A thick film resistive heating element having a thick film resistive track applied to the surface of an electrically insulative substrate. An encapsulating insulating layer is applied over the track to protect it while an area of the element is left uncovered by the encapsulating layer so as to define a window. A portion of a temperature sensitive control device is then placed in direct contact with the track and/or the electrically insulative substrate through the window. The window in the element is located in that area of the element which will be uncovered by the liquid prior to the rest of the element as the liquid boils away or is evacatuated from the vessel.
An injection molding system and injection molding method for making molded parts that include one or more planar heaters having a thin or a thick film resistive heater element coupled, secured, or releaseably secured to one or more sides of each of the one or more injection molding nozzles. The releasably secure coupling allows heater device to be visually inspected, tested, removed, and/or replaced. The planar heater device can have a support device patterned with a film electrical resistive path. The electrical resistive path can include any pitch or number of electrical resistance lines, such that a longitudinal uniform heat profile is generated along a melt flow channel of the one or more injection molding nozzles when the nozzles are in use. In some examples, the planar heater has more than one film resistive heater element that can be coupled to one or each side of a nozzle, with dielectric material interposed between the planar film resistive heater elements. This can allow for additional or alternative heating in various applications.
A system and method for making molded parts that include one or more planar heaters coupled, secured, or releaseably secured to one or more sides of each of the one or more nozzles. The releasably secure coupling allows heater device to be visually inspected, tested, removed, and/or replaced. The planar heater device can have a support device patterned with an electrical resistive path. The electrical resistive path can include any pitch or number of electrical resistance lines, such that a longitudinal uniform heat profile is generated along a melt flow channel of the one or more nozzles when the nozzles are in use.
A heater system is provided with a layered heater in communication with a two-wire controller, wherein a resistive layer of the layered heater is both a heater element and a temperature sensor. The two-wire controller thus determines temperature of the layered heater using the resistance of the resistive layer and controls heater temperature through a power source. Furthermore, a heater system using a layered heater in communication with a two-wire controller for a specific application of a hot runner nozzle in an injection molding system is provided by the present invention.
A hot runner nozzle heater system is provided with a layered heater in communication with a two-wire controller, wherein a resistive layer of the layered heater is both a heater element and a temperature sensor. The two-wire controller thus determines temperature of the layered heater using the resistance of the resistive layer and controls heater temperature through a power source.
