Barrel Heaters - Hasmak.com.tr

Hot RunnerManifold <strong>Heaters</strong>Case HistoryHot Runner Manifold <strong>Heaters</strong>Problem:An injection molding customerrequired a more efficient heatingmethod for their hot runner system toincrease start-up and throughput.A segment where hot runnersystems have been readily adoptedis in the production of plasticpreform parts (unblown bottles).This particular molder was utilizingmultiple plastic resins with melttemperature ranges of 176°C to301°C (350°F to 575°F). Thick filmtechnology heaters have anoperating range up to 500°C (932°F)and due to the overall efficiency andlow profile; they were an idealheating method for this hot runnersystem.Traditionally, the steel assemblyrequired for the hot half of a moldincludes a heated steel sectionknown as the manifold. Thisconsists of a thick steel plate withmultiple tubular heaters press-fit intomachined channels within the steel.Manifolds <strong>com</strong>prise a considerableamount of mass to ac<strong>com</strong>modatethe milled grooves for tubulars aswell as having several challenges toinsure overall thermal uniformity forthe system.Due to the mass of the manifold, thetraditional tubular heaters in thisparticular instance were not able toheat the mold quickly enough orprovide the precise level of thermaluniformity preferred by thecustomer. An additional drawbackto this method of heating was thatthe tubular heaters were difficult toremove and created a significantmess at installation and removal.148Solution:Multi-zone distributed wattage thickfilm manifold and nozzle heatersfrom Watlow.The thick film heating technologyoffered the molder multiple benefitsto meet the needs of the application.Not only did thick film provideincreased overall systemcontrollability, but also allowed forcost savings in a reduction of steelmass on the hot half as well asheater inventories.Watlow’s thick film manifoldheaters provide OEMs andmolders with the followingadvantages:Low profile design• External clamp-on design allowsfor a reduction in overall manifoldmass- no machining required fortubular channel.• Reduction in overall tool costs asmachined channels toac<strong>com</strong>modate tubular, cartridge orcable heaters are eliminated.• Low thermal mass of heater alsoresults in faster thermal responsewithin the manifold and reducedpower consumption during startupand operation.Construction• Custom CAD designs to fitexacting requirements of manifold;able to put the heat preciselywhere it is needed.• Provides uniform surface contactwith manifold.• Terminations can withstandtemperatures of up to 550°C(1022°F) and can be located innearly any location thus avoidingareas where damage could occurduring normal maintenanceprocedures.• Thick film manifold heaters do notabsorb moisture, avoidingpotential GFCI problems foundwith other heater technologies.• Contamination resistant- plasticdrool can be easily removed.• Easy replacement due to clamp-ondesign.Uniform thermal profile• Superior thermal profile in themanifold; generating bettermolding results and shorterrecovery between cycles.Reduction in heater inventory• Thick film technology allowsmolders to utilize one heater tobring steel to temperature ratherthan multiple tubular or cartridgeunits.Overall Results:The molder experienced benefits ofcost savings on steel, additionalmachining; purchasing one heater(manifold) versus multiple tubulars,experienced decreased overallpower consumption, faster systemresponse and a higher part yield.This customer has plans to orderadditional thick film technologyheaters to incorporate into additionalsystems.Custom Designs- CAD-generateddesigns allow for customization toallow for holes, fittings or nozzleareas within the manifold.Thick film technology allows hotrunner system OEMs and molders tooptimize the placement of the heatercircuit.