The paper presents a computational method that allows to predict the process of drainage of flax seeds with expanded perlite and biohumus for complex pre-sowