CPC B29C 66/91421 (2013.01) [B29C 65/20 (2013.01); B65D 88/1681 (2013.01); B65D 88/54 (2013.01); G01K 7/02 (2013.01); G01K 15/005 (2013.01); B29L 2031/7128 (2013.01)] | 20 Claims |
1. A system for temperature sensing and control of a heating element of a heat seal bar, the system comprising:
a) a control panel that includes a controller, a transducer, a transformer and a switching device;
b) a heat seal bar including a heating element;
c) a sensor that is in contact with the heating element of the heat seal bar prior to using the heat seal bar in a heat seal cycle and removable from the heat seal bar during heating in the heat seal cycle;
d) wherein the controller is operable to provide calibration values of the heat seal bar during a calibration cycle based on temperature values received from the sensor and electrical resistance values of the heating element;
e) wherein the transformer is operable to apply power to the heating element after the calibration cycle when the sensor is removed from the heating element;
f) wherein the transducer is operable to process voltage and current feedback signals received from the heat seal bar, which the controller uses to calculate real-time electrical resistance of the heating element during the heat seal cycle; and
g) wherein the controller calculates temperature of the heating element during heating based on the real-time electrical resistance of the heating element in step (f) and calibration data acquired by the controller.
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