PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,

BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016

ISSN (Print) 2277—7261

A Review on Band Heaters for Heating Performance

Enhancement
Kishor M. Mahajan1. , Dr. Atul A. Patil2. , Prof. V.H. Patil3.

Assistant Professor, Department of Mechanical Engineering, GF's Godavari College of

Engineering, Jalgaon, Maharashtra, India. Email:mahajankishor87@gmail.com
Associate Professor, Department of Mechanical Engineering, GF's Godavari College of
Engineering, Jalgaon, Maharashtra, India.
Associate Professor & HOD, Department of Mechanical Engineering, GF's Godavari College
of Engineering, Jalgaon, Maharashtra, India

Abstract: Band heaters are available with Where I is the current, R is the resistance, and V is
elements of different diameters and heights, the voltage. This equation is valid for direct current
designed to heat and maintain the temperature (DC) as well as single phase alternating current (
of cylindrical parts. Heat transfer is usually AC), provided the current and voltage are express
achieved by conduction or radiation for high as root mean square (rms) values and the circuit
power heaters. They are suitable for solid being purely resistive (phase difference zero).With
heating, liquids or gases heating. Applications three phase circuit the heat generation is;
for band heaters are various they can be fitted
to nozzles or extruder barrels, process plastics QC = 3VI …...... [1]
or today’s materials such as resins that requires
high temperature or for heating conducts. They II. BAND HEARER
can also be used in plastic injection moulding as
process of materials requires high heating In IM machine, the raw material, called resin, is
power and high temperatures. usually in the form of granules. These granules

Key words: Injection Moulding, Band/Barrel

Heater, Watt Density.

I. INRTODUCTION

To bring the injection moulding machine

(IMM) or extruder machine to a functioning
temperature, heat is required; this heat brings the
machine to a proper temperature for startup and for
maintaining the desired temperature under normal
operations. There are three methods of heating the
extruder: electric heating, fluid heating, and steam
heating. The electric heating is the most common
method of heating the extruders or injection
moulding machine.
Electric resistance heaters which are
widely use in extruder/IM machines are called Figure No.Error! No sequence specified. Injection
band/barrel heaters since they are in the form of a Moulding Machine
circular band, which fits over the screw barrel of
the machine. The heat generated by the extruder is stored in a feed hopper, a bottom opened bottle
heaters is made possible by passing a certain which feeds the press with resin, shown in Figure.
amount of current through a conductor of certain The granules need to be molten to enable an
resistance, as the resistance creates barrier to the injection into the tool cavity chamber, i.e. a cavity
flow of electrons, heat is generated. The amount of that reflects the final shape of the plastic product,
heat generated is given by the equation below: the IM machine is therefore equipped with a
plasticizing unit in order to melt the resin. Initially
QC = I2R = VI = V2/ R in the plasticizing unit a screw, which rotates with
help of a motor, melts the granules. Most of the
heat is created by friction in the screws rotation but

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 PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,
BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016
ISSN (Print) 2277—7261

heating bands are often added to supplement the All full mica band heaters are designed with
heat generating. When the granules are melted the closed ends to protect against contamination.
screw inject the polymer into the cavity chamber Maximum sheath temperature is 800°F.
with an axial movement. A. Construction

In band heaters the heating element is sandwiched

between an insulating material which is a good
conductor of heat and bad conductor of electricity.
The band heaters used now a day are classified
according to the insulators used in them, as below;

1) Mica band heater

2) Ceramic band heater
3) Mineral insulated band heater [1]

