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COMPANY REPORT○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○○Three companies – one projectA consortium of Bauer, Hell Gravure Systems and Kaspar Walter installed a fullyautomatic production line at Wipak WalsrodeLeft:The fully automatic productionline for printingforme manufacture atpackaging manufacturerWipak Walsrode. Thepicture shows the Multipilotpolishing machine.Right:A glimpse into the copperbath: A cylinder is copperplatedfor electromechanicalengraving. TheBallard skin method isused to achieve this.ANSGAR WESSENDORF______________________________________Ease of operation and optimumfunctionality are the key criteriawhich today’s packaging must satisfy.Aesthetic considerations arealso becoming increasingly importantbecause the customer decideswhat to buy from what the productlooks like on the supermarket shelf,a decision which is made in a matterof seconds. The message and qualityof a brand must be communicatedwithin this short period of time.Ever shorter product cycles andcalls for greater sophistication ofprint images are additional challengeswhich up-to-date packagingmust be able to face up to. WipakWalsrode GmbH & Co KG, whichprints a wide range of films with upto 11 colours in gravure, is able tosatisfy these high demands. Inhouseprepress ensures the qualityand flexibility demanded by customersin the global packagingmarket.Who is Wipak?Wipak produces flexible and durablefilms (composite and barrierfilms) for packaging for a widerange of food products and medicaland technical applications. Togetherwith European operations inFrance, UK and the Netherlands andthe North American affiliate Winpak,Wipak is part of the packagingdivision of the Finnish group WihuriOy which is headquartered inNastola/FIN. In total, the Wipakgroup has more than 20 productionsites worldwide and a workforce ofalmost 900, the German site is thegroup’s largest site in Europe. In2004, Wipak Walsrode invested in anew gravure machine and a newfully automatic production line formanufacturing gravure formes.The gravure pressIn April 2004, the T 21 packaginggravure press from Schiavi was putinto operation at Wipak Walsrode.Equipped with 11 printing units andan inline laminating station, thetotal length of the two-and-a-halfstorysystem is 38 meters. A substantialproportion of customer ordersare laminated inline. The 1400mm wide film web is guided by atotal of 430 rollers. It also has twoturnover devices, one of which canbe moved freely, making it possibleto use 11 printing units at the sametime in perfecting printing. The secondturnover device is used forcoating or applying adhesive. Themachine also features an automaticwash-up device for the ink-bearingparts installed in each printing unitand a special quick changeover systemfor gravure cylinders. An upto-dateinspection system ensuresuniform print quality over the entirerun. The Wipak group has arange of other gravure and flexographicpresses.More than justa production lineA gravure machine is only as goodas the accompanying cylinder production.In particular, the new systemmade it necessary for WipakWalsrode to expand its printingforme manufacturing capacity. Thekey factors behind the decision toinvest in a new fully automatic productionline for gravure forme cylinderswere its higher productivityand its ability to be integrated intoand closely interlinked with theproduction workflows (digital imageediting, cylinder assembly, electroplating,cylinder engraving andprinting). This should also ensurethat it can meet customers’ highquality requirements in terms of thefilms to be printed coupled withimproved response times.A consortium made up of HellGravure Systems GmbH, K. WalterMaschinenfabrik GmbH & Co. KGand Johannes Bauer Logistik-SystemeGmbH & Co. KG was awardedthe contract to install the productionline. The decision by Wipak toopt for the consortium was based onseveral different reasons. All threecompanies have many years experiencein the manufacture, logisticsand management of gravure cylinders.To avoid an overlap of expertiseand responsibilities from thevery start, the role of project managementwas assigned to a singlecompany, Bauer Logistik. The companywas responsible for this centraltask and was therefore the solecontact for Wipak for all mattersrelating to the timely completion ofthe line. This method was previouslyemployed in a project for AxelSpringer in which production linesfor illustration gravure were successfullyinstalled. The close proximityof Hell and Bauer and the 24-hour service of the consortium wereadditional benefits. »Specialistsfrom the relevant companies couldbe contacted 24 hours a day and areon site quickly to ensure that anyproblems are resolved fast,« saysJÜRGEN BROCKMANN, head of gravureforme manufacture at Wipak Walsrode.This meant that the press andproduction line could begin productionon time.One key advantage of the integrated,fully automatic productionof gravure cylinders in-house forWipak Walsrode is the ability torespond immediately to customerrequirements. Unforeseen correc-○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○62 FLEXO & GRAVURE ASIA 1-2005

