Direct tensile tests on particulate agglomerates for the determination of tensile strength and interparticle bond forces

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Japan, 2017-09, Vol.28 (9), p.2177-2185
• Main Authors: Wollborn, Tobias, Schwed, Marcelo F., Fritsching, Udo
• Format: Article
• Language: English
• Subjects: Bond force; Capillary bonds; Particulate agglomerate; Tensile strength; Tensile test
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2017.05.024

[Display omitted] •Tensile tests on particulate agglomerates are compared to compression tests.•Ratio between tensile and compressive strength depends on adjusted parameters.•Rumpf’s model is used to calculate single bond forces from tensile test results.•Tensile simulation shows limitation of Rumpf’s model for solid bonded agglomerates. The importance of direct tensile tests on solid and capillary bonded particulate agglomerates is investigated and compared to compression test measurements. The properties of wet agglomerates are varied by changing the contact angle by means of functionalization of the particle surface. Process conditions are considered by variation of ambient humidity. A qualitative evaluation of the results is performed by analyzing the measured force distance curves of different tensile tests. The results are quantitatively evaluated by calculating the breakage strength, mass related breakage energy and breakage probability showing that the ratio between tensile and compressive tests is highly dependent on the adjusted parameters. Next to the process parameter effect, also the influence of agglomerate size is considered. Tensile strength data are used to estimate the single bond forces between the primary particles of the agglomerates. Tensile and compressive test results are compared to numerical results (DEM) of agglomerate breakage using an elastic stiff bond model.