Tips

When considering heated roller design and capabilities it is important to understand the wattage requirement for the application. The wattage required to heat the roller in an acceptable amount of time for your application is an important consideration. However, of equal or greater importance is the wattage required to heat your web and maintain roller temperature while your web is pulling away calories.

Wattage requirement for getting the heated roller to temperature and heating your web while maintaining roller temperature can be calculated for any application. This information is crucial to accurately calculate wattage and ultimately design the heated roller, properly, for your application:

• What types of materials will you process with the heated roller? This information helps to give us an overall understanding of the scope of your project.
• How fast do you want to heat the roller to your required temperature?
• What is the density of the web material you will heat with the roller? This should be expressed as Lbs./in³
• What is the thickness range (thinnest to thickest) of your web?
• What is the temperature rise for the roller? This will be ambient temperature (roller not energized) subtracted from maximum temperature required. So, for example, if your ambient temperature is 70^oF and you want to heat the roller (and your web) to 120^oF, then your temperature rise (120-70) = 50^oF.
• What is the running speed (minimum to maximum) of your machine?
• What is the web wrap around the circumference of the roller? This is expressed in degrees.
• Is there a desired heated roller diameter or restrictions for diameter?
• What is the width range (narrowest to widest) of your web?
• What is the specific heat of your web material? This should be expressed as BTU/(Lb.)(^oF). This is, perhaps, the one of the hardest specifications to attain. However the wattage requirement is directly affected by this value. For example, the specific heat of copper foil will be vastly different from paper, therefore, wattage requirement for a heated roller designed to heat copper foil will be vastly different from a heated roller designed to heat paper. The good news is a quick web search for the specific heat of your web material will often times glean good results.

A properly designed heated roller will heat web to desired temperature and maintain that temperature through the full scope of the machines capabilities. To ensure a proper design, keep the information listed above on hand.