Coil and cable heaters - Import export

Owing to their small cross-sectional dimensions, MicroCoils are most often connected at both ends and do not permit the addition of a thermocouple. We prefer to use nickel as the sheath material here because it combines the best thermal conduction properties, high corrosion resistance and excellent deformation properties. To ensure that the standard 1000 mm PTFE-insulated connection cable can be positioned at one end, despite the standard two-ended connection of the element, in most cases the MicroCoil is formed into a hairpin shape and wound/laid in a bifilar (parallel) format. Our unformed MicroCoils are also supplied in the hairpin bend shape as standard.

In linguistic usage occasionally the terms coil heaters, nozzle heating elements, hot runner heating elements, cable nozzle heaters are used. Our HotMicroCoil heating elements can be used in a wide variety of applications. Their high level of plasticity ideally suits them to the heating of hot runner nozzles and for accurately heating the contours of three-dimensional surfaces. Many of our customers order HotMicroCoil elements in their unformed state of mineral insualted cable heaters and perform the subsequent shaping work themselves, while others commission us to shape and fit the heating cable elements. A large number of ready-to-fit heating solutions are available for plastic injection nozzles with clamping mechanisms, housing bezel, reflection tube or heat conduction sleeve.

HotCoils have a larger cross-sectional area and are thus capable of greater power than MicroCoils. For this reason they are used in hot runners with adequate space and where high heat densities are required. Owing to the large number of variants and for cost reasons, the sheath material for HotCoils is stainless steel - the standard for the market and thus also for Freek. HotCoils are large enough that thermocouples can be integrated into them. Our standard here is Type J (Fe-CuNi; red/blue), while Types J and K are also available conforming to the IEC and ANSI standards (see colour codes). Since the measurement point of a built-in temperature sensor is situated in the heater and never where the heat is actually required, a HotCoil with a thermocouple makes particular sense where the application allows the use of larger processing (temperature) windows or where the installation location or the design requires protection against overheating.

Characteristics of our HotMicroCoils with reflection tube are easy mounting and variable heat distribution. Because of its direct touch and toleranced fit, the sleeve coil heater allows a very good heat transmission to the nozzle. In all our HotMicroCoil heaters with reflection sleeve the assembly of a thermocouple is possible and recommended for bigger diameters and power.

Cable Type Heaters have initially been developed and used for the safe operation in fertilizer plants. However nowadays, they cover a large range of applications due to their modular construction and minimum space requirements. They are suitable for heating up nearly all gases and liquids or superheating steam. They are mainly used in hazardous areas. Especially when processes require a combination of high power (in the MW range) high pressure and temperatures of up to 550°C cable type heaters are the means to choose.

Especially for high-cavity PET plastic injection moulding there are various industry standards of clamp-band nozzle heaters available. Most common are the Axial Clamp-Band Heater and the Two-screw Clamp-Band Heater. Our HotCoil cable heaters with clamp band represent a highly demanded and very flexible clamping system, especially for heating larger nozzles and bushings with high power. The size-variable customizable clamp bands counteract the heating's thermal-related "lifting ambition" during heat-up and thus effectively prevent a possible critical overheating. For an even better protection all HotCoil heating elements can also be provided with an integrated thermocouple. As alternative to our standard clamping mechanism with welded clamping elements a space-saving lug clamping mechanism can be supplied.