Construction-Mica Insulated Band Heaters
Mica Insulated Band Heaters Metric-Construction
Mica Band Heaters are constructed by winding a nickel-chrome resistance ribbon around mica insulation and encapsulated in a stainless steel sheath. It is then formed to the desired diameter for installation over a dies, barrels and nozzles. They are available in an extensive variety of sizes and shapes with options for holes, notches and cut-outs. A number of threaded terminals, wire lead options and terminal boxes offer great flexibility for field wiring. With temperature capabilities of up to
900°F, these heaters are ideal for plastic processing applications and for anywhere heat is needed on a round or curved surface.
Highest grade mica insulation provides excellent electrical isolation at high temperatures and is resitant to moisture. Mica heaters made by NPH utilize different types of top grade mica. The thickness of each mica layer is carefully selected in order to balance between the insulating characteristics of mica and the ease of heat transfer from the heating core to the machine barrel.
Nickel/Chromium restance wire evenly wound for uniform heat distribution and reliable accuracy. The resistance wire ribbon used in a NPH mica heaters is not restricted to the capabilities of nickel/chromium referred to as nichrome wire. Different alloys are considered for different applications. The internal winding is carefully designed to ensure uniform heat distribution throughout the band heater.The gauge of nickel-chrome resistance ribbon wire is selected to achieve the lowest internal element temperatures possible, resulting in maximum heater life. To maximize the surface-to-surface contact, our mica heaters are carefully rounded and formed to optimize the grip on a machine barrel.
The external metallic protective sheath of NPH band heaters is made of a special alloy, which expands less than the barrel when heated. This difference in thermal expansion makes the heater grip the barrel firmly once it is energized. This improves heat transfer which extends the life of the mica band heater.
General purpose terminal box can be attached on NPH heater diameters of 2-1/2" or larger. It offers excellent protection to
exposed terminals. To simplify wiring, the box has a 1/2" trade size knockout (actual diameter 7/8") that will accept standard conduit or flexible armor cable connectors. It can be field assembled on most band heaters with screw terminals having a center distance of 7/8". Sandard 12" fiberglass leads are UL and CSA rated and provide protection up to 850° F.