STÄUBLI`S ACTIVE WARP CONTROL SYSTEMS SUCCESS IN WEAVING

STÄUBLI`S ACTIVE WARP CONTROL SYSTEMS SUCCESS IN WEAVING Ozan Çöteli 1, Fritz Legler 2 1 Stäubli Sanayi Makine ve Aksesuarları Tic. Ltd. Şti. Istanbul / Turkey 2 Stäubli Sargans AG, Sargans, Switzerland O.Coteli@staubli.com Abstract Weaving preparation through active and automatic drawing-in of warp ends is a decisive stage prior to weaving is gaining importance for modern weaving mills to remain competitive and to provide quick response in a demanding market environment. Ever changing demands and short delivery times require flexibility in warp production and the ability to adapt to the buyers needs. The capacity and throughput times in weaving preparation need to be designed to fulfil the requirements of the weaving shed in order to avoid downtime. Modern solutions to optimize and rationalize the weaving preparation process are part of the presentation. In order to match the specific needs of the market a mill has to optimize weaving machines with the right shed forming technology. Adequate under-motions and frame drive systems are available to match high speed requirements of state-of-the-art weaving machines. Focus will be given to latest generations of shed forming systems which guarantee high speed and performance as well as high quality and production reliability. In summary, technical and industrial textiles are in demand a quick overview of Stäubli`s activities in this field with some examples of applications will be given in this paper. Key Words: Shedding, dobbies, cam motions, automatic warp drawing-in, weaving preparation, technical & industrial textiles 1. THE STÄUBLI GROUP Stäubli is a multinational industrial company that designs, manufactures, and markets products for the sectors textile machinery, industrial connectors, and robotics. In all these sectors, Stäubli delivers customers worldwide with high-grade solutions incorporating proven and advanced technologies. The textile machinery sector has more than 120 years of experience, producing systems for shed formation on weaving machines, weaving preparation systems and carpet weaving machines. The industrial connectors sector manufactures and markets a wide range of connecting elements for pneumatic and hydraulic assemblies, gases and liquids, and combinations of these in multi-coupling systems for specific applications. In the robotics sector, Stäubli produces high-precision high-speed industrial robots for demanding automation applications. The Stäubli Group is headquartered in Switzerland, where the original company was founded in 1892 on Lake Zurich. Today the Group operates 12 industrial sites and a network of 25 sales and after-sales units worldwide, including sales agents in over 50 countries. 406

2. EFFECTIVE CONTROL IN WARP PREPARATION The buyers market shapes the business environment today. Not only in international business but also at the national level buyers demand on-time delivery, top-quality fabrics, and very short delivery times. This has manifold consequences for textile and cloth manufacturers respectively weaving mills. Optimised manufacturing processes along with better product quality are necessary to succeed in this increasingly competitive market mills must weave cost-effectively and deliver on time. And of course all of this within the tight corset of economic feasibility. Companies must therefore analyse their processes and production steps to find opportunities for optimisation. Challenges in cloth manufacturing Quick turn-around of orders of more demanding fabric styles in different yarn combinations gain importance these days. Top of the line cloth manufacturers and weavers cope well with following challenges and requirements within the supply chain: Table 1. Challenges in cloth manufacturing Warp Preparation Weaving Operation Cloth buyers / market More styles to be prepared in less time Finer, more delicate yarns to be drawn Denser warps and/or more critical patterns to be prepared Non-availability of labor Shorter runs / warps (quick style changes) Shorter through-put times, higher efficiency requirements Better loom-state fabric quality Short delivery times Pressure on margins Short piece length Effective Warp Preparation from manual to automatic drawing-in It all starts with a good warp! The drawing-in department is the heart of the weaving mill. It not only determines the productivity of the mill, it influences other departments within the company. Looking at traditional manual drawing-in departments, it becomes more and more apparent that they have been reaching the limits of their capacity in recent years. Demands for reliable on-time delivery and flawless goods are constantly increasing. Decisive is whether the drawing-in room is able to supply to the weaving room the required number of completely drawn in warp beams (complete harnesses, reed). The increasing need for product changes requires more and more personnel in the manual drawing-in department. The trend towards high-quality fabrics and the use of increasingly finer yarns and denser fabric styles increases the number of ends to be drawn in. Furthermore, it is becoming more and more difficult to find suitable personnel, and willingness to work in this field is gradually disappearing. The effort required to organise the relatively large staff in the manual drawing-in room is considerable. Once the warp ends are drawn into the heald frames, healds and the reed at the various drawing-in stations, the drop wires must very often still be pinned on the weaving 407

machine. Here, organisational tasks above all, synchronisation are a challenge for the mill management and unfortunately often lead to lengthy idle times for the weaving machines. Particularly for modern, high-performance weaving machines, such idle time is very disadvantageous. Open drop wires (used with manual drawing in) lead to more weaving machine stops than closed drop wires do. Thus solutions are needed that allow the extreme weft insertion rates of the weaving machines to be translated fully into produced textile. Shifting from manual drawing-in to automatic drawing-in is the solution. Targets of automatic drawing-in are: provide just-in-time availability of the right warp(s) in the right quantity at the right time to weaving operations guarantee the right number of ends in the right sequence, colour and parallelism on every drawn warp beam reduce throughput times safeguard optimal cost of operation render reasonable and affordable investment cost with a good return for weavers A comprehensive range of Automatic Drawing-in Solutions Stäubli provides a wide range of drawing-in solutions for any kind of fabric or yarn applications. All machine versions draw warp ends directly from warp beam(s) into drop wires, healds and the reed. The highly famous DELTA series are complemented with latest technology offered by the SAFIR family. Table 2. Comparison of Stäubli drawing-in machines Criterion DELTA 100 / 110 SAFIR S80 SAFIR S30 Heald type O-, / J-, C-type J-, C-type O-type only No. of heald rails / heald frames Warp constitution Max. 16 / 20 1 beam/sheet with or without 1:1 lease, 2 layers no lease Max. 28 Max. 12 1 or 2 beams/sheets with or without 1:1 lease, up to 2 x 2 layers without lease Drawing-in speed 140 min -1 165 min -1 200 min -1 Applications Filament, Standard Shirtings, Denim High-end Shirtings, Worsteds 1 beam/sheet, no lease or with 1:1 lease 2 layers no lease Filament 408

SAFIR S80 flexibility at its best The SAFIR S80 is the universal high performance and highly flexible drawing-in machine mainly used in areas of high-end shirting materials or delicate worsted styles. The SAFIR S80 offers high configuration possibilities: Up to two warp beams / warp sheets can be drawn in with each warp having up to 2 layers Two reliable thread separation systems with either vacuum grippers (for warps without 1:1 lease) or lease units (for warps with 1:1 lease) separate any warp ends effectively A camera system detects double ends and thread colours Colour repeat control is carried out automatically Figure 3. Stäubli Drawing-in Machins SAFIR S80 SAFIR S30 - mobile automatic drawing-in machine with utmost performance The SAFIR S30 is designed for extremely high productivity especially for filament weavers with high drawing-in requirements. The unit moves along to the stationary warp during drawing-in, which is the contrary of traditional drawing-in machines where the warp beam / sheet moves along the machine. The advantage is that heavy weights filament warps sometimes weigh several tons do not need to move while precise manipulations like yarn separation are carried out. A standard configuration of SAFIR S30 consists of a mobile drawing-in unit plus 2 stretching frames, thus allowing permanent drawing in alternatively on one of the frames, while the warps are being prepared or dismantled on the second frame. The modular design of SAFIR S30 makes it easily adaptable to the needs of a mill. It integrates optimally into the material flow of a drawing-in department. Quick style change in weaving by means of Stäubli WARPLINK and UNI-PORT Upon completion of the drawing-in operation, the harness is prepared for a quick and smooth style change on the weaving machine. In order to simplify the laying in process of the complete harness into the weaving machine and to equalize the warp tension over the full 409

width a piece of plastic is welded to the warp ends in front of the reed by the welding device WARPLINK. This plastic foil does away with knotting of a knotting cloth on the weaving machine which safes a lot of time. After welding the harness is lifted away from the drawing-in machine and put down on the warp beam truck by means of UNI-PORT. Final assembly work and adjustments or possible corrections are then carried out. The Stäubli UNI-PORT handling and transport system for weaving harnesses provides safe storage of the drawn-in harness, safe transport between weaving preparation, buffer storage and weave room, and convenient transfer and laying-in of warps into the weaving machine preferably to be carried out by an electrically driven laying-in device. The weaving preparation process Figure 4. Process flow in weaving preparation A review of the multiple steps of weaving preparation shows that the potential to optimize the complete process very much depends on each single step. The effects of automation in weaving preparation are significant. ACTIVE WARP CONTROL THROUGH INNOVATIVE SHED FORMING TECHNOLOGY For more than 120 years, Stäubli has been steadily building up its strong position in providing weaving machine manufacturers with state-of-the-art shed forming technology. Whatever the weft insertion technology used on today`s weaving machines or the fabric style woven, Stäubli offers a suitable shedding solution. For plain and standard fabrics, solutions entail cam motions, negative dobbies, positive rotary dobbies as well as under-motions or drive systems including quick link systems for connecting harness frames. Part of this product range also includes special dobbies and cam motions for applications such as technical textiles, heavyduty fabrics, double-pile fabrics, carpets and many more. These machines are depending on 410

their use built with mechanical control by cams or electronic control. Common to all Stäubli cam motions and dobbies is their user-friendly operation and extremely high reliability. Figure 5. Stäubli shed forming technology & drive concept Latest Generation Cam motions for plain fabrics The latest generation of Stäubli cam motions of 1600 and 1700 series are ideally suited for weaving various plain fabrics. The 1781 model for instance is particularly suitable to produce very heavy fabrics. Both models can be used on Rapier- and Airjet weaving machines. The extremely robust construction with monobloc housing and uncompromising use of highest quality materials guarantees highest reliability and a very long service life. It is extremely easy to carry out maintenance and adjustments such as changing the cams. The housing of the 1600 range offers up to 8 lifting units whereas the 1700 series have up to 10 lifting units both with a pitch of 12 mm. Special advantages of Stäubli cam motions are: Robust monobloc housing Integrated automatic shed levelling device Quick change of cams and bevel gears Precise transmission of movement to heald frames 411

Table 6. Stäubli cam motions for plain fabrics Latest Generation Dobbies for all patterned fabrics The electronically controlled rotary dobbies of the 3rd generation S3200 type are suitable for producing patterned fabrics. The dobbies are built for very high-performance. They work on a new Stäubli rotation principle, and are the result of long engineering design experience and of intensive research and development work. The new system of selection by locking includes parts with reduced inertia, which optimizes the selection and increases the security. It guarantees a movement with absolutely zero backlash whatever the operating load or speed. Thanks to its modular and optimized design and its reading in system with fixed electromagnetic bar, noise and vibrations are reduced considerably. Its high-precision, robust construction, exceptional reliability and unparalleled service life are further enduring features of these dobbies. Special advantages of latest generation dobbies are: Robust monobloc housing Modular construction to enhance accessibility Highest quality components Considerably increased load capacity, resilience and reliability Shed opening simple to adjust Reduced maintenance Circulation type lubrication, electronically monitored Fine filter integrated in housing Integrated control box 412

Table 7. Stäubli`s latest generation of positive rotary dobbies Optimized frame drive systems The optimal use of a weaving machine and its shedding mechanics can only be reached if the system components work together in perfect harmony. Therefore the solutions of Stäubli for the shaft weaving means the supply of complete system for the shed formation, comprising the dobby or cam motion machine, the harness frame motions or drives and the connection to the harness frames. Figure 8. Frame drive systems with Stäubli Elements 413

Technical & industrial textiles Stäubli`s experience Growth projections in the market of technical & industrial textiles are massive and many weavers are gearing up for this expansion. Market studies suggest that this market segment is globally growing by 2 4 % in average per annum. Our contribution is through active warp control in warp preparation (i.e. warp tying, leasing and automatic drawing-in), shed formation (i.e. cam motions, dobbies and jacquard machines) or weaving machines (i.e. Schönherr ALPHA 500 Tech with free flight double rapiers) Stäubli products are used in basically all areas of technical & industrial textiles some examples: Agrotech (e.g. anti-hail nets, crop covers, erosion protection materials) Buildtech (e.g. tarpaulins, awnings, scaffold nets) Clothtech (e.g. interlinings, shoe components) Geotech (e.g. ground stabilization, erosion control, geosynthetics, geogrids) Hometech (e.g. carpet backings, mosquito nets) Indutech (e.g. conveyor & drive belts, bolting cloth, fibre glass, paper making felts) Medtech (e.g. gowns, drapes, wound care, sterile packaging) Mobiltech (e.g. airbags, car-aircraft-rail upholstery, automotive carpets, helmets) Oekotech (e.g. woven filters, automotive insulation) Packtech (e.g. flexible intermediate bulk containers (FIBCs), leno & laundry bags) Protech (e.g. ballistics, fire retardant apparel & fabrics, NBC suits) Sporttech (e.g. tents, artificial turf, parachute fabrics, sleeping bags) 414