Barrel Heaters - Hasmak.com.tr

Hot RunnerManifold <strong>Heaters</strong>Tubular Milled GrooveWatt DensityThe wattage dissipated per squareinch of the element sheath surface(defined as Element Watt Density) iscritical to the proper heating of theapplication and to the life expectancyof the heater. This is calculated withthe following formula:146Watt Density (W/in 2 ) =Element Wattageπ Element Dia. Element Heated LengthConstructionTubular heaters are a versatile andwidely used source of electric heatfor hot runner manifold applications.They can be designed in a widerange of electrical ratings, diameters,lengths, terminations and sheathmaterials. Important and usefulcharacteristics of tubular heaters arethat they can be formed into virtuallyany manifold geometry.Though we re<strong>com</strong>mend the use ofheat transfer cement for maximumheater performance and long life,proper groove fit even without HTCcan still assure good heater performanceas well as easier installation.With or without heat transfer cement,use the graph above to select thesheath watt density or the tightestgroove fit for your hot runner moldapplication.Optimum groove fit without heattransfer cement is determined byplotting the intersect point betweenthe required sheath watt density andthe Delta temperature. If the Delta Tis known, simply subtract the moldtemperature from the maximumDelta Temperature—°F1200110010009008007006005004003002001002Milled Groove Sheath Watt Density and Groove FitSheath Watt Density—W/cm 24 6 8 10 12 14 16Delta Temperature is Difference BetweenSheath and Steel Block Temperatures1.65 mm (0.065 in.) Groove Fit Without HTC0.18 mm (0.007 in.) Groove Fit Without HTC1.65 mm (0.065 in.) Groove Fit With HTC10 20 30 40 50 60 70 80 90 100 110 120Sheath Watt Density—W/in 2HTC = Heat transfer cement537°C (1000°F) sheath temperature.Any <strong>com</strong>bination of watt density andgroove fit which results in a Delta Tbelow the re<strong>com</strong>mended maximumwill maximize heater life. Conversely,the greater the Delta T, the shorterthe heater life.Common Diameters6.6 mm (0.260 in.)8 mm (0.315 in.)8.5 mm (0.335 in.)9.5 mm (0.375 in.)10.9 mm (0.430 in.)Re<strong>com</strong>mended watt density: 40 to 70 W/in2600500400300200100Ordering InformationTo order a replacement heater,specify the existing Watlow codenumber.To order a heater for yourapplication, specify:• Type of application• Operating temperature• Volts• Watts• Termination• Bend configuration anddimensions• Groove cross section dimensions• Diameter• Sheath material• Hot and cold junctionsDue to precision formingrequirements, please provide adetailed drawing or electronic file.0Delta Temperature—°C