Ohm's Law – Single
Ohm's Law – Triple (Delta)
Ohm's Law – Triple (Wye)
Heat Energy Requirements
Wattage Requirements
  • Cast In Heaters for Plastics Processing

    Durex Industries is a leading edge manufacturer of cast-in heater products for the plastics processing industry.  Our products are utilized as the standard for thermal processing on plastics process equipment throughout the world.  Engineering of our cast-in products for extrusion applications is based on our years of expertise in developement of these products for the largest equipment manufacturers.

    Durex has thousands of standard tooling designs available for immediate use.  Our in-house tooling capability can rapidly produce any design available on the market.  Cast In heaters for all plastics processing applications including, air and liquid cooled barrel heaters, L-shaped heaters, vent cut out heaters, heat only cast in barrel heaters, air cooled with shroud, hollow cast nozzle heaters, and cooling jackets for cast in barrel heaters.

    Contact us for Engineering Assistance.

    More Products In This Section

    • Air Cooled Cast In Barrel Heaters
      Air Cooled Cast In Barrel Heaters
      Finned air-cooled cast-in barrel heater designs provide effective heating and cooling for plastics extrusion barrels. The fin pattern can be supplied as a standard height of 1” or manufactured to a low profile thickness for small extruders or applications requiring rapid cooling. This pattern is designed to allow the optimal…
    • Liquid Cooled Cast In Barrel Heaters
      Liquid Cooled Cast In Barrel Heaters
      Liquid cooled cast-in barrel heaters are the most common cast -in heater design used on plastics extrusion barrels. The liquid cooling tubes run symmetrical to the heater element, which provides a uniform cooling pattern across the body of the casting. This cooling function dissipates heat rapidly from the cast-in barrel…
    • L-Shaped Square Cast In Barrel Heaters
      L-Shaped Square Cast In Barrel Heaters
      The “L” shape cast-in heater design is typically used on square and rectangular extruder barrels, which utilize a twin, screw design. In most cases, the high operating temperatures in these applications require these cast-in heaters to be constructed of a bronze alloy, however aluminum alloys are used for applications, which…
    • Vent Cut Out Cast in Heater
      Vent Cut Out Cast in Heater
      Special sections of the cast-in extruder barrel such as a vent or feed throat require custom modifications to fit properly. These Vent/Cutout Cast-In Heaters are designed with element locations that maximize heater performance, but allow for special machined sections that could not be added to a standard barrel design. Have…
    • Heat-Only Cast In Heaters
      Heat-Only Cast In Heaters
      Although not a common design, heat only cast-in barrel heaters are available primarily with the stainless steel mounting strap option. This design is standardly 1” thick and can be used with all standard electrical terminations that Durex offers. The cast-in heat only design can be used on piping areas that…
    • Hollow Cast Nozzle Heaters
      Hollow Cast Nozzle Heaters
      The Hollow Cast® nozzle heater design was developed by Durex to provide a maximum efficiency-heating device for plastic molders. Utilizing casting technology, a high performance mineral insulated heater is cast-in a bronze alloy and machined for a precision fit onto the injection nozzle. Have questions? Contact us for engineering assistance.
    • High Velocity Air Cooled Shroud System
      High Velocity Air Cooled Shroud System
      Give your machine the look and performance it deserves with a High Velocity Air Cooled Shroud System! When Quality Matters................Durex Delivers   Have questions? Contact us for engineering assistance.
    • Air Cooled Cast In Heaters with Shrouds
      Air Cooled Cast In Heaters with Shrouds
      Individual shroud and blower systems can be used with finned barrel heaters as self contained systems on extruder barrels. The shrouds are manufactured as cast aluminum with bolt mounting or a hinged clamshell design fabricated from stainless steel . The internal design of throat maximizes the airflow over the finned…
    • Cooling Jackets for Cast In Barrel Heaters
      Cooling Jackets for Cast In Barrel Heaters
      Cast-in cooling jackets are manufactured for specific applications that do not require heat, but require a uniform cooling source, which can be controlled. The cooling jacket typically is 1” thick with ½” cooling tubes that are either stainless steel or Incoloy depending on the application. As with other liquid cooled…

    Engineering Data

    Cast Processes - Durocast™ perm-mold system uses steel permanent molds.  No bake sand system for special castings and short production runs.