III. MICA BAND HEATER

Figure No.3 Construction of Mica Band Heaters
Mica strip are usually used to insulate resistance
band heaters. These heaters are low cost but not 1. Mica insulation.
quite durable and are not very reliable. They can 2. Element ribbon.
withstand temperatures of up to 500oC and have a 3 Rust resistant steel sheath.
loading capacity of about 50 kW/m2. Recent types 4. Radial lock-up tabs.
of mica heaters can handle power densities up 5. Post terminals.
to165 kW/m2. The durability of a heater depends
on the usage and the contact between the barrel B. Features
and the surface of the heaters. Inadequate surface
contact will cause overheating and the outcome • The Standard Band Heaters are manufactured
will reduced heater life or even premature burnout in one or two piece constructions with
of the heater element. Commercially, are available maximum inside diameters of 111⁄2"and
special paste to improve the heat transfer between 221⁄2" respectively. Three or more sections
the heater and the barrel. A mica core produces a are employed when heaters of larger diameters
thin, efficient heater. Heat from the precisely are needed (as for blown film extrusion dies).
wound resistance element is quickly transferred to • Holes and cutouts are available. Maximum
the working surface for fast heat-up and response. wattage may be reduced with the addition of
Mica provides excellent dielectric strength and holes and cutouts. Drawing required for
heat transfer capability for long heater life. The specific location.
mica core is encased in a continuous corrosion
resistant sheath and formed. C. Sizes

Construction of units with inside diameters over

111⁄2" must be manufactured in accordance with
the following table.

Table No.1 Inside Diameters

Inside
Construction
Diameter Range
Two Piece Over 111⁄2" to 221⁄2"
Three Piece Over 221⁄2" to 36"
Four Piece Over 36" to 48"

The above is based on a watt density of 30 watts

per square inch of surface.
Figure No.2 Mica Band Heaters
D. Wattage

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 PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,
BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016
ISSN (Print) 2277—7261

The watt density may be varied, depending on heater control setting recorded for future reference.
operating temperature in accordance with the The material should be mixed to get an accurate
following table. temperature since the material near the outside of
the drum will heat faster than the material near the
Table No.2 Watt density center. This initial set-up should be done with the
three heat switch set on high. If the material you
Operating 0 Watts Per are heating exhibits excellent heat receptivity you
C
Temperature( ºF) Square Inch may maintain your desired temperature with the
300ºF 149ºC 40 three heat switch set on medium or low, thus
30 reducing power consumption.
400ºF 204ºC • Use on all metal drums only.
21 • For use indoors only.
500ºF 260ºC • Do not use to heat flammable materials.
316ºC 12 • Do not use in hazardous areas.
600ºF • Vent container to prevent pressure build-up.
371ºC to 10
700ºF 900ºF Max. Time vs. Temperature:
482ºC
Achieved at maximum setting, Covered 55 gallon
The following information will helps to understand drum filled with water at 70°F.
watt density in order to select the proper wattage
for our application. F. Applications

Wattage will affect the durability and performance Mica band heaters are used in Cylinders, Dies,
of band heater. To prevent heater failure, do not Drums, Holding Tanks, Injections and Blow
exceed the maximum recommended watt density Molding Machines, and Plastic Extruders.[2]
for a specific heater size.
IV. CERAMIC INSULATED BAND
𝑊𝑎𝑡𝑡𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑊 HEATERS
𝑊𝐴𝑇𝑇𝐴𝐺𝐸
= Ceramic Insulated Band Heaters are specifically
3.14𝑥𝐼𝑛𝑛𝑒𝑟𝐷𝑖𝑎𝑚𝑒𝑡𝑒𝑟𝑥𝑊𝑖𝑑𝑡𝑕 – 𝐶𝑜𝑙𝑑𝑆𝑒𝑐𝑡𝑖𝑜𝑛
designed and engineered to meet the ever
Table No.3 Length of Cold Section increasing demand for energy conservation and to
improve operation efficiency. The ceramic band
Model Cold Section heaters are capable of generating the higher
temperatures essential to process today‘s high
One-Piece 1" X Width
temperature resins. Electrical energy savings are
Two-Piece 2" X Width achieved by using a 6 mm (1⁄4") thick ceramic
Holes And Cutouts (Size + 1/2") X Width fiber insulating blanket, reducing power
consumption by 25 to 30%. Because of the low
Factors to be considered while selecting watt thermal conductivity of the ceramic fiber
density. insulation, the external surface temperature of the
 Select narrower heaters for superior heat ceramic band heater is approximately 204°C
transfer (1‖ – 2.5‖ wide). (400°F) while running the inside surface
 Select watt density according to the temperature at 649°C (1200°F). Ceramic band
operating temperature. heaters transmit heat through both conduction and
 Select the corresponding wattage for your radiation. The element winding is designed to run
application in order to prevent short at maximum temperature and heat the ceramic
cycling and inefficient operation. blocks to the point at which they radiate energy
 Consider the safe heating pattern of the into the barrel as well as conduct energy by being
heated material, the thermal conductivity, in contact with the barrel. Therefore, the fit is not
and coefficient of expansion of the as critical as in other types of bands. Ceramic band
cylinder when determining puissance. heaters have become extremely popular among
Original Equipment Manufacturers as the standard
E. Operation heaters for the barrels of plastic injection molding
machines, extruders, and blow molding equipment.
When heating a material for the first time,
the material temperature should be monitored with
a temperature indicating device and the final drum

