There are many types of heater in the market, such as band heater, cartridge heater,strip heater.The most common types of heater in injection moulding is band heater and coil heater.
Different heating methods of heaters
Resistance heating
Indirect resistance heating requires a heating element made of specialized alloy materials or non-metallic materials, which generates heat energy from the heating element and transmits it to the heated object by radiation, convection and conduction.
The materials used for the heating element of indirect resistance heating generally require large resistivity, small resistance temperature coefficient, small deformation at high temperatures and are not accessible to brittle.
Commonly used are iron-aluminum alloy, nickel-chromium alloy and other metal materials, silicon carbide, molybdenum disilicide, and other non-metallic materials.
The maximum working temperature of a metal heating element can reach 1000~1500℃ depending on the material type; the maximum working temperature of a non-metal heating element can reach 1500~1700℃.
Resistance heaters include mica heaters, ceramic heaters, brass heaters, stainless steel heaters, and cast aluminum heaters.
Infrared heating
Infrared heaters use infrared heat radiation to heat the object of the circle type of goodsAn infrared ray is an electromagnetic wave with a wavelength between 760 nanometers (nm) and 1 millimeter (mm). Most of the heat objects emit at room temperature are in this wavelength band.
Infrared heaters or heat lamps are objects with higher temperatures that transfer energy to the body with lower temperatures through electromagnetic radiation. No contact or medium is required for energy transfer between the two things, and infrared heaters can operate in a vacuum or atmosphere.
Advantages of infrared heater
- High electrical conversion efficiency. The electrical conversion rate is higher when using nickel-chromium wire than ordinary iron and aluminum resistance wire.
- Adopt the radiation heat transfer method. No medium is needed for heat transfer, not affected by contact or not, and the infrared light waves emitted can be entirely absorbed by the gun barrel.
- To achieve efficient heat insulation, use nano-level gas condensation adhesive as insulation material.
- Infrared heating ring ultra-low surface temperature can effectively reduce the workshop temperature and enhance the comfort of the workshop.
- Extremely high temperature. It is mainly limited by the maximum temperature of the infrared generator.
- Fast response time, about 1-2 seconds. The thermal inertia of the infrared radiation heating tube is minimal. It can reach about 50% of the rated power in 1~2 seconds after the power is applied and operate at total capacity after about 2~4 seconds. Especially suitable for the use of equipment with high requirements for temperature control precision like injection molding machines.
Material used for band heater
As the name suggests, band heaters are used to heat up the barrel of an injection molding machine. They are an essential piece of equipment for any plastics processing facility as they help to ensure that the plastic is melted evenly and at the right temperature. There are a few different types of band heaters, each with their own advantages and disadvantages.
Ceramic heater
A ceramic heater, assembled with nickel-chromium alloy heating wires and ceramic strips, is an electric heater that conducts heat by ceramic strips.
The ceramic electric heater adopts the way of the ceramic strip through the wire, and the power is 0.5~1.5 times higher than the standard heater.
The heating body is imported round wire ceramic flex into a spring-like penetration into the ceramic strip. The outer cover material is stainless steel, and the middle of the high-temperature insulation is cotton (aluminum silicate fiber board) to prevent temperature leakage.
The heater has the characteristics of fast heat transfer, rugged and unbreakable, high temperature does not deform, and not easy to age.
Advantages of mica heater
- Temperature does not leak out, can save electricity, the outer cover does not touch with hands, and work safely
- High power, ceramic strip through the wire power than the ordinary to 0.5 ~ 1.5 times higher
- High-temperature resistant heating wire. Fast heat dissipation, uniform heating, and high temperature stability can be used for a long time in 600-800 ℃
- Long product life, raw materials in the high-temperature aging is relatively slow
- Power deviation +5% ∽ -10%
- By voltage 1500v/50Hz sine AC voltage test, no breakdown phenomenon by 1min
- High strength, good insulation performance, large contact surface with the heated object
- Easy installation, maintenance, low cost of use
Mica heater
The mica heater is made of high-quality nickel-chromium alloy heating wire as the heating body, using natural mica as the insulating layer. The outer layer is made of high-quality stainless steel as the conduction heating layer.