    Machine Finish - CNC machining is performed for tight tolerances and complex configurations.  Milled finishes are provided per specification.  Belt sanding, lapping and polishing available to meet application specifications.

    Standard Machine Finish Range: 64 to 125 rms.

    Fine Finish Per Specifications: 8 to 32 rms.

    Standard Flatness: Belt sanded, .015, Milled ±.005, Lapped, .001

    Holes, Cutouts, Thermowells - Mounting or clearance holes, cutouts and thermowells, for inserting temperature measurement probes, cast-in or machined per your specifications.

    Inserts - Threaded studs, precision component parts, bushings and special design parts cast acccurately in place.

    Electrical - Resistance tolerance NEMA standard +10% -%5

    UL Component Recognition - DA Series cast in heaters are recognized per file E110394.


    • Electrical per UL 499 and UL 1030
    • Canadian Standard C22.2 No.72
    • Dimensional per specifications using
    • Coordinate Measure Machine
    • Quality standard per MIL-Q_9858A


    Installation and Maintenance Guidelines for Cast-in Heaters

    1. Always ensure that cast-in heaters are properly mounted to the application to avoid warping of flat heaters or "walking" of barrel heaters.  After the initial start-up, retighten the heater mounting system to assure complete surface contact.  Periodically check bolts or straps and tighten as required maintenance.
    2. Tighten all liquid cool connections securely to avoid rupture from internal steam pressures.  Cast in C6 fittings or brazed connections are the most reliable.  Properly maintain these connections to avoid leaks that will destroy the heater.  Do not operate hating and cooling simultaneously to avoid thermal shock of the cooling tubes.
    3. It is recommended  that water used for liquid cooling applications be treated to avoid corrosion and hard water deposits that will clog the cooling tubes over time.
    4. Install proper temperature control prior to operation of the heaters to ensure protection from over-temp situations which may damage the heater or equipment.  Periodically changing temperature sensors is good preventive maintenance.
    5. Electrical terminals must be proplerly insulated and made tightly to ensure safe operation.  All heater installations must be properly grounded.  All electrical terminations must be made per applicable Electrical Safety Codes and O.S.H.A. regulations.
    6. Do not operate the heaters outside of the voltage and temperature of the design.  This will cause the heaters to fail.
    7. ALWAYS disconnect the electrical power to heaters prior to service.


    Cast-In Heater Special Services

    • Radiograph (X-ray): Confirmation of internal element configuration and casting soundness available through x-ray.
    • Plating/Coating: Electroless nickel plating, anodize, teflon® coatings and special blasted surfaces are available per customer specifications.
    • Pressure Testing: High pressure leakage testing is done in-house per application requirements.
    • Heat Treating: Stress relieving and aging through heat treating available as required.
    • CMM Inspection: Coordinate Measuring Machine used for precision quality control of tight tolerance machining requirements.
    • Helium Leak: Detect microleakage from casting body.
    • Temperature Uniformity: Confomr heat uniformity across the finished surface.
    • Class 1000 Clean Room: Clean room assemblyand packaging per class 1000 standards.
    • Solidworks 3D Modeling: Engineering software provides 3D models of proposed or existing product designs.
    • Custom Packaging: Customer specific packaging for delicate surfaces, large multi-product shipments, or long term storage.
    • Life Cycle Testing: Life cycle test chamber for longterm testing of uniformity and performance characteristics.
    • Material Certification: Precise records and certifications on materials which require traceability to specific standards.
    • Sensor Calibration: NIST traceable calibration lab for calibration and certification of any temperature sensor requirements.
    • FEA Analysis: Preview of proposed design constructions using FEA analysis.




    Product Applications

    • Vacuum forming
    • Pressure assist forming
    • Drape and press forming
    • Barrel and sprue bushing heating
    • Hopper heating
    • Manifold heating
    • Hot runner systems



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