We are strongly supported by a well established and fully equipped R&D unit, helping us to manufacture and supply a wide range of High Watt Density Cartridge Heaters. These heaters are highly used in food processing machinery, packaging machinery and hot stamping applications. To comply with the set industrial norms, we use finest quality materials and components, sourced from the most authentic vendors to manufacture the heaters. We precisely check the High Watt Density Cartridge Heaters on certain quality parameters before offering to clients at the affordable prices.
Introduction to Cartridge Heaters
What is a Cartridge Heater?
A cartridge heater is a device that is usually tubular and is inserted into drilled holes of metal blocks for heating.
Cartridge Heater Selection
The key questions which need to be answered before selecting a cartridge heater are:
Application Of Cartridge Heaters
The majority of applications do not require maximum watt/in. Use a watt density only as high as needed. Take advantage of the safety margin provided by using ratings less than the maximum allowed. Select space heaters for most even heat pattern rather than the highest possible wattage per heater.
Hi-Density Cartridge Heaters
Hi-Density Heaters provide localized heating in processes requiring close temperature control such as:
Hi-Density Cartridge Heaters Metric Diameters ,Standard Sizes and Ratings by Diameter
6.5mm, 8 mm,10 mm, 11.5mm,11.8mm,12.5 mm, 16 mm, 18.5 mm, 19.5 mm, 20 mm, Other Sizes can be also made as per specifications
Temperature Controllers and Sensors for
The sensor for the temperature control is also an important factor and should be placed between the working surface of the part and the heaters. The temperature of the part approximately 1/2" away from the heaters is used in selecting maximum allowable Watt density from the graph.
Control of power is an important consideration in high Watt density applications. On-off control is frequently utilized, but it can cause wide excursions in the temperature of the heater and working parts. Thyristor power controls are valuable in extending the life of high Watt density heaters, since they effectively eliminate on-off cycling.
There are a variety of temperature controllers and sensors one can use depending on the application. One of the more popular sensor types for cartridge heater applications are the surface mount temperature sensors. Thermocouple, RTD or Thermistors are available with an adhesive backing or the ability to be cemented to the surface being heated. There also bolt on and magnetic surface mount type temperature sensors available. Digital temperature controllers come in many different sizes with many output and input choices. Thermocouple and RTD inputs are the most popular with a dc pulse output. DC pulse outputs allow the user to go to a larger relay to switch the heater load and use proportional control versus on/off control which can shorten the heater life.
Important Installation Considerations
Note: To protect the heater from damage in these harsh environments, Dydac has a wide selection of terminations and options available.
Recommendations for Improving the life of Dydac High Watt Density Cartridge Heaters
Dydac Hi-Density Cartridge Heaters have been widely used in many demanding and diverse applications during the past quarter century. The most common applications are platen, plastic mold and die heating, liquid immersion and air heating. Selection of the wrong termination for the particular application is the major reason for all heater failures. However, failure to consider other important criteria can also have a negative effect on the life of the heater. To get the best performance and assure long life, it is important to carefully evaluate the following factors.
Heater Watt Density and Operating Temperature
Cartridge heater watt density is defined as the wattage dissipated per square inch of the heated sheath surface. For a particular application a heater's watt density governs internal resistance wire temperature, which determines the outer sheath temperature. It is advisable to use heaters that have watt densities below the maximum recommended watt density for the material being heated to achieve the longest heater life. A Hi-Density cartridge heater designed at the maximum recommended watt density allows the smallest heater to be used to obtain the required wattage with good service life. All things being equal, using a lower watt density heater will typically provide optimized service life.
When heating a platen, mold, die or hot runner probe with Hi-Density Cartridge Heaters inserted into drilled holes, fit is an important factor in determining the life expectancy of the heater.
Temperature Control and Location of Temperature Sensing Device
In order to better control the heater temperature and hence the resistance wire temperature, use of an appropriate temperature control and the proximity of the heater to the sensor is very important. Higher watt density heaters can generate heat faster than the surrounding area's ability to dissipate heat. This creates a thermal lag between the heater and the sensor. The closer the sensor to the heater, the better you can control the heater temperature. By keeping the sensor further from the heater, temperature gradients of several hundred degrees can be observed in many applications, especially during initial start-up and heavy thermal cycling. Although the set operating temperature may be low, the heater may be running at a very high temperature. This is a common cause of heater failure. This can be minimized using time proportional and PID functions of the temperature Controllers.
Temperature Control and Location of Temperature Sensing Device
In order to better control the heater temperature and hence the resistance wire temperature, use of an
Power control methods affect the life expectancy of heating elements. In general, although economical, on-off controls increase thermal fatigue and oxidation rate on heating elements by causing wide temperature swings of the internal heating element. Silicone controlled rectifiers (SCR's), and solid state power controls can increase the life expectancy of heating elements by reducing the temperature swings of the internal heating element