Coil heaters/cable heaters are electric resistance heaters which are composed of a straight or wire wound miniature helical coil resistance wire, magnesium oxide (MgO) insulation, a thin sheath metal shell (usually stainless steel that is later annealed) and a transition piece that connects the power and thermocouple leads to the heater.
NPH swaging and drawing process involved in manufacturing of coil/cable heaters compacts the magnesium oxide (MgO) insulaton that house the heating element and thermocouple wire into a solid mass, producing a rugged and durable coil/cable heater, that provides excellent thermal conductivity, dielectric strength and quick thermocouple response. Because of their low thermal mass coil heaters offer high performance that can acquire temperatures of up to 1500 ℉ along with precise temperature control. NPH coil heaters/cable heaters can be manufactured using square, rectangular or round cross section profiles.
Coil heaters or cable heaters come in a variety of shapes/configurations as required by its many applications. They can be shaped in straight lengths, spirals and other patterns similar to those found with tubular heater elements. Frequently though, custom (bespoke) coil heaters are configured as low profile small diameter, high performance nozzle heaters used on injection molding machine nozzles and sprue bushings.
Other uses for coil heaters include using them as cartridge heaters where irregular size mold or platen bores are found. A straight, round cable heater can snake through a sealing bar in packaging and sealing equipment installations. Heat tracing, rod, pipe and tube heating are among other areas where coil heaters are used. They can also be cast into metal or welded onto machine component parts. All of our coil heaters are custom (bespoke) made and are CSA and UL recognized.
National Plastic Heaters’ Bespoke Coil/Cable Heaters Offer a wide range of performance enhancing options including:
- Outside sheath to improve heating efficiency
- Inside/Outside sheath with sealed end rings to prevent contaminates shortening heater life
- Embedding in brass to create high thermal mass surrounding the heater improving high
- Temperature performance and heater life
- Moisture resistant transition head
- High temperature lead and potting options
- Flexible cold section
- Wide variety of standard and custom lead exit options
National Plastic Heaters’ Custom (Bespoke) Coil and Cable Heaters: Benefits and Advantages:
- Custom ( Bespoke) wound from straight stock for same day shipments
- Flexible cold section
- Higher watt density than a cable heater
- Resistance wire centered for more repeatable heat profile
- Sealed transition head for moisture resistant applications available
- NPH can wind coil heaters from stock and ship same day or build to order in 7 business days
Technical Specifications for NPH Custom Coil and Cable Heaters:
- Thermocouple: Integrated type J or type K
- Profile: 2.5mm(.098″) Thick X 3.4mm(.134″) Wide
- Maximum Sheath Temperature: 1382 deg. F
- Sheath Material: Cr-Ni Steel
- Maximum Total Straight Length: 3000mm (118.11″)
- Length Tolerance: Heated +/-1%; Unheated +/- 2.5%
- Maximum Voltage: 250VAC
- High Voltage Stability: 800 VAC
- Wattage Tolerance: +/-10% (contact hotset for special)
- Minimum Bending Radius: 6.35mm(.250″)
- Watt Density: 38.7 Watts/In2
- Insulation Resistance: >=5M Ohm @ 500 VDC (cold)
- Leakage Current: <= 0.1mA @ 253 VAC (cold)
- Length of Unheated Zone: 65mm(2.56″); 25mm(1.00″) Transition Head
- Standard Connection from Stock: 48″ Teflon Leads.