OVENS , SPRABOOTHS & PROCESS HEATING
Why measure oven temperature ?
To ensure a successful cure of a powder coating for a quality , long-lasting finish , it is critical to accurately measure the temperature / time profile of the cure oven , particularly when loaded with the components to be cured .
Oven temperature / time profile is influenced by the thermal loading of the oven , therefore it is not sufficient to just set the oven zone controllers to an appropriate temperature value and expect the temperature / time requirements to be met .
An unsatisfactory cure results in a significant reduction in the quality of the final coating in terms of gloss , colour and adhesion . Too high a temperature can burn the coating and too low a temperature , or insufficient time at the required temperature , can result in an incomplete cure .
How to accurately measure an oven temperature
An oven data logger makes taking measurements and capturing the information simple , providing valuable data about the entire coating cure process . An oven logger is a measurement logging device with several connections for thermocouples . It is placed in a box which protects it from the high temperatures involved as it passes through the oven with any components , recording the temperature profile through the oven .
Although commonly known as an ‘ oven logger ’, it is not the oven temperature that is the critical measurement , but the temperature of the component . Not all components are alike and there is rarely a uniform density . Therefore , if not adjusted to suit the component being coated , the oven temperature settings may lead to under cure , coating burn , poor adhesion , discolouration , loss of gloss and other visible defects .
By using magnetic or clamp type air and surface temperature probes , temperatures can be monitored both on and around the product and recorded by the data logger , providing valuable information about the time taken to heat the component to the cure temperature and how long this temperature was maintained .
Monitoring and making adjustments to the oven temperature ensures that the product is brought to and held at , the specified temperature to ensure consistent quality of cure and visual properties at all times .
The Elcometer 215 Oven Data Logger
The Elcometer 215 Oven Data Logger is an easy-to-use , battery powered temperature data recorder that uses up to six K-type thermocouple probes to monitor the cure process . Complete with an efficient thermal barrier kit , the oven data logger is protected from temperatures of up to 250 ° C for a period of 100 minutes .
The oven data logger allows the user to control the cure process for a wide range of products and applications , storing up to
260,000 readings , or eight production runs . The data-logging interval can be set by the user from eight readings per second to one reading per hour . The Elcometer 215 also features a menu driven LCD screen which can display individual channel temperatures .
Six different clamp or magnetic K-type thermocouple probes can be connected to the logger simultaneously for measuring surface or air temperatures , with strong , flexible and easy-to-clean , Teflon ® coated cables in a variety of lengths . The probes have a continuous maximum operating temperature of 250 ° C and their low mass and optimised shape eliminates influence on the temperature of the component .
It ’ s what you do with your data that counts
ElcoMaster ® is a free , easy-to-use data management software ideal for the management and assessment of temperature profile . ElcoMaster ® allows the user to create and store unique oven profile setups ; name each of the six channels ; set sampling rates , number of batch runs and start / stop triggers and transfer them to the oven data logger . When one or more runs have been recorded , the data can be downloaded to ElcoMaster ® via USB .
Using the industry accepted cure value calculation ; ElcoMaster ® also provides instant pass / fail information by comparing the production run temperature to the coating supplier ’ s cure requirements .
Different powder types can be created and stored in ElcoMaster ® by simply entering the cure schedule into the software , creating a custom ‘ paint ’. This can be downloaded into the logger , ready for batch logging .
72 OCTOBER 2020 twitter : @ surfaceworldmag