Hydro-abrasion wear of metering systems by conveying high-viscosity adhesives
In order to develop metering systems for processing highly viscous and highly filled adhesives with an adequate service life, it is necessary to estimate the abrasion caused by the filler in the adhesive to be processed at design stage. Within the scope of are search project  fast test, and simulation, methods were developed accordingly. The methods enable to estimate at an early stage the abrasion wear of higher viscous and filled adhesives with unknown composition on the metallic parts of dosing systems. Novel tribometers have been designed, constructed, and tested using sample adhesives with known fillers and commercial adhesives. The tests in  covered the following wear types: sliding wear, tamped wear and hydro-abrasive wear. The presentation focuses on hydro-abrasive wear. For this type of wear, a new mode land a new test-device was developed, and subsequently improved. The model describes the abrasive wear by adhesives in qualitative terms. The experiments carried out support the assumption that wall shear stress is decisive for material removal at the flow conducting components in the event of flow wear. Flow simulations, based upon Computational Fluid Dynamics (CFD), of adhesives  inside dosing components support the new wear model. The model was implemented in a flow simulation code to highlight areas of the metering components that are particularly prone to wear. Wear simulations were carried out on three different components of metering systems. The positions of the highlighted areas in the numerical simulations are in good agreement with the wear points of industrial dosing systems.