Thermal processing serves a broad range of industries and is fundamental to the performance, quality and safety of a wide range of products.
Processes vary from paint curing, soldering, and heat treatment of materials all the way to further processing of food and ceramics firing. One thing that all of these applications have in common is that there are established requirements that the end products must meet and in most cases these requirements are affected either directly or indirectly by the thermal processes the products go through.
Regulation and quality management are a key part of our industrial processing world. There is a clear drive to develop preventative rather than reactive quality and maintenance systems. This is being driven by higher end user expectation and increased regulation both from national standards and equipment manufacturers/ end user specifications. Examples of these created by AIAG for use in the automotive supply chain are CQI 9 for the heat treatment of metals, CQi12 for the application and curing of coatings and CQi17 for soldering of electronic assemblies. In the Aerospace industry AMS2750 BAC 5621 and RPS 953.
Meeting the requirements of these standards with traditional post process inspection data is difficult. If all heat treatment processes have been undertaken correctly and recipes adhered to yet a post process inspection is failed how can a proper root cause analysis and corrective action plan be implemented and verified? This problem highlights a growing need for through process data. This allows users to develop a better understanding of equipment condition and product response to thermal processing. With this information equipment maintenance can become preventative rather than reactive, product throughput can potentially be increased. All the additional information provide by having a complete thermal profile of the process can be used to develop continuous improvement plans, this is a key part of the transition from ISO 9001:2008 to ISO 9001:2015.
For example, in a food processing facility cooking poultry the inspection of a product at the end of the oven using a temperature probe is a commonly used way to comply with the HACCP Guidelines. The resulting measurement may indicate that the product is undercooked, this would result in the product being deemed not fit for consumption and therefore disposed of. If the recipe for the cook was adhered to the information available would make it difficult to deduce the cause of the failure and so the corrective action. Using a through-process data logger to monitor both the oven temperature and the temperature of the product throughout the entire process will ensure that locating the fault that caused the issue, perhaps a broken fan or burner/heating element much easier
As the regulatory requirements become more stringent and quality management system requirements drive toward a philosophy of continuous improvement it is clear that the data provided by through process profiling is invaluable. Demonstrating process control is simplified and real-world improvements in yield, process efficiency and product quality can be achieved.