The belt heater, as shown in Figure 3, for the extruder has been specially manufactured. The specification of the belt heater used is 220 volts and 200 watts. The belt heaters have been adapted to the barrel with diameters of 35 mm and 40 mm. The heaters were connected to the solid state relay (Fig. 3), which is controlled by a PID controller (Fig. 3) for temperature control. The PID acts as an ON/OFF device that turns off the heating when the target heat is reached, and otherwise turns on the heating further. The heater is equipped with a clamping device that has a lid screw for easy and even adjustment of the heating in the barrel.
Belt heaters are designed to attach to an outer or inner cylindrical surface. Belt heaters often have higher wattage densities, which allows for rapid heating and high operating temperatures. They usually contain terminal kits that facilitate installation. Belt heaters are used for injection molding drums and nozzles, extrusion and molding presses, pipe heating, heat treatment and autoclaves, food industry and other applications. A thin layer of the thermally conductive “high” MI material is used to electrically insulate the element wire from the inner diameter of the heater cover. A thicker, “lower” thermally conductive layer supports the elemental wire by directing the heat inwards to the part to be heated.
The specially developed tightening clamp provides a complete and uniform closure for maximum heat transfer. A variety of terminal types and locations are possible to meet any installation need. Mica tape heaters consist of a resistive wire or an insulated tape between two mica plates. This assembly is protected by an aluminum sheet with high corrosion and heat resistance.
Mi-Plus belt heaters are suitable for temperatures up to 760 °C (1400 °F) and wattage densities of up to 23.25 W/cm2 (150 W/in2). Ceramic insulated belt heaters can meet the requirements for energy saving and operational efficiency. They are able to produce higher temperatures, which are essential for processing current resins. However, these standard variants and terminations of the Duraband heater do not represent the scope of our capabilities. Star Process and Controls’ technical staff, who have many years of experience in thermal processing and temperature control, can help you develop the right belt heater for your specific application. By far the most common culprit for the failure of belt heaters is environmental pollution.
If you have any questions or concerns about heaters, contact the team at Hi-Watt, Inc. for assistance. Plastics processing requires high operating temperatures and fast production rates. Omega has developed its ceramic belt heaters to meet these requirements. These heaters are in fact high-temperature electric furnaces that allow very efficient heat transfer through radiation, conduction and convection. The built-in insulation minimizes unwanted temperature changes throughout the run.
After the wires are fastened, the outer sleeves are attached and the belt heater is wound and shaped to the desired diameter. Mica belt heaters are very often used in the plastics industry for injection extrusion Mica Band Heater Manufacturer and blow molding. The heater sits on cylindrical metal pipes or a barrel to heat the contents of a solid onto molten liquid. Belt heaters are thin and therefore ideal for effective heat transfer.
Rectangular bands are used when there is a rectangular die or shape in which a belt heater does not fit. Configuration 403, 415 or 417 and each configuration has several different options that can be added or changed according to your needs. In the barrel and in the hot corridor and the shear effect of the snail. Dryers offer a very high efficiency (up to 98%) when heating, as they are well insulated and heat the resin directly. The shear effect and the heating tapes of the cylinder, on the other hand, heat the resin less efficiently (about 60%). For the processor, this means that the higher the running inlet temperature, the less power the process requires.
The wattage density, which is referred to as Watt/in2 of the heating surface, is an important consideration in the design of heating systems. Wattage does not describe the overall power of the system, but the extent to which the power is concentrated on the surface of the heater. For example, a 1000 watt system with a heater with a surface area of 100 in2 has a wattage of 10 watts / in2. A 1000 watt system with a heater with a surface of 50 inches2 has a wattage of 20 watts / 2 inches. Both systems have the same power, but their wattage densities are very different. This is particularly important with regard to material compatibility.
The use of mica is inexpensive, allows to reduce the weight of the heater to a minimum, and accelerates the transfer of heat through the heating envelope and to and from the object that needs heat. Mica belt heaters work efficiently when jacket temperatures are kept below 250°C. If this temperature is maintained, the service life of belt heaters is extended.
Enthalpy is defined as the amount of heat required to change the temperature of the mass unit of the material from one temperature to another. Therefore, the amount of heat required to change the temperature of a material between the specified limits is the product of its mass and the change in enthalpy. Depending on the tool, the injection molding machine may not need to operate at full clamping pressure.