Abstract: An instrumented heater sleeve is provided that has a plurality of zones, a dielectric layer disposed over an outer surface of the sleeve, a resistive element layer disposed over the first dielectric layer, and a plurality of pairs of lead wires secured to a portion of the resistive element layer. Each pair of lead wires is connected to and corresponds with each of the zones and a protective layer is disposed over the dielectric layer. An amount of power is supplied to each of the zones and adjusted during a test run, or multiple test runs, to achieve a desired temperature profile along a heating target such as a hot runner nozzle. Methods of designing a hot runner nozzle heater using the instrumented heater sleeve are also provided.

Abstract: A heat trace assembly for heating a conduit is provided that comprises at least one preformed heat trace section adapted to be placed around at least a portion of the conduit and a connector secured to the heat trace section. The connector is adapted for coupling the heat trace section to an adjacent heat trace section, and the heat trace section and the connector have mating mechanical features to allow the heat trace section to be quickly connected to and disconnected from the conduit. Additionally, a heat trace junction is provided that preferably defines a cross configuration and comprises a plurality of arms extending from a central portion of the heat trace junction. The plurality of arms are deformable to conform to a junction within a conduit system. Thermal insulation jacket configurations are also provided in accordance with several embodiments of the present invention.

Abstract: An instrumented heater sleeve is provided that has a plurality of zones, a dielectric layer disposed over an outer surface of the sleeve, a resistive element layer disposed over the first dielectric layer, and a plurality of pairs of lead wires secured to a portion of the resistive element layer. Each pair of lead wires is connected to and corresponds with each of the zones and a protective layer is disposed over the dielectric layer. An amount of power is supplied to each of the zones and adjusted during a test run, or multiple test runs, to achieve a desired temperature profile along a heating target such as a hot runner nozzle. Methods of designing a hot runner nozzle heater using the instrumented heater sleeve are also provided.

Abstract: A hot runner nozzle heater is provided that includes a sleeve defining a slot extending along a length of the sleeve. A first dielectric layer is disposed over an outer surface of the sleeve, and a resistive element layer is disposed over the first dielectric layer, wherein the resistive element layer defines a resistive circuit pattern that is preferably formed by a laser trimming process. A pair of terminal leads are secured to a portion of the resistive element layer thus defining a termination area, and the termination area is positioned proximate the slot and away from the proximal end and the distal end of the sleeve. A second dielectric layer is disposed over the resistive element layer but not over the termination area, a third dielectric layer is disposed over the termination area, and a protective layer disposed over the second dielectric layer and the third dielectric layer.

Abstract: A method is shown of predicting failure of resistive element heaters using a compiled database of measured ratiometric factors affecting heater life. The method can either be carried out actively, by continuously measuring known factors affecting heater life and decrementing a count of the remaining heater life, or the method may be carried out passively by estimating the operating profile and the averages within each segment of the profile, of the factors affecting heater life.

Abstract: A method is shown of predicting failure of resistive element heaters using a compiled database of measured ratiometric factors affecting heater life. The method can either be carried out actively, by continuously measuring known factors affecting heater life and decrementing a count of the remaining heater life, or the method may be carried out passively by estimating the operating profile and the averages within each segment of the profile, of the factors affecting heater life.

Abstract: A method is shown of predicting failure of resistive element heaters using a compiled database of measured ratiometric factors affecting heater life. The method can either be carried out actively, by continuously measuring known factors affecting heater life and decrementing a count of the remaining heater life, or the method may be carried out passively by estimating the operating profile and the averages within each segment of the profile, of the factors affecting heater life.

Abstract: An electric, resistance element heater utilizes quartz as a sheath material and has a resistance (heating) element that is in intimate, substantially continuous contact with a surface of the quartz. This allows the heater to operate in any one or all of the three modes of heat transfer, namely, radiation, conduction and convection. Such intimate, substantially continuous contact of the resistance element is achieved by applying the element in direct contact with the quartz surface. This is accomplished by applying a heating circuit directly to the quartz surface, which heating element can be a foil element, or a thick or a thin film deposition element. The overall heater is formed by covering the heater element by a quartz sheath and attaching leads formed on the ends of the heater element to a source of electric energy. Sensors such as thermocouples, RTD's and the like can also be incorporated directly into the heater structure. Also, the heater can be fashioned into a variety of shapes.

Abstract: Hot runner injection molding systems with externally heated injection runner nozzles for such systems. The heater is preferably a tubular heater with the resistive element applied to the exterior surface by fine film printing. The heater is adapted to externally heat a hot runner injection mold runner nozzle.