Coil / Cable / Nozzle Heaters

Build-to-Order Heating Solutions

The Right Thermal Solution for You

Precise. Durable. Versatile. Nexthermal Coil Heaters deliver the performance you need.

What is a Coil Heater?

Coil heaters are also referred to as cable heaters, hot runner nozzle heaters, spring heaters, hot sprue heater, or micro tubular heaters. Though often found in a spiraling or winding shape, a hot runner coil heater is not named after the shape of its exterior; the name refers to the resistance wire inside the heater that has a small winding pattern throughout the length of the heater.

Coil Heater Applications

  • Plastic Injection Molding
    A Nexthermal coil heater’s strength is its ability to be shaped specifically for your nozzle heating applications. The heat can be directed to specific sections of the nozzle by adjusting the winding tightness in different sections.
  • Mass Spectrometry
    Nexthermal coil heaters are used in a broad range of scientific and medical applications. Small and light-weight coil heaters can be used to change liquid samples into vapor.
  • Food / Tray Seal Packaging
    Our coil heaters generate heat evenly along the heater, perfect for creating even seals in any type of tray sealing application including non-standard shapes.
  • Rubber Injection Molding
    Nexthermal can manufacture round coil heaters to be fitted into a plate used for rubber injection molding. In some cases, we have even designed the plate to gain optimal performance and energy efficiency from the heater, resulting in a longer heater life and faster throughput.

Nexthermal Coil Heaters

  • Range from Micro Mini to Maxi Coil heaters so you can choose the right size and wattage capability for your application
  • Includes internal thermocouple options or may be used with external thermocouples
  • May be wound to directly fit a nozzle, embedded in a thermal mass for nozzle, formed into a grove for three dimensional heating, or can work as an easy-to-remove cartridge heater alternative
  • May be manufactured with longer cold sections to allow higher temperature applications to utilize flexible leads and moisture resistance

Coil Heater Profile Comparison

Coil Heater Profile Comparison - Round
Round
Warranted Watt Density: 39 W/in²

Ideally suited for pressed in groove applications, highly flexible heater with integrated thermocouple

Coil Heater Profile Comparison - Flat
Flat
Warranted Watt Density: 48 W/in²

High surface contact for good heat transfer to the tool. Can be used with a clamping strap or Constrictor

Flat Pressed in Brass Coil Heater - Nexthermal
Flat - Pressed in Brass
Warranted Watt Density: 96 W/in²

The benefit of good heat transfer and higher allowed watt density for higher temperatures

Mini Pressed in Brass Coil Heater
Mini - Pressed in Brass
Warranted Watt Density: 80 W/in²

Highly adaptable small format heater that can be designed to provide good heat density as well as flexible design

OD Sheath Coil Heater
OD Sheath
Warranted Watt Density: 65 W/in²

Coil heater option which increases the heat energy reflected into the tool, increasing its efficiency by about 20%. It is designed to slip fit the heater onto the tool. The Constrictor is the improved option if you are considering this.

Wind from Stock

2.5 mm x 3.4 mm (0.098″ x 0.134″) Flat Coil Heater (240V)

Standard 1000 mm (39.4″) Teflon and PTFE Leads Available w/ Ungrounded TC
Heated Length (in)
Total Length (in)
Watts

10.5
12.5
16
19
22
26
30
36
38
42
45
75.28
79
86.6

14.5
16.5
20
23
26
30
34
40
42
46
49
78.84
82.56
90.16

215
250
325
390
470
520
610
630
700
800
850
1050
1150
1300

Specifications

Micro Mini
Mini Flat
Mini Round
Square
Flat
Round
Maxi
Profiles

0.039″ x 0.067″
1.0 mm x 1.7 mm

0.051″ x 0.090″
1.3 mm x 2.3 mm

∅ 0.055″ or ∅ 0.070″
∅ 1.4 mm or ∅ 1.8 mm

0.118″ or 0.128″ 
3.0 mm or 3.25 mm

0.071″ x 0.126″
0.089″ x 0.165″
0.098″ x 0.134″
1.8 mm x 3.2 mm
2.2 mm x 4.2 mm
2.5 mm x 3.4 mm

