Plastic Machinery Band Heater Overview
Heater band, also known as electric heating coil or heating coil. It uses electric heating alloy wire as the heating material and mica soft plate (sometimes ceramic core) as the insulation material. Used to convert electrical energy into thermal energy to heat objects, it is a form of electrical energy utilization. Compared with general fuel heating, electric heating can achieve higher temperatures (such as arc heating, which can reach temperatures above 3000 ℃), making it easy to achieve automatic and remote temperature control. Electric heating can directly generate heat inside the heated object, resulting in high thermal efficiency and fast heating speed. It can also achieve overall uniform heating or local heating (including surface heating) according to the heating process requirements. During the electric heating process, there is less waste gas, residue, and smoke generated, which can keep the heated object clean and not pollute the environment. Therefore, electric heating is widely used in production, scientific research, and experimental fields. Widely used in the field of plastic processing machinery
Heater Band Working Theory
The high-frequency high current flows towards a heating coil that is wound into a ring or other shape (usually made of copper tubes). As a result, a strong magnetic beam with instantaneous polarity changes is generated within the coil. When metal and other heated objects are placed inside the coil, the magnetic beam will penetrate the entire heated object. In the opposite direction of the heating current inside the heated object, a corresponding large eddy current will be generated. Due to the presence of resistance within the heated object, a significant amount of Joule heat is generated, causing the object's own temperature to rapidly rise. To achieve the purpose of heating all metal materials.
Resistance Heating Coil
Using the Joule effect of current to convert electrical energy into thermal energy to heat objects. It is usually divided into direct resistance heating and indirect resistance heating. The power supply voltage of the former is directly applied to the heated object, and when there is current flowing through it, the heated object itself is electrically heated by the ironing machine
Fever in the stool. The object that can be directly heated by resistance must be a conductor, but it must have a high electrical resistivity. Due to the fact that heat is generated from the heated object itself, it belongs to internal heating and has a high thermal efficiency. Indirect resistance heating requires heating elements made of specialized alloy or non-metallic materials, which generate heat energy and transmit it to the heated object through radiation, convection, and conduction. Due to the fact that the heated object and heating element are divided into two parts, the type of heated object is generally unrestricted and easy to operate.
The materials used for heating elements in indirect resistance heating generally require high electrical resistivity, low temperature coefficient of resistance, minimal deformation at high temperatures, and less susceptibility to embrittlement. Commonly used metal materials include iron aluminum alloys, nickel chromium alloys, and non-metallic materials such as silicon carbide and molybdenum disilicide. The maximum working temperature of metal heating elements can reach 1000-1500 ℃ depending on the type of material; The maximum operating temperature of non-metallic heating elements can reach 1500-1700 ℃. The latter is easy to install and can be replaced in a hot furnace, but it requires a pressure regulating device during operation and has a shorter lifespan than alloy heating elements. It is generally used in high-temperature furnaces, places where the temperature exceeds the maximum allowable working temperature of metal heating elements, and certain special occasions.
Infrared Heating Band
By using infrared radiation, objects absorb infrared radiation and convert it into heat energy, which is then heated.
Infrared is an electromagnetic wave. In the solar spectrum, located outside the red end of visible light, is an invisible radiation energy. In electromagnetic spectrum, the wavelength range of infrared is between 0.75 and 1000 microns, and the frequency range is 3 × 10~4 × Between 10 hertz. In industrial applications, infrared spectra are often divided into several bands: 0.75-3.0 microns are in the near-infrared region; 3.0-6.0 microns are in the mid infrared region; 6.0-15.0 microns are in the far infrared region; 15.0-1000 microns are in the extremely far infrared region. Different objects have different abilities to absorb infrared radiation, and even the same object has different abilities to absorb infrared radiation of different wavelengths. Therefore, when applying infrared heating, it is necessary to choose a suitable infrared radiation source based on the type of object being heated, so that its radiation energy is concentrated within the absorption wavelength range of the heated object, in order to achieve good heating effect.
Electric infrared heating is actually a special form of resistance heating, which uses materials such as tungsten, iron nickel, or nickel chromium alloy as radiators to create a radiation source. After being powered on, thermal radiation is generated due to its resistance heating. The commonly used electric infrared heating radiation sources include lamp type (reflective), tube type (quartz tube type), and plate type (planar). Lamp type is an infrared light bulb that uses tungsten wire as the emitter and is sealed in a glass shell filled with inert gas, similar to a regular lighting bulb. After being electrified, the radiator generates heat (at a lower temperature than a typical lighting bulb), thus emitting a large amount of infrared radiation with a wavelength of about 1.2 micrometers. If a reflective layer is coated on the inner wall of the glass shell, infrared radiation can be concentrated in one direction, so a lamp type infrared radiation source is also known as a reflective infrared radiator. The tube of a tube type infrared radiation source is made of quartz glass with a tungsten wire in the middle, so it is also called a quartz tube type infrared radiator. The wavelength of infrared emitted by lamp and tube types ranges from 0.7 to 3 microns, and their working temperature is relatively low. They are generally used for heating, baking, drying, and infrared therapy in light and textile industries, as well as in medical applications. The radiation surface of the plate type infrared radiation source is a flat surface composed of flat resistance plates. The front of the resistance plate is coated with materials with high reflection coefficients, and the back is coated with materials with low reflection coefficients, so most of the heat energy is radiated from the front. The working temperature of the plate can reach over 1000 ℃ and can be used for annealing of welds in steel materials, large-diameter pipelines, and containers.