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 PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,
BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016
ISSN (Print) 2277—7261

Resistance Tolerance: - 10%, −5%

Wattage Tolerance: -5%, −10%

C. Features
 Built-In Thermal Insulation
 Conserves Electrical Energy
 Minimum Heat Loss
 Fully Flexible For Easy Installation
 Good Temperature Uniformity
 Longer Heater Life
 Various Constructions and Terminations
 Heats Through Conduction and Radiation
 Designed to Specifications
 Reduce Heat Loss
 Conserve Energy
 Maximize Operator Comfort
Figure No.4 Ceramic Insulated Band Heater  Reduce Overall Operation Cost

A. Construction D. Features for Power Saver Construction

Standard: The basic ceramic band heater design

consists of a helically wound resistance coil made
from nickel-chrome wire, evenly stretched and
precisely strung through specially designed
ceramic insulating bricks, forming a flexible
heating mat. The ceramic heating mat along with
1⁄4" thick ceramic fiber insulation is installed in a
stainless steel housing made with serrated edges,
providing maximum flexibility for ease of
installation. This allows the use of wider band
heaters, eliminating the need for numerous narrow
width and two-piece band heaters.
Double Insulated: For situations requiring
additional insulation for lower external Figure No.5 Construction Details of Ceramic Band
temperatures and increased electrical energy Heater
savings, offers double insulated ceramic bands 1. Chrome Nickel Steel sheathing. Chrome
with full 13 mm (1⁄2") thick ceramic fiber Nickel Steel housing with serrated edges
insulation. This will decrease power consumption provides maximum flexibility for ease of
by 35 to 37% when compared to uninsulated band installation.
heaters.
2. Thermal insulation. Built-In heat saving
B. Specification Thermal Insulation standard (4mm) on all
Ceramic Bands ―Premium Heat‖ will reduce
Performance Ratings: power consumption. Further reduction can be
Maximum Temperature: - 760°C (1400°F) obtained with higher thickness insulation
Nominal Watt Density: - 3 to 7 Watt/cm2 (20 to 45 which prevents heat loss, thereby lowering
Watt/in2) energy costs.
Maximum Watt Density: - 45 Watt/cm2 (45
Watt/in2) 3. High Grade Ceramic Insulators.
Interlocking Steatite bricks designed for best
Electrical Ratings: combination of physical & dielectric strength,
Maximum Voltage: - 480 Vac per termination good thermal conductivity to heat cylindrical
Dual Voltage: -Available depending on heater parts, good for sheath temperature up to 500
configuration Deg C. provides flexibility for ease of
Maximum Amperage per Circuit:- installation on the barrel.
Lead Wire Termination: - 10 A
Screw Terminations: -25 A

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 PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,
BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016
ISSN (Print) 2277—7261

4. Ni-chrome Heating coil. Helically wound maximum current carrying capacity is strung
superior quality (60/16, 80/20) Nickel Chrome through specially Designed ceramic insulating
resistance wire designed for maximum current bricks providing even heat distribution, thus
carrying capacity is strung through specially eliminating hot spotting that can cause
designed ceramic insulating bricks providing premature heater failure.
even heat distribution, thus eliminating hot
spotting that can cause premature heater E. Technical data
failure.
Sheath material: Chrome Nickel Steel

Insulators: High Grade Steatite Ceramic

Insulators (High Temperature)

Heat Saving Thermal Insulation: Ceramic Fiber

(std.)