∅ 0.118″
∅ 0.125″
∅ 0.126″
∅ 0.157″
∅ 3.0 mm
∅ 3.18 mm
∅ 3.2 mm
∅ 4.0 mm

0.181″ x 0.338″
4.6 mm x 8.6 mm

Minimum Inside Diameter

0.236″
6.00 mm

0.236″
6.00 mm

0.236″
6.00 mm

0.472″
12.00 mm

0.472″
12.00 mm

0.472″
12.00 mm

0.79″
20.0 mm

Voltage

120 V / 240 V

120 V / 240 V

120 V / 240 V

120 V / 240 V

120 V / 240 V

120 V / 240 V

120 V / 240 V / 480 V

Minimum Bending Radius

0.118″
3.0 mm

0.118″
3.0 mm

0.118″
3.0 mm

0.236″
6.0 mm

0.236″
6.0 mm

0.236″
6.0 mm

0.393″
10.0 mm

Straight Heated Length

112.2″
2800 mm

112.2″
2800 mm

112.2″
2800 mm

86.6″
2800 mm

86.6″
2800 mm

86.6″
2800 mm

86.6″
2500 mm

Thermocouple Availability (Type J / Type K)

External

External

External

Internal or External

Internal or External

Internal or External

Internal or External

Material Options

SS321 or Nickel

SS321 or Nickel

SS321 or Nickel

SS321

SS321

SS321

SS321

Profile
0.039″ x 0.067″
1.0 mm x 1.7 mm
Minimum Inside Diameter
0.236″
6.00 mm
Voltage
120 V / 240 V
Minimum Bending Radius
0.118″
3.0 mm
Straight Heated Length
112.2″
2800 mm
Thermocouple Availability (Type J / Type K)
External
Material Options
SS321 or Nickel

Profile
0.051″ x 0.090″
1.3 mm x 2.3 mm
Minimum Inside Diameter
0.236″
6.00 mm
Voltage
120 V / 240 V
Minimum Bending Radius
0.118″
3.0 mm
Straight Heated Length
112.2″
2800 mm
Thermocouple Availability (Type J / Type K)
External
Material Options
SS321 or Nickel

Profile
∅ 0.055″ or ∅ 0.070″
∅ 1.4 mm or ∅ 1.8 mm
Minimum Inside Diameter
0.236″
6.00 mm
Voltage
120 V / 240 V
Minimum Bending Radius
0.118″
3.0 mm
Straight Heated Length
112.2″
2800 mm
Thermocouple Availability (Type J / Type K)
External
Material Options
SS321 or Nickel

Profile
0.118″ or 0.128″ 
3.0 mm or 3.25 mm
Minimum Inside Diameter
0.472″
12.00 mm
Voltage
120 V / 240 V
Minimum Bending Radius
0.236″
6.0 mm
Straight Heated Length
86.6″
2800 mm
Thermocouple Availability (Type J / Type K)
Internal or External
Material Options
SS321

Profile
0.071″ x 0.126″
0.089″ x 0.165″
0.098″ x 0.134″
1.8 mm x 3.2 mm
2.2 mm x 4.2 mm
2.5 mm x 3.4 mm
Minimum Inside Diameter
0.472″
12.00 mm
Voltage
120 V / 240 V
Minimum Bending Radius
0.236″
6.0 mm
Straight Heated Length
86.6″
2800 mm
Thermocouple Availability (Type J / Type K)
Internal or External
Material Options
SS321

Profile
∅ 0.118″
∅ 0.125″
∅ 0.157″
∅ 1.8 mm
∅ 2.2 mm
∅ 2.5 mm
Minimum Inside Diameter
0.472″
12.00 mm
Voltage
120 V / 240 V
Minimum Bending Radius
0.236″
6.0 mm
Straight Heated Length
86.6″
2800 mm
Thermocouple Availability (Type J / Type K)
Internal or External
Material Options
SS321

Profile
0.181″ x 0.338″
4.6 mm x 8.6 mm
Minimum Inside Diameter
0.79″
20.0 mm
Voltage
120 V / 240 V / 480 V
Minimum Bending Radius
0.393″
10.0 mm
Straight Heated Length
86.6″
2500 mm
Thermocouple Availability (Type J / Type K)
Internal or External
Material Options
SS321

Lead Protection

Fiberglass Sleeving

Fiberglass Sleeving

Provides lead protection against chaffing on tools/machinery, as well as low-level resistance against moisture and some chemicals. Also provides a cleaner appearance, by bundling the leads together.

Braided Metal Sleeving

Braided Metal Sleeving

Offers a high level of protection against mechanical damage. Sometimes used in place of conduit, when a lot of bends are required. If gas-proof armor cable is used, a higher level of moisture and corrosion resistance can be achieved.

Flexible Armor Cable

Flexible Armor Cable

Coil heater option which increases the heat energy reflected into the tool, increasing its efficiency by about 20%. It is designed to slip fit the heater onto the tool. The Constrictor is the improved option if you are considering this.