○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○COMPANY REPORT○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○○ ○ ○Left:Grinding a copper surfaceon the Multipilot.Middle:The individual componentsare supplied centrallywith chemicals.tions, rush jobs or easy adaptationof printing forms to special circumstancesare now possible withoutany fuss. According to the company,this type of flexibility wouldnot be possible if they were to useexternal printing forme manufacturers.In detailIn this case, a print image can containup to 11 different colours whichmeans that a gravure forme cylinderis required for each colour. Inorder to produce the relevant printingformes, a rack serving unit retrievesthe raw cylinder to be processedfrom the store. Each individualcylinder is copper-plated, polished,engraved, chromium-platedand put into storage again until thefinished cylinder set is required forprint production. The individualproduction steps after digital processingof the print image are integratedinto an automatic productionline. The Minipilot Compactline from K. Walter consists of systemsfor electroplating and surfacetreatment designed for cylinderswith a face length of up to 1470 mm,a total length of max. 2100 mm anda circumference which not exceeding1000 mm. To be more specific,this line designed specifically forpackaging printing consists of thefollowing components:- 1 degreasing bath,- 2 copper baths,- 1 chromium bath,- 1 polishing machine (Multipilot)for copper and chromium grinding,- 1 central chemical supply,- Software and hardware for automation.The HelioKlischograph K500from Hell Gravure Systems is alsointegrated into the line for electromechanicalimaging of the coppercylinders. The automatic GeminiCompact crane and the software forthe cylinder store were supplied byBauer Logistik. Just like the presses,cylinder engraving and electroplatingoperate over four shifts.Clamping andsealing systemThe electroplating baths are fittedwith the patented, fully automaticclamping and sealing system fromK. Walter. Due to the fact that noadapters are required, in the contextof the defined cylinder specificationsthe automatic line can – intheory – be supplied almost limitlesslyfrom a single cylinder supplystation and operated without anypersonnel. This makes productionmore flexible and leads to significantsavings in staff costs and time.The separate clamping and sealingsystems ensure higher reliabilityof production. Leaks due to substandardcylinder end faces or wornsealing rubber do not damage theclamping system. Any chemicalsthat escape are fed back to thestorage tank via the overflow andsealing chamber.The shaft cylinders used areclamped using hollow cones. In theelectrolytic baths , power transmissiononly takes place via the shaftend, thus preventing damage orheating. This patented system canbe used to process almost all types ofcylinder irrespective of the propertiesof the end face. The immersiondepth of the cylinders in the chromiumand copper baths of up to60% ensures fast and consistentlyhigh-quality metal deposit on thecylinder surface.The degreasing, copper-plating,chromium-plating equipment andthe polishing machine are made ofstainless steel and therefore have along service life.Ballard skinBefore engraving copper or a chromiumlayer can be applied to the cylinderusing electroplating, it is vitalto clean the surface to improve itsadhesive properties. The shaft cylinderis placed in an electrolytic degreasingbath to achieve this. It isimperative that the layer of greaseand dirt that forms on the surface ofthe bath during the degreasing processis continually discharged to thestorage tank and saponified there.After degreasing, the forme cylinderis rinsed with distilled water,pickled with 2% sulphuric acid andrinsed again.Since the Ballard skin method isused at Wipak Walsrode, the cylinderis first treated with a separatingsolution and a copper skin for electromechanicalengraving is thenelectrolytically applied. The separatingsolution prevents the fusionof the base copper and engravingcopper so that the skin can be easilyremoved after printing and the cylindercan be processed again. Aftercopper-plating, the cylinder isground down to size and polished toa previously defined roughness value.End face processing and removingthe Ballard skin are performedaway from the line.EngravingDespite the fact that alternative methodsof imaging such as laser engraving,electrolytic etching andmasking methods are currently attractingsome attention, electromechanicalengraving remains the dominantmethod in the standardizedproduction of gravure cylinders.This is why the company opted forthe fully automatic K500 (sales ofwhich total 350 worldwide). Theengraving machine, which is integratedinto the line, is able to offera variety of special solutions toensure reproducible quality andhigh productivity. For example, fittingan automatic lubricator significantlyincreased the daily output ofengraved cylinders (average size1470 x 600 mm). Previously, thisoperation had to be carried out manually.Lubricating the copper sur-Right:The finished engraved cylinderis automatically removedfrom the engravingmachine using theGemini crane for furtherprocessing in line.FLEXO & GRAVURE ASIA 1-2005 63

COMPANY REPORT○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○○face greatly reduces the mechanicalstrain on the engraving stylus, burrcutter and slide shoe and greatlyimproves the cutting behaviour ofthe cells. According to JAN BREIHOLDT,Product Manager at Hell GravureSystems, this is currently a uniquefeature which only Hell can offer.When it is fitted with the powerfulHelioSprint engraving head, theK500 engraves around 8,000screen cells per second in the coppersurface. After imaging and electrolyticcleaning, the printing forme isprotected against wear by applyinga 6-8 µm thick chromium layersince this material is five times harderthan copper. The finished cylinderis transported to the store by ashuttle and stored there automatically.The customer’s desire to see theexisting electroplating and the sixHelioKlischograph machines integratedinto the line was also satisfied.To achieve this, a buffer was incorporatedinto the line, enablingremoval and supply of conventionallyengraved cylinders. An openingconstructed in the wall enabledthe premises of the automatic lineand conventional engraving to beinterlinked. The cylinder whenready for digital engraving is removedfrom the buffer and movedto the HelioKlischograph machine.After the imaging process, the coppercylinder is returned to the