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This paper aims to determine how the viscosity and curing agent content affect the flowability of moist silica sand granules. In addition, a coating device was designed according to the flow properties of silica sand granules.

The flowability of silica sand granules premixed with two curing agents of different viscosities is studied using a Jenike shear apparatus. An open-ended device was used in discharge testing of sand granules with a design based on the variable dip angle of the two plates and variable outlet size.

The test results show that increasing the curing agent content would significantly decrease the flowability of silica sand granules, and a curing agent of higher viscosity has a greater effect on the flowability of silica sand. The presence of a curing agent strengthens the cohesion among sand granules, lubricates them and restrains their deformation. The shape function of the coating device was obtained by theoretical derivation.

The flow properties provide a valuable theoretical guidance for the design of coating device for sand mold printing.

This paper deals with experimental work on flow properties of silica sand granules with different viscosities and curing agent content. The shape function of a wedge-shaped coating device is obtained based on experimental data.

In microfluidic channel fabrication in low temperature co‐fired ceramics (LTCC), one of the biggest challenges is the elimination of channel deformation during lamination. The purpose of this paper is to describe the expected deformation of the substrate and the sacrificial layer (starch powder and 3D printed UV polymerized material) during the lamination process of microfluidic structure fabrication.

Uniaxial compression and Jenike shear test were used to obtain the mechanical parameters of starch sacrificial volume material (SVM). To determine the stress‐strain characteristics of LTCC a uniaxial compression experiment was conducted. The shape of the laminated LTCC containing embedded channel was modeled by finite element method using the mechanical parameters obtained by the measurements.

It was found that the choice of SVM plays an important role in channel deformation. A design rule is given considering the channel width and the choice of SVM based on the simulation results.

Until now the lamination step of LTCC technology was only optimized in an empirical way.

The purpose of this study is to analyse the problem of high binder content in sand mould and to solve it. Meanwhile, to increase build speed, especially for heavy casting’s sand mould with a high value in layer height, such as 2 mm in construction instead of the industry standard of 0.3 mm, line forming for three-dimensional (3D) sand mould printing is researched.

Brief introduction of 3D sand mould printing and key issues are given first. Then, this paper quantitatively analyses binder content in sand mould. Finally, to acquire sand mould with appropriate binder content and high build speed, line forming combining traditional furan no-bake sand manufacture technique is researched, as well as relevant feasible schemes and current progress.

The study shows that compared with traditional technique, binder content in sand mould produced by available 3D printing technique is too high, bad for sand mould’s properties and quality of castings, while line forming brings guaranteed binder content and improved build speed.

More experiments are needed to demonstrate quantitative analysis of binder content and to obtain flowability of moist sand, detailed structure design of nozzle and practical build speed, as well as methods of circulation of materials considering solidification time.

Line forming with higher build speed and suitable binder content means excellent properties of sand mould and castings as well, bringing obvious implication for moulds industries and manufacturing industry.

This new method could increase build speed and meanwhile guarantee binder content. Thus, its application prospect is promising.

The purpose of this study is the reduction of computational time demand of discrete element based modeling.

The methodology is the systematic changing of particle size and micromechanical parameters to reduce computational time requirements.

In some cases, the computational demand of discrete simulations can be reduced to about 95 per cent.

Based on the results and demonstrated methodology, the enormous computational time demand of discrete element-based modeling can be reduced significantly.

Burden transport is a ubiquitous primate behavior. Modern humans, however, take this primate tendency and extend it to a behavioral repertoire that influences many of our daily activities and almost certainly helped shape our physical and behavioral form. I examine the transportation of food in the context of central place foraging, from the perspective of maximizing energy acquisition. A detailed model of the energetic cost of burden transport is presented and its sensitivity to the variables of body mass, burden mass, terrain, incline and velocity discussed.

The analysis of the effect of tool vibrations on the measured and simulated draught forces of cultivator tools. This paper aims to discuss this issue.

Soil bin measurements and discrete element method (DEM)-based simulations.

The soil-tool interaction induced free vibrations of cultivator tools have significant impact on the measured draught force, and the simulations made by using vibrating tools give similar results.

Accurate calibration of discrete element model parameters can be done based on the reproduction of the whole Mohr-Coulomb failure line. Draught force ratio – velocity ratio values seem to be independent of tool geometry and soil conditions in case of velocity ratio higher than 2.

DEM-based numerical simulations can be used for modeling the effect of tool vibration on the draught force values. During discrete element simulations of soil-tool interaction, the effect of tool vibration may not be neglected.

The paper demonstrates that during the discrete element modelling of the soil-tool interaction, the tool vibration phenomenon should not be neglected.

Transportation of the measurement samples from their original place to the measurement site causes significant changes in their mechanical properties. The possibility of making in situ measurements helps to create more precise discrete element models.

The possibility of using in situ modified vane shear test based measurement for the calibration of discrete element models is demonstrated in this work.

The advantage of employing the adjusted vane test is that the values of in situ measurements can be used for the calibration.

The procedure we present allows us to perform accurate discrete element calibration using data from on-site measurements that can be performed quickly and easily.

The purpose of this paper is to demonstrate the processability of cohesive PE-HD particles in laser beam melting processes (LBM) of polymers. Furthermore, we present a characterization method for polymer particles, which can predict the quality of the powder deposition via LBM processes.

This study focuses on the application of dry particle coating processes to increase flowability and bulk density of PE-HD particles. Both has been measured and afterwards validated via powder deposition of PE-HD particles in a LBM machine.

For efficient coating in a dry particle coating process, the PE-HD particles and the attached nanoparticles need to show similar surface chemistry, i.e. both need to behave either hydrophobic or hydrophilic. It is demonstrated that dry particle coating is appropriate to enhance flowability and bulk density of PE-HD particles and hence considerably improves LBM processes and the resulting product quality.

At present, in LBM processes mainly polyamide (PA), 12 particles are used, which are so far quite expensive in comparison to, for example, PE-HD particles. This work provides a unique and versatile method for nanoparticulate surface modification which may be applied to a wide variety of materials. After the coating, the particles are applicable for the LBM process. Our results provide a correlation between flowability and bulk density and the resulting product quality.

The purpose of this paper is to investigate the effect of different heating approaches during thermal rounding of polymer powders on powder bulk properties such as particle size, shape and flowability, as well as on the yield of process.

This study focuses on the rounding of commercial high-density polyethylene polymer particles in two different downer reactor designs using heated walls (indirect heating) and preheated carrier gas (direct heating). Powder bulk properties of the product obtained from both designs are characterized and compared.

Particle rounding with direct heating leads to a considerable increase in process yield and a reduction in powder agglomeration compared to the design with indirect heating. This subsequently leads to higher powder flowability. In terms of shape, indirect heating yields not only particles with higher sphericity but also entails substantial agglomeration of the rounded particles.

Shape modification via thermal rounding is the decisive step for the success of a top-down process chain for selective laser sintering powders with excellent flowability, starting with polymer particles from comminution. This report provides new information on the influence of the heating mode (direct/indirect) on the performance of the rounding process and particle properties.