Exit Options

Nexthermal Coil Heaters Exit Option 1
Exit 1
Nexthermal Coil Heaters Exit Option 2
Exit 2
Nexthermal Coil Heaters Exit Option 3
Exit 3
Nexthermal Coil Heaters Exit Option 4
Exit 4
Nexthermal Coil Heaters Exit Option 5
Exit 5
Nexthermal Coil Heaters Exit Option 6
Exit 6
Nexthermal Coil Heaters Exit Option 7
Exit 7
Nexthermal Coil Heaters Exit Option 8
Exit 8
Nexthermal Coil Heaters Exit Option 9
Exit 9

Constrictor

Constrictor Group
Constrictor Attachment
Nexthermal Coil Heaters - Constrictor

Precise. Durable. Versatile. Nexthermal Coil Heaters deliver the performance you need for plastic injection molding, mass spectrometry, top seal packaging, food production, and your next innovation.

The Constrictor optional accessory is a retaining system that expands and slides over the open coil heater after the heater has been installed on a tool, holding tension on the heater during operation.  The advantage of this accessory is it counters the natural expansion of the coil heater during thermal expansion.  By doing so the customer can have several advantages

  • Faster recovery time for the tool from better heat transfer
  • Better temperature feedback to the thermocouple (if internal TC is used)
  • Lower heat loss to the environment as the alloy has a high degree of thermal reflectivity back into the tool, which improves the energy efficiency

Available in a wide range of standard diameters, and available in standard length of 30mm to allow for positioning on the tool.  In cases where the tool being heated is longer than 60mm, we have found its best used at the end zones of the tool and leave the center open, which reduces the heat buildup in the center of the tool and can thermally damage the tool or product being processed. 

In the following graph testing a hot runner nozzle the dark blue line represents the performance difference using the Constrictor over the standard open coil (red line) and another option we offer of a Pressed On Sheath (light blue).  In the test the tool had a Constrictor placed on the first 30mm and the final 30mm, leaving the center open coil.  The Constrictor allowed for higher tip temperatures, better thermocouple accuracy and better manifold temperature – while allowing the plastic to be protected from heat related damage between molding cycles in the center of the nozzle.

The Constrictor can be installed using our hand tool, or by a standard snap ring plier as well if available to the installer and care is taken not to over expand during installation which can distort the spring tension that it’s sized to hold.

Coil Heater Assemblies

Hotlock

Hotlock

Self-contained heater with integrated locking ring used for nozzle heating.

Axial Clamp

Braided Metal Sleeving

Offers a high level of protection against mechanical damage. Sometimes used in place of conduit, when a lot of bends are required. If gas-proof armor cable is used, a higher level of moisture and corrosion resistance can be achieved.

Flexible Armor Cable

Flexible Armor Cable

Coil heater option which increases the heat energy reflected into the tool, increasing its efficiency by about 20%. It is designed to slip fit the heater onto the tool. The Constrictor is the improved option if you are considering this.

For more information about our coil heaters, cable heaters, and injection mold heater options, give us a call today at (269) 964-0271 or send an email to sales@nexthermal.com.

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FAQ's

What are common applications for coil heaters?

Coil heaters are used in many applications in varying industries such as plastic and rubber injection molding, thermoforming, hot-runner systems, and food seal packaging. The key distinction to this product is a outside-in heating approach where flexibility to different geometries are needed.

What types of metal are used in constructing a coil heater?

The Micro Mini and Mini Flat can be constructed in either SS321 or Nickel. The rest of our coil heaters are made in SS321

How does a coil heater work?

A coil heater is a resistance type of electric heater. Current flow is restricted by the special alloy wire and converted to heat energy. In a coil heater the resistance wire is suspended within a electrically insulating and thermally conductive ceramic. Then entire assembly is fully soft annealed for formability into shapes and grooves as the application requires.

What are the temperature limits of a coil heater?

Coil heaters are limited the same as cartridge heaters. The heated zone is rated to 1472F (800C), the lead wires and transition head are limited based on final design requirements.

Can a thermocouple be built into a coil heater?

For our square, flat, round, and maxi types, a Type J or Type K thermocouple may be built into a coil heater. The thermocouple can be positioned so that the sensing point can be anywhere along the length of the heated zone. Ungrounded or grounded styles are also possible depending on what temperature you are trying to best read.

How do I select the right coil heater for my application?

The application will dictate the appropriate final design. If there are process contaminates you might consider an encased design to protect the heater, high temperatures or high watt densities will require holding features to counter for thermal expansion and provide efficient heat transfer.

Are coil heaters available in metric sizes?

Yes. Coil heaters are available in both metric and imperial sizes. Please check our size chart for available dimensions.

What are the lead times of custom coil heater?

Lead times for custom coil heaters are 12-15 business days. Please contact your sales rep to receive an accurate ship date.

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