Heating Elements (coil):NiCr 60:16, NiCr 80:20

Connection: Fiber Glass Insulated- Metal Braided

Flexible Cable (std. 500mm long) mounted on
rigid screw post terminals

Voltage Range: 110V - 440V

Power Rating: Depending upon application

Figure No.6 Features for Power Saver plus Construction Power Tolerance: ± 10%

1. Chrome Nickel Steel sheathing. Chrome Insulation Resistance (Cold):< 20 M Ohms

Nickel Steel inner housing as well as External Sheath Temperature: Up to 500°C maximum
Insulated housing with serrated edges provides (Chrome Nickel Steel sheath)
maximum flexibility for ease of installation.
Inner Diameter: Minimum 60mm in case of
2. Additional Heat Optimizing Thermal Premium 75mm in case of Power saver & 100mm
insulation. Apart from the in built 4mm for Power Saver PLUS
Insulation A Special Additional HEAT
OPTIMIZING Thermal Insulation (16mm ) F. Temperature vs. Heat Loss
along with an AIR POCKET which preserves
the heat inside producing a uniform hot air
layer between the Heater & the outer
Insulation ( as shown in sketch above) This
helps reduce power consumption up to 30%
AND MORE (subject to working conditions)
& prevents heat loss thereby lowering energy
costs, improves Heating Efficiency for faster
productivity and simultaneously also helps
improve working atmosphere.

3. High Grade Ceramic Insulators.

Interlocking Steatite bricks designed for best
combination of physical & dielectric strength,
good thermal conductivity to heat cylindrical
parts; good for sheath temperature up to 500
Deg C provides flexibility for ease of
installation on the barrel. Figure No.7 Temperature vs. Heat Loss Graph

4. Nickel-chrome heating coil. Helically wound From above graph we can see that, the heat loss
Nickel-Chrome resistance wire designed for goes on increasing with increase in surface
temperature of the barrel for non insulated band

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 PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,
BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016
ISSN (Print) 2277—7261

heaters, as compared with the insulated band • Stainless steel screw terminals welded to an
heaters [3], [4] internal stainless steel pad effecting a positive
and secure electrical connection. The
V. MINERAL INSULATED BAND HEATER surrounding area is insulated with a high
temperature refractory cement and ceramic
insert.
• When lead wires are specified, they are also
welded to a stainless steel pad. The high
temperature mica tape lead wire, 842º F (450º
C), is ideally suited for most applications.

C. Specifications

Optional features include a sealed low profile cap

and tube termination system for low clearance
applications. The tube may be lengthened to
accommodate radius bends to clear a nozzle hex or
other obstructions. Braid and armor lead wire
protection is available. A 10‖ (25.4 cm) length is
standard. Flexible leads are 10‖ (25.4 cm)
standard. Other leads are available upon request.
Diameters from 3⁄4‖ (19 mm) up to36‖ (91.4 cm)
typical widths from 3⁄4‖(19 mm) up to6‖ (152.4
mm) maximum.
Figure No.8 Construction of MI Band Heater
D. Applications
A. Features and Benefits
• Maximum watt densities; far in excess of any The Mineral Insulated Band will consistently out-
other type of band. perform other bands in virtually any application.
• Highest application temperatures available. Its ability to withstand extremely high heat makes
• •Best possible clamping and the resulting it the best choice for the plastics industry,
improved efficiency. especially when processing engineering-grade
• Longest life available for any application and resins. Additional uses include heating pipes,
reduction of equipment downtime. chemical processing and drum heating. In addition,
• High heat transfer rates and the resulting fast Mineral Insulated Band can be modified to meet
response. the demands of virtually any special application.
• Rapid heat-up capabilities and no fear of Our engineers can utilize a variety of alternative
heater failure. features and options to customize the heater to our
• Reduced number and physical size of heaters specific needs.[5][6] [7]
required per application.
• Cost-effective performance. VI. BAND HEATER SELECTION
• Choose a Mineral Insulated Band when the
temperature of the heater will exceed 650º F Prior to selecting a band heater style for an
(343º C). application, there are a number of items that must
• Expandable or two-piece construction. be taken into consideration. These include type of
application, operational temperature, controls and
B. Material and Construction heat required to continually satisfy the application.
All band heaters have their own physical and
• Precision engineered with computer selected operational characteristics and limitations which
wound resistor element. should be reviewed prior to making a selection.
• Efficient low expansion clamping systems or Once the total wattage requirement has been
welded-to-the-sheath clamping ears. established, the number of heaters needed can be
• Optional lead and screw termination styles. determined as below.
• High temperature patented mineral insulation 𝑛𝑢𝑚𝑏𝑒𝑟𝑜𝑓𝑕𝑒𝑎𝑡𝑒𝑟𝑠
heat transfer media. 𝑡𝑜𝑡𝑎𝑙𝑊𝐴𝑇𝑇𝐴𝐺𝐸
• High temperature oxidation-resistant sheath 𝑊𝑎𝑡𝑡𝑑𝑒𝑛𝑠𝑖𝑡𝑦𝑜𝑓𝑕𝑒𝑎𝑡𝑒𝑟 𝑊 =
material commensurate with maximum • Knowing the maximum watts per square inch of
operating temperature. the heater is essential when making your selection
and can be calculated by:

