Contactless temperature measurement

13 March 2023

Contact-free measuring of temperature with pinpoint accuracy, with thousands of measurements per second is helping improve quality control of a crown cork production line.

Around 22 billion crown corks are produced in Germany every year and quality is key, to ensure they do their job and keep carbonated fluids contained in their bottles.

The corks rely on a seal made of thermoplastic elastomer (TPE) which is molded into the inside of the crown cork in the form of a pellet together with glue varnish. The glue varnish is activated at around 150°C and the TPE pellet is pressed into shape. This process happens at a rate of 83 times per second, or just under 5,000 times per minute.

Temperature is crucial to the process because it activates the adhesive coating for the thermoplastic elastomer seal. But at this rapid speed, how do you know whether the temperature is correct for every cork? Non-contact temperature measurement provided by Optris sensors are used on the production line to monitor the temperature.

Originally, an optris sensor – with a response time of 1 ms  – was used on a trial basis. The temperature measurement with this system delivers around. 12 measured values per crown cork. After evaluating the temperature-time diagram, the need arose for an even more detailed recording of the temperature distribution as the crown cork passed by. For this reason, a change was made to a new Optris sensor which was able to offer higher temporal detail resolution due to it being a faster sensor.

The new sensor can operate with a response time of 90 microseconds. In this time, the sensor takes more than 1,600 measurements which enables temperature of each crown cork to be individually recorded as it passes through the production line. This ensures constant heating of the crown corks at full process speed, guaranteeing the quality of the sealing insert bonding. 
At the heart of the Optris sensor is a indium antimony arsenide detector which enables the combination of a low temperature measuring range, which already starts at 0 °C with a measuring speed of 90 µs. 

Contact Details and Archive...

Related Articles...

Print this page | E-mail this page