Due to its strong penetration ability, infrared radiation is easily absorbed by objects, and once absorbed by objects, it immediately transforms into thermal energy; The application of infrared heating has developed rapidly due to its low energy loss before and after heating, easy temperature control, and high heating quality.
Ceramic Band Heater
The high-temperature resistant ceramic electric heating coil is not made by the general mica wire bending method, but by the ceramic strip threading method, so the power of this product is 0.5-1.5 times higher than that of ordinary ones. The heating element is made of imported round wire ceramic twisted into a spring shape and inserted into a ceramic ring. The outer cover is made of Japanese stainless steel, and the middle is made of high-temperature insulation cotton (aluminum silicate fiber board) to prevent temperature leakage. Ceramic strips are high-frequency ceramics that have the characteristics of fast heat transfer, hardness and non fragility, high temperature non deformation and non aging. Ceramic heating ring brief performance: It is mainly suitable for extrusion, casting, and downward punching mechanical operations, with a temperature of up to 450 degrees and a maximum surface load of 6.5W/cm. It is characterized by long service life, high temperature resistance, energy consumption reduction of 30%, high insulation, and is the most suitable electric heating product for extruders, injection molding machines, and blown film machines. Ceramic heating rings have the advantages of easy installation, fast heat transfer, good insulation, and production that is not limited by models and specifications. High working temperature, fast heating, high thermal efficiency, pollution-free, uniform and accurate heating. The specific advantages are as follows: 1. It has flexibility. For example, when heating containers or pipelines, it can be bent into an arc or circular shape and wrapped on the surface for heating. For heating large workpieces, local wrapping can be used, and large-area workpieces can be covered by flat laying. In addition, it can be suitable for heating workpieces of various geometric shapes. 2. High working temperature, fast heating, high thermal efficiency, pollution-free, uniform and accurate heating, and can achieve automatic control. 3. High mechanical strength, good thermal insulation performance, large contact surface with heated objects, and long service life. 4. Easy to install and maintain, with low usage costs. Even if the internal heating material is damaged, the external ceramic components can still be reused.
Mica Stainless Steel Band Heater Coil
Mica heating ring is composed of high-quality nickel chromium alloy heating wire as the heating element, natural mica as the insulation layer, and high-quality stainless steel as the conductive heating layer on the outer layer. Mica heating ring can be mechanically processed into rings, plates, and various irregular products according to customer needs. The surface of the mica heating ring is normally within 2.5-3 watts per square centimeter. Customers should use an automatic temperature control system according to the required power range to maintain normal power and protect the service life of the heating ring. Performance advantages of stainless steel mica electric heating ring: Due to the use of stainless steel and mica as raw materials, this product is not limited by specifications in production. It can be used for small-scale heating of nozzles and for heating on plastic machine barrels. It has the characteristics of reasonable structure, beautiful appearance, stable performance, uniform heating, fast heat dissipation, long service life, good insulation performance, and high voltage resistance. Application scope of stainless steel mica heating ring: widely used in plastic molding machinery such as injection molding machines and extruders.
Cast Aluminum Band Heater
Aluminum heating coils can be divided into die casting and casting casting. In situations with a large number of specifications and sizes, casting technology is generally used. During casting production, high-purity aluminum blocks are used, which are transformed from solid to liquid state by a high-temperature furnace. They are then injected into a mold with installed heating tubes, cooled and formed, and then precision processed to produce. The normal thickness of cast aluminum heating coils is 20mm and 25mm, and the inner wall of the 25mm wall thickness heating coil is designed with a concave convex wind groove structure to prevent excessive temperature of the internal heating tube during use. For example, when the temperature is high, wind cooling or water cooling can be used on the inner wall to quickly reach the standard temperature for use. At the same time, the heating ring is basically divided into two semicircles by half, and then fixed and installed with fixing bolts. The temperature measurement chamber is mainly used in situations where temperature signals need to be collected. Usually, holes are opened on the curved surface of the cast aluminum heating ring according to its design size for installing thermocouples.
Cast Copper Band Heater
After precision processing, it can tightly adhere to the heated body, and the surface load of the cast aluminum heater can reach 2.5-4.5w/cm2, with a maximum working temperature between 400-500 ℃; The surface load of the copper casting heater can reach 3.5-5.0w/cm2, and the maximum working temperature is between 600-700 ℃; The surface load of the copper casting heater can reach 4.5-6.0w/cm2, and the maximum operating temperature is between 800-850 ℃. Metal casting heater is an efficient and uniform heat distribution heater made of metal alloy with excellent thermal conductivity, ensuring uniform hot surface temperature and eliminating hot and cold spots in the equipment. It has advantages such as long service life, good insulation performance, strong mechanical performance, corrosion resistance, and anti magnetic field. Adding insulation devices to the external heat dissipation surface and sintering infrared radiation on the internal heat dissipation surface can save 35% of electricity consumption.
