Electricity and Control July 2020

MEASUREMENT + INSTRUMENTATION : PRODUCTS + SERVICES

Accurate temperature profiling in paint curing

In the process of paint curing, as used in the automotive industry, for example, where the quality of the paint finish is critical, oven temperature profiling is the only truly ac- curate method by which the process can be monitored to determine that the paint cure schedule has been correct- ly achieved. This is according to Gerhard Otto of R&C Instrumentation. Otto explains that the oven temperature profiling system is designed in such a way that it is able to travel with the car body through the cure oven, continuously measuring the product temperature at selected locations on the car body. At the end of the process, the collected temperature readings create a thermal profile of the product from which the cure schedule can be measured and validated. An oven profiling system consists of four elements: - Thermocouples which are attached to the product to measure actual product temperature - A data logger that captures and stores the tempera- ture data from the thermocouple - A thermal barrier, an insulated box which protects the data logger from the hostile conditions within the oven - A software package which provides the user with tools to review, analyse and generate reports on the temperature profile. As a leading manufacturer and service provider for temperature profiling systems, Datapaq provides the industry’s most complete offering for monitoring, logging, and profiling of temperatures in applications involving furnaces, ovens or dryers. In any production environment, time is of the es- sence. Prior to the run, using the feature called Smart- Paq, the user can program the logger with target per- formance criteria (maximum temperature limit, time at temperature target, or acceptable Datapaq value

range). The data collected by the data logger is ana- lysed against these criteria at the end of the run and the logger displays whether the criteria have been met or not. The SmartPaq feature makes profile qualification as easy as checking for a ‘green pass’ LED, which means the user can move on to the next oven with confidence and without any need to download data. The data can be analysed in full later after all runs are completed. If the LED is red, the user immediately knows at the oven exit that there is a process problem. Knowing this as soon as possible is critical to reducing rework, since the root cause of the problem can be identified much earlier in the process. The MicroMag is a probe designed by Datapaq spe- cifically to meet the demands of general automotive paint profiling strategies. The compact sensor can be placed in the tightest of recesses, allowing those difficult areas to be measured accurately and efficiently. The high per- formance, encapsulated samarium cobalt magnet guar- antees secure fixing of the temperature probe. An important requirement of the thermal barrier is the absence of silicone. To avoid unacceptable paint con- tamination issues such as paint craters, the Datapaq barrier is designed to use insulation material that does not contain silicone or any silicone derivatives. The Datapaq Insight software can perform an automatic temperature difference analysis to highlight problem areas within the process. Such data is important to allow identification of the root cause and necessary corrective action. Data reporting and archiving is critical to the certification of automotive processes, whether users are working with ISO 9000, QS 9000 or CQI‑12. The Insight system has been developed to allow customisation of the full report generated to include the specific data

and information required. Within the Insight software, the SPC program automatically produces SPC charts without any need for data export or use of an external software package. Johannesburg-based R&C Instrumentation supplies the Datapaq range of temperature profiling systems.

For more information, contact R&C Instrumentation. Tel: +27 (0)11 608 1551 mobile: +27 (0)71 471 2056 email: info@randci.co.za or visit: www.randci.co.za

Accurate temperature profiling in the paint curing process is critical in the automotive industry where the paint finish on vehicles must be without defect.

20 Electricity + Control JULY 2020