Optimierung der Pulverlackapplikation durch Anwendung experimenteller und numerischer Untersuchungsverfahren

In the course of an increasing employment of powder coating technology, the complex interrelations in the powder application, mainly the particle size distribution and its influence, must be understood. For that, in the first part a new measuring method had to be developed, to make visible the problematics and in the next part to find a solution for it. This includes: the monitoring of the process control parameters (powder mass flow rate, particle size distribution, electrostatics, air flow and climate), the development of a new testing method for powder spray systems, the development of a simulation method to predict the recycling behaviour (KAP-SIM-method), the employment of a newly developed charge spectrometer for coating powder. With the aim of these methods in the experimental optimization measures the following process parameters were taken into consideration: particle size spectrum of coating powder, coating powder recovery method and the distribution nozzles of the spray systems. For an increasing and efficient use of powder coating systems in the future, the users demand more flexible powder spray guns. That means powder guns with which the dimensions of the spray cloud may be shaped continuously. The present thesis was aimed at realizing such powder spray systems in form of powder spray guns using aerodynamical and electrostatical solution approaches. Two completely different solutions were separately realized. On the field of electrostatics mainly the influence of steering electrodes was tested. In combination with tribo charging powder this electrodes are very effective. On the other hand, a new pistol could be dimensioned and optimized with the help of numerical simulation. The continuous regulation of the spray cloud was realized with additional controlling airs. In the future, the simulation will be an important tool in the investigation of complex powder coating processes. In the development of such systems the simulation will be used more and more. With it, the development time of the product is reduced. Therein the powder guns are only one part in the coating process. In the future, not only powder applicators will be simulated on the computer but also whole coating processes and coating lines