bufferfor chromium-plating. For safetyreasons, a light barrier is passedthrough each time the cylinders areput into/removed from storage, resultingin an automatic reduction inthe speed of the crane (max. 120 m/min) to walking speed. The systemcan be reset at the control panel.Surface treatmentThe Multipilot is equipped with twostone polishing and two lappingfilm polishing heads to producemore print-friendly structures forthe copper and chromium surfaces.Here the journal cylinder is alsoclamped in position using hollowcones. Simultaneous use of severalgrinding heads (simultaneous processing)leads to very short processingtimes. The operator can specifythe programme sequence for eachindividual cylinder. The strokespeed can be adjusted for the oscillatinglapping film polishing headand the feed speed, paper feed andpolishing pressure can be pre-selected.Before the start of the process,the polishing head measures thecylinder diameter to determine thecorrect cylinder speed for the specifiedcircumferential speed. The endof the lapping film is monitoredautomatically.The grinding stone thickness ismeasured before the start of grindingby the stone polishing head.This means that the stone pressure isalways the same irrespective of thethickness of the stone. The process isnot enabled if the minimum thicknessis not reached. The polishingheads are moved into position usinginfinitely adjustable servomotors.To ensure optimum grinding of thecylinder, it is possible to automaticallyreduce grinding pressure in agradual manner. Parallel to this, therotational speed of the stone canalso be reduced.Each polishing head has a headshower for which the amount ofwater can be set using a regulatingvalve. During the chromium grindingprocess, the cylinder is sprayedwith water from a spray block tocool it down. After processing, it isdried using a rubber strip and airnozzles. The storage tank for thegrinding water is located below themachine and can be pulled out forcleaning. The water required forpolishing and grinding is continuouslycirculated and filtered.Central supplyThe key component of the electroplatingline is the central chemicalsupply located in a separate room.All the media to be refilled in theelectroplating process are storedhere in concentrated form. Forsafety reasons, all the pumps in thestorage tanks automatically switchoff as soon as the entrance door isopened. This is where monitoring,metering and mixing are carried outand the individual components ofthe Minipilot Compact Line are refilledwith chemicals such as sulphuricacid, chromic acid, separatingand degreasing solutions. Thestorage tanks, which are stored onpallets, stand on a grid below whichthere is a collecting pan. This supplyconcept not only reduces the numberof errors, but also helps toachieve efficient use of personneland improved process control. Italso results in improved safety forstaff since no physical interventionLubricating the coppersurface greatly reducesthe mechanical strain onthe engraving stylus, burrcutter and slide shoe andgreatly improves the cuttingbehaviour of the cells.The automatic GeminiCompact crane for theproduction line wassupplied by Bauer Logistik.○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○64 FLEXO & GRAVURE ASIA 1-2005

COMPANY REPORT○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○○ ○ ○is now required in handling thechemicals. For example, 60% sulphuricacid from a large container ispumped into another tank for dilutionto 2%, mixed and then fed tothe degreasing unit. Due to the factthat the processes are largely automatedand the media are supplied inexchangeable containers in concentratedform, the work of staff ismainly restricted to replacingempty storage tanks and removing/reinserting the rod pumps. The chemicalsupply and the mixing is linkedto the main control station of theline where the conditions and theneed to change concentration containersare displayed and the fillingand mixing processes are monitored.CustomisedThe automation program for theproduction line developed by K.Walter in close cooperation with thecompany is specifically adapted tothe requirements of Wipak Walsrode.One component is the linecontrol for coordinating cylinderproduction in the line. The user cantake advantage of a colour displayon the screen to closely monitorproduction at all times. It also featuresthe relevant machine controlsfor the workflows of the individualcomponents in the line. Rapidchanges can be made to parametersat any time.The use of high-availability controlsystems which are tried andtested in industrial applications andthe use of standard software componentsensure optimum operationalreliability. The illustration oftechnical processes in the form ofpictograms also helps users to familiarizethemselves with the individualfunctions and makes the programmeeasier to use. In addition tothe central entry and checking ofcylinder and process data at thecontrol station, this can be performedusing the touch screens integratedinto the side panels of theunits.The special software developedby Bauer also links the cylinderstore to the production line. Theprinting formes, which weigh between100 kg and 300 kg, havetransponders at the ends of the shaftto ensure that they can be correctlyrecognized. The computer identifiesthe precise position of each individualcylinder in the fully automaticstore and guides the rackserving unit and the shuttle to theline.SummaryThe objectives in installing the fullyautomatic cylinder production systemwere to boost productivity andreduce response times while maintainingoptimum, consistent quality.The close cooperation with theconsortium of Bauer, Hell GravureSystems and Kaspar Walter meantthat these objectives were achievedwithin a short period of time.➜ www.wipak.com/company/wipak_➜ walsrode.html➜ www.hell-gravure-systems.com➜ www.kwalter.de➜ www.bauer-logistik.de