each pick accordingly. The relay nozzle valves close early with package size reduction. Consequently, compressed air consumption is reduced. Picanol reported the system works well with a broad range of spun and filament yarns.
Another development by Picanol is the Autospeed system, which automatically increases weaving speed to keep the arrival moment fixed, thus reducing energy consumption per fabric unit produced. The pneumatic catching device (PCD) is a new system that mechanically arrests the filling yarn at the arrival end. The device is operated by two air-controlled plungers. The first plunger is for clamping, and the second is for stretching the filling yarn and keeping it under constant tension. The device is located on the reed next to the filling sensor. The devices replace the relay nozzles for holding and stretching the filling yarn and also reduce air consumption by up to 30 percent, according to Picanol.
Active Weft Control (AWC) is a new system from Sultex that optimizes air consumption by placing the relay nozzle valves close to the nozzles. The system was shown on air-jet machine L5500 at ITMA 2007. In traditional versions, four relay nozzles are controlled by one valve. Optionally, two nozzles are allocated to one valve. The main component of the system is the Real Time Controller (RTC), which monitors the yarn’s progress during insertion and controls the relay nozzles to optimize their blow time accordingly. Sultex claims the system may reduce air consumption by 10 to 40 percent depending on the yarn type and machine width.
Toyota introduced the Automatic Pick Controller on its JAT710 air-jet machines. The system automatically synchronizes air injection of the conical tandem main nozzle with the arrival of the filling yarn. It is claimed the system reduces air consumption by 20 percent.
Tsudakoma introduced the Twin Nozzle Valve designed with a secondary chamber. The system allows sharp air jetting for a quick response to speed. The company reports air consumption is reduced by 10 percent.
Dornier introduced new relay nozzles, special stretch nozzles, and TandemPlus main nozzles. According to the company, the new designs reduce air consumption by up to 28 percent.
Picanol and Dornier showed new mechanical clamps for air-jet weaving — both companies have applied for patents. Picanol’s clamp is a mechanical device operated by air. The system clamps the filling yarn when it is not being inserted. The recognized advantages of the system are: elimination of continuous or significantly reduced air flow; prevention of filling yarn damage resulting from air flow; reduced snarling of high twist yarns containing spandex, resulting in fewer defects and/or stops; and low twist and slub yarns processing without blowing the tip off at the start of insertion. Dornier’s mechatronic Positive Weft Clamp (PWC) eliminates the use of compressed air and clamps the filling thread until it is ready to be inserted into the shed.
Material Waste Reduction
Dornier showed its new DuoColor device for rapier weaving, which reduces filling waste by reducing the length of fringe. Depending on yarn type, selvage waste can be reduced by more than 50 percent. The DuoColor is limited to two types of yarns. It was shown on the PTS 2/S 20 rapier machine weaving ballistic fabric from aramid yarns to demonstrate waste savings for such expensive yarns.
Sultex also showed a filling-yarn waste-saving device on one of its new rapier machines, the G6500 W 190 F 4 SP, which was weaving protective aramid fabrics. The machine features a special filling brake system to reduce its speed and thus control filling length precisely, reducing waste.
Italy-based Bulgaro Officina Meccanica S.n.c. showed a weaving machine equipped with a fan reed that can be preprogrammed to provide design effects. The reed’s vertical movement varies the warp density from high to low along the design in the warp direction. The loom was also modified to produce pleated effects by reversing the fabric take-up and let-off to allow high beat-up force. The combined effect is a pleat that protrudes out of the fabric surface.
Germany-based Genkinger Hubtex GmbH showed its new material handling equipment for weaving and knitting with a range of applications — from transporting empty beams, full warp beams, sized beams and cloth rolls to drawing-in systems for warp beams, drop wires, harnesses and reeds. The battery-operated KEFU 30 transport system can quickly — at 8 to 11 kilometers per hour, depending on load — transport empty and full warp beams weighing up to 3,000 kilograms (kg) from one room to another. The servo steering of this system allows maneuvering in tight spaces, and the system can handle wide beams ranging from 700 to 1,300 mm in diameter.
Genkinger Hubtex’s EE-KHUR 25 system is ideal for transporting full beams made of sensitive yarns to the weaving room. The system supports the beam from the bearing ends without touching the warp yarns. The maximum load it can handle is 2,500 kg, and it is equipped with smooth lateral and extended movements for easy transfer of the beam from the system to the loom.
The EE-GYR 25 system, with a capacity of 2,500 kg, is designed to deliver warp beams to terry weaving machines that require two beams. The design of this truck is compact, with narrow transport width.
The demands on high-performance weaving are on the rise, and traditional heddle wires with sharp edges are harmful to high-performance fibers. There is a desperate need for heddles with rounded edges. Responding to this demand, Switzerland-based Grob Textil AG developed new heddles, termed TWINtec, for such brittle yarns. The heddles also are suitable for weaving tapes, keeping the ribbon orientation without twisting. The heddle eye is formed between two small, smooth rods that provide a low friction, round surface of contact.
Shuttle Weaving Is Back In Demand
Shuttle looms — last shown at ITMA ’79 — have been replaced by the advances offered by high-speed shuttleless weaving machines. Though declining, the number of shuttle looms operated in the world is still higher than the number of shuttleless weaving machines. The number of shuttle looms will continue to decline, but they will not disappear. Many specialty fabrics produced using shuttle looms cannot be produced by shuttleless weaving, including fire hoses, endless belts and artificial blood vessels. With the availability of parts from old looms waning, and the outdated technology found on shuttle looms, weavers are demanding that manufacturers produce new looms featuring today’s electronics and technology.
Germany-based Mageba Textilmaschinen GmbH & Co. OHG has responded to the demand with the development of the new SSL MT and SL series looms. At ITMA 2007, the company showed two shuttle looms producing tubular fabrics. The SL loom is designed for single narrow fabrics up to 80 mm in width, and is equipped with a 200-ppm-maximum-speed variable drive. The SSL MT 170 model is designed for multiple narrow fabrics up to 150 mm wide. Multiple shuttles — up to four for each fabric — are available to permit production of medical fabrics for implants such as bifurcated implants. The looms can be equipped with dobby or jacquard shedding systems to produce intricate fabrics for labels.
It is believed that more weaving machine manufacturers will follow suit and begin manufacturing wide shuttle machines for special needs.
The new developments in weaving and weaving preparation equipment provide a range of opportunities for woven fabric manufacturers. The growing use of electronic controls has led to a reduction in heavy mechanical parts and provides machines that can be maintained easily. Some manufacturers have responded to the need to reduce the environmental impact through reduction in energy consumption and raw material waste. Future ITMA shows are expected to reveal more advances in this direction because of the mounting pressure arising from energy and raw material cost increases. The continuous demand in developed nations for equipment to handle much smaller orders with minimal waste has been met by developing new sample and sectional warpers.