Drying of water based foundry coatings: Innovative test, process design and optimization methods

This work has been carried out in in partial fulfilment of the requirements for the award of the degree of Doctor of Philosophy (PhD) at the Technical University of Denmark. Associate Professor Niels Skat Tiedje has been the university supervisor from March 2012 to February 2015. Casting Technology Director Bjørn Budolph Johansen has been the company supervisor from March 2012 to June 2014.

In this Industrial PhD Thesis we present the main results of several tests and simulations carried out from 2011 to 2014 at Global Castings A/S (former Vestas Wind Systems A/S) and at the Technical University of Denmark with the overall aim to optimize the drying process of water based foundry coatings.

Drying of foundry coatings is a relatively new process in the foundry industry that followed the introduction of water as a solvent. In order to avoid moisture related quality problems and reach production capacity goals there is a need to understand how to design, control and optimize drying processes.

The main focus of this project was on the critical parameters and properties to be controlled in production in order to achieve a stable and predictable drying process. We propose for each of these parameters simple methods for testing both at laboratory and production scale so that material characterization and model validation can be carried out also for materials different from the ones considered in this study.

Additionally, we present the application of calculation methods and advanced simulation tools on real industrial cases. These tools have been developed in order to simulate and optimize the drying process and reduce drying time and power consumption as well as production process design time and cost of expensive drying equipment.

Results show that test methods from other industries can be used or adapted to better control drying processes of water based foundry coatings. Critical drying process related properties were obtained in the several laboratory tests performed and calculation and simulation methods were developed. Additionally, examples of improvement on full scale industrial production line are shown.