The results of investigations of plasticity of moulding sands with binders obtained by measuring deflection angles in the single point bend test in dependence on their hardening degree are presented in the hereby paper. Shaped samples made of moulding sands obtained in the technology with urea-furfuryl resin Furanol FR75A and in the technology with water glass, were subjected to various tests. Shaped samples were made on the quartz matrix of a medium grains size 𝑑𝑙=0,29 𝑚𝑚. Investigations were performed for the resin content being 1% and 2%, at a constant proportion of a hardener versus resin - equal 60%. In the case of sands from the technology with water glass, investigations were performed for 3.5% of water glass versus sand matrix and 0.35% of Flodur. Plasticity tests were carried out with using the strength machine with a continuous recording of a sample deflection value. Measurements of deflection angles values in the bend test were performed on a series of simultaneously made samples at constant time intervals from the moment of their making. To determine the sand hardening degree the ultrasound technique was applied, according to the previously developed methodology [1]. Every time from the obtained results the characteristic of the growing stress as a function of deflection was prepared (𝜎). In addition, for the tested group of moulding sands, empirical relationships between the maximum deflection angle (αmax) in the bend test and the hardening degree were determined (Sx): α = f(Sx).
W artykule zaprezentowano wyniki badań reologicznych powłok ochronnych: wodnej i alkoholowej, o trzech lepkościach umownych 10, 20 i 30 sekund. Badania lepkości dynamicznej prowadzono na lepkościomierzu rotacyjnym Rheotest 2. W wyniku przeprowadzonych pomiarów uzyskano krzywe płynięcia i wyznaczono zależność szybkości ścinania do lepkości dynamicznej, co pozwoliło sklasyfikować badane powłoki pod względem reologicznym.
EN
The article presents the results of measurements of rheological testing of protective coatings: water and alcohol, for three contracts viscosities 10, 20 and 30 seconds. Research of dynamic viscosity were performed on a rotary viscometer Rheotest 2. As a result of measurements of the flow curves were tested and determined the dependence of shear rate viscosity, allowing to classify the rheological properties of coatings.
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