Hot runner nozzle heater and methods of manufacture thereof
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.
1. An instrumented heater sleeve comprising:
a sleeve having a plurality of zones;
a first dielectric layer disposed over an outer surface of the sleeve;
a resistive element layer disposed over the first dielectric layer;
a plurality of pairs of lead wires secured to a portion of the resistive element layer, wherein each pair of lead wires is connected to and corresponds with each of the zones;
a second dielectric layer disposed over the resistive element layer; and
a protective layer disposed over the second dielectric layer,
wherein an amount of power supplied to each of the zones is adjusted during a test run, or multiple test runs, to achieve a desired temperature profile along a heating target.
2. The instrumented heater sleeve according to claim 1 , wherein each zone is approximately 0.25 in. (10mm) in width.
3. The instrumented heater sleeve according to claim 1 , wherein the sleeve comprises one selected from the group of a slot or a step-lap interface extending along a length of the sleeve.
4. The instrumented heater sleeve according to claim 1 further comprising a control interface.
5. The instrumented heater sleeve according to claim 1 , wherein the instrumented heater sleeve further comprises a strain relief secured to the sleeve and in which the lead wires are crimped.
6. The instrumented heater sleeve according to claim 1 , wherein the protective layer is a moisture barrier adapted to seal pores in the underlying layers.
7. The instrumented heater sleeve according to claim 1 , wherein the sleeve has a shape selected as one from the group of cylindrical, elliptical, and polygonal.
8. The instrumented heater sleeve according to claim 3 , wherein the slot defines a non-constant width along its extended length.
9. An instrumented heater sleeve comprising multiple zones, each zone comprising a pair of lead wires secured to a resistive element layer; the resistive element layer being disposed over a first dielectric layer; the pair of lead wires providing for the application of power to a corresponding one of the zones such that power can be independently supplied to each of the zones to achieve a desired temperature profile.
10. The instrumented heater sleeve according to claim 9 further comprising:
a sleeve upon which the first dielectric layer is disposed;
a second dielectric layer disposed over the resistive element layer; and a
protective layer disposed over the second dielectric layer.
11. The instrumented heater sleeve according to claim 9 , wherein each zone is approximately 0.25 in. (10mm) in width.
12. The instrumented heater sleeve according to claim 9 , wherein the instrumented heater sleeve comprises one selected from the group of a slot or a step-lap interface extending along a length of the instrumented heater sleeve.
13. The instrumented heater sleeve according to claim 9 further comprising a control interface.
14. The instrumented heater sleeve according to claim 10 , wherein the instrumented heater sleeve further comprises a strain relief secured to the sleeve and in which the lead wires are crimped.
15. The instrumented heater sleeve according to claim 10 , wherein the protective layer is a moisture barrier adapted to seal pores in the underlying layers.
16. The instrumented heater sleeve according to claim 10 , wherein the sleeve has a shape selected as one from the group of cylindrical, elliptical, and polygonal.