The mica heater surface is generally in line with 2.5-3 watts per square centimeter. Customers can customize the automatic temperature control system according to the required power to maintain stable power and extend the service life of the heaters.
Advantages of mica heater
- Using mica as raw material is not limited by the size in production. It can be used as a small-size heater for nozzles and a heater on the barrel of a plastic machine.
- Reasonable structure
- Beautiful appearance
- Stable performance
- Even heating
- Fast heat dissipation
- Good insulation performance
- High voltage resistance
- Long service life
Brass heater
The brass heater is sealed with a brass tube. The heating body adopts imported high-temperature resistant wire and high-temperature mica plate.
The lead wire adopts a high-temperature resistant fiber wire and copper tape external way to make the lead wire wearable and durable.
Choose a copper pad and heater to connect the product’s wiring and use silver fiber welding to seal the finished product completely.
Stainless steel heater
Stainless steel heaters with stainless steel outer layer and mica or ceramic heat insulation layer can be used for the nozzle and plastic barrel heating, regardless of the standard size.
Advantages include reasonable structure, beautiful appearance, stable function, heating evenly, fast heat dissipation and high-pressure resistance.
It is widely used in plastic injection molding machines, such as injection molding machines and extrusion machines.
Aluminum heater
The cast aluminum heater is a tubular electric heating element as the heating body, the element bending molding, molding cast aluminum molding for various products.
It can closely match with the heating objects. It has uniform heating, good thermal conductivity, long service life and other characteristics.
Can add a heat insulation layer to the outside of the heater. The higher thermal efficiency can save power consumption by about 20%.
What are the types of heaters used in injection moulding machine?
People who have diy injection molding machine plans or want to make homemade injection moulding machine must want to know what types of heaters used in injection moulding machine.
Currently three types of heaters mainly used in injection moulding machine, they are barrel heaters, nozzle heaters, and hot runner heaters.
Barrel heaters
Barrel heaters provide extra heat for melting pellets in barrels. They can be a mica heater, ceramic heater and infrared heater.
The three parameters for selecting a barrel heater are the inner diameter, the height and the power.
The most efficient barrel heater is the infrared heater, while the price is the most expensive.
Nozzle heaters
Nozzle heaters provide extra heat for melting flow to prevent the hot melts from cold when injection. They can be a mica heater, ceramic heater.
The three parameters for selecting a nozzle heater are the inner diameter, the height and the power.
Hot runner heaters
The main types of hot runner nozzle heating methods include Embedded Heat Sources (Brazing) or External Heat Sources (Sleeves and Coil). So the hot runner heaters include embedded heaters, heater band sleeves, and heater coils.
Here we will not discuss the differences between the above hot runner heaters, if you want to know more, you can refer to this article UNDERSTANDING DIFFERENCES IN HOT RUNNER HEATER TECHNOLOGIES – NOZZLES.
Conclusion
We have introduced several types of heater in injection moulding. No matter which type of band heater you choose, it is important to make sure that it is the right size for your injection molding machine. If the band heater is too small, it will not be able to effectively heat the barrel. If the band heater is too large, it will be difficult to install.
When selecting a band heater, it is also important to consider the wattage. The higher the wattage, the faster the band heater will be able to heat up the barrel. However, high-wattage band heaters can be more expensive to operate.
FAQ
What are the types of heater in injection moulding?
There are many types of heater in injection moulding, including barrel heaters, nozzle heaters, and hot runner heaters.
However, according to the material used in heaters, there are ceramic heaters, mica heaters, stainless steel heaters, brass heaters, and aluminum heaters.
In addition, different heating methods can be further divided into resistance heaters and infrared heaters.
Band heaters, including ceramic heaters, mica heaters, and infrared heaters, are the three most types of heaters used in injection moulding machines.
Where to find heater bands suppliers?
The best place to find heater bands suppliers is alibaba.com. Whether you are a wholesaler or an end customer, you can find the heater supplier you are looking for.
How much is the injection moulding heater price?
Injection moulding heater price varies in size and materials. The prices of infrared heaters are the highest, while the costs of the mica heaters are the cheapest. I hope you can find the best cost-effective heaters for your injection moulding machines.