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 PRATIBHA: INTERNATIONAL JOURNAL OF SCIENCE, SPIRITUALITY,
BUSINESS AND TECHNOLOGY (IJSSBT), Vol. 4, No. 2, May 2016
ISSN (Print) 2277—7261

𝐻𝑒𝑎𝑡𝑒𝑟𝐼𝐷𝑋3.14 − 1 2” 𝑋𝐻𝑒𝑎𝑡𝑒𝑟𝑊𝑖𝑑𝑡𝑕𝑟𝑠
𝑊𝑎𝑡𝑡𝑎𝑔𝑒𝑜𝑓𝐻𝑒𝑎𝑡𝑒𝑟
𝑊 𝑠𝑞 . ∈=

[8]

VII. COMPARISON OF MICA, CERAMIC

AND MINERAL INSULATED BAND
HEATERS

Table No. 4 Comparison of Mica, Ceramic and Mineral Figure No. 9 Mean Temperature vs. Watt Density Graph
Insulated Band Heaters
VIII. CONCLUSION
MICA CERAMIC MINERAL
Electric Mica Ceramic Mica After studying in details about three types of band
Insulation heaters it is seen that, band heaters without thermal
insulation causes heat loss to the atmosphere
Thermal No Ceramic Minerals
Insulation
through convection, which increases the cost of
Fiber
energy. Comparitive results shows that the mineral
Wattage 10 To 20 To 45 45 To 100 insulated band heater gives better watt densities
(W/In2) 40 (up to 100 W/in2) and lesser heat loss. Thus
Temperature 150- 150-650 340-760 mineral insulated band heaters are better band
Range (0c) 450 heaters.
Cost low high high
Durability less good better IX. REFERENCES

From the graph given below we can see that, the [1] ME 4210: Manufacturing Processes and Engineering Prof.
ceramic insulated band heaters and mica insulated J.S. Colton © GIT 2009
band heaters gives maximum watt density up to 45 [2] OMEGA HEATER CO. INC. 2059 Ninth
Ave,Ronkonkoma, NY 11779-6254
to 50 W/in2, where as the mineral insulated band [3] THERMAL CORPORATION 1264 Slaughter Road,
heaters haves maximum watt density up to 100 Madison, Alabama, USA 35758
W/in2. [4] PHP 11/12, Tankiwala Industrial Estate, Steel Made
Compound, MarolMaroshi Road, Andheri(E), Mumbai
400 059. INDIA.
[5] IDEAL HEATERS, No. 694/A, GuruwarPeth, Opposite
SBI TMPune - 411042, Maharashtra, India
[6] OMEGA Ceramic Insulated Band Heaters Manchester,
England 0800-488-488
[7] ACIM JOUANIN - 650, Rue Vulcain - Z.I. n°1 Nétreville
- BP 1725 - 27017 EVREUX Cedex
[8] TEMPCO electric heater corporation

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