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1、Chapter2Reelingandwindinghigh-speedmachineshaveonlyonewinderinspiteofthespeedincreaseofthepapermachine.Ifvibrationisaproblem,reducedspeedorspecialprogrammingofspeedcontrolsisneeded,whichwillreducewindercapacity.Also,narrowandsmall-diameterrollsareslitonthesame
2、winder,whichhasanegativeinfluenceoncapacity.Highmaximumrunningspeedandautomationlevelarecriticalsuccessfactorsforwoodfreewinders.2.4.1.4CoatedwoodfreeProblemswithcoatedwoodfreearesimilartothoseofcoatedmechanicals.Themaindifferencesare:-Higherbasisweight,better
3、strength,andstiffness(burstsandcrepewrinklesarenotcommon).-Matte,dull,andsilkgradesarealsoproduced,resultinginproblemswithglossmarking,highCOF,andvibration.-Amajorpartofproductionissheeted,whichrequiressoft,large-diameterrolls.-Airpermeabilityislow,airispumped
4、intotheroll,andwebstabilityisnotgood.Thiscanreducethemaximumpossiblerunningspeed.-Mineralcontentofthepapercanbeupto50%,whichincreasesslitterbladewear.Becausethebasisweightrangeofcoatedwoodfreegradesislarge,thewebtensionrangeisalsolargeandthehighestwebtensionsr
5、equiredareclosetoboardwebtensions.2.4.1.5ContainerboardContainerboards,i.e.,corrugatingmediumandlinerboards,arenormallywoundwithconventionaltwo-drumwinders.Boardsarebulky,weblengthinarollisshort,andboardmachineproductionishigh.Normally,thereisonlyonewinderperb
6、oardmachine.Iftheboardmachineismodern,awinderofthehighestcapacityisneeded.However,thewebisstrongandhighrunningspeedsandfastaccelerationratescanbeused.Usually,problemsencounteredareotherthanrollquality,i.e.,noise,dust,andwindercapacityrelatedtoautomationlevelan
7、davailability.Theedgetrimtransportsystemisalsocritical.Agoodsystemisequippedwithtwoseparatehigh-capacitypulpersdirectlyunderthewinderfornarrowandwideedgetrims.2.4.1.6CartonboardandgraphicalboardCartonboardsarenormallycoatedglossyormatteproducts.Bulkandstiffnes
8、sareimportantandshouldberetainedafterwindingandstorage.Matteanddullgradesaredemandingwithrespecttomarkingandbulkdecrease.Deinkedpulp(DIP)isalsousedinthemiddlelayer.DIPandcoatingare
