Band Heaters: Mica- & Ceramic-Insulation
More Information
Band Heaters are primarily used on injection moulding and extrusion machines in the plastic industry. Other applications include packaging machines and general heating of containers, pipes.
A distinctive feature of these elements is even heat distribution over a large surface area.
Construction consists of heating wire, insulated with either mica-plates or ceramic formers. The elements are usually metal shrouded for mechanical strength.
Our band heaters are engineered to order, custom-manufactured in Cape Town & distributed across Sub-Saharan Africa.
contact us to discuss your requirements.
Mounting, storage & commissioning
Mounting
Good thermal contact between the element and metal surface to be heated is essential. Warping of elements will result in air pockets, causing hot spots and possible failure of the element. It is therefore important that elements are clamped on tightly and that clamps are retightened once elements have reached operating temperature.
Storage and Commissioning
Elements are susceptible to moisture and should be stored or used in a dry environment. It is recommended that elements are heated up gently after a prolonged period out of commission. This allows moisture to escape and prevents damage to the elements. Some temperature controllers have a "soft start" feature, but a similar result is achieved by turning the temperature controller down initially.
Fitting
Fitting of bands is preferably done by sliding them on. Where it is not practical, bands have to be bent open and then wrapped around the barrel. This causes deformation of the shape and possible damage. In this case it is advisable to use a "flexible band" (less rigid construction) or a hinged element.
Hinged elements are to be used where elements are removed frequently or where the diameter of the band is less than 150mm.
For elements with a diameter larger than 300mm, we recommend the use of spring loaded clamps to counteract the expansion during heating.
Mica & Ceramic Insulation
Mica Band Heaters
Mica insulation offers thin construction (4mm), maximum Watts of 3.5 W/cm² and operation up to 380°C. For process temperatures in excess of 280°, ceramic insulation is preferred.
Ceramic Insulated Heater Bands
Ceramic elements are thicker in construction (12mm) but offer a Watts density of 5.5 W/cm² and operating temperature up to 600°C. Generally ceramic elements are more durable than mica elements, thus offsetting the higher price with a longer life expectancy.
Calculation of maximum Power Rating
Band Heaters (Mica): P max (Watts)
= Width (mm) x Diameter (mm) x (3.14 x 0.035)
Band Heaters (Ceramic): P max (Watts)
= Width (mm) x Diameter (mm) x (3.14 x 0.055)
12 months warranty
Our warranty for custom-manufactured heater bands extends over a 12 months period from date of purchase and covers failure due to defective material or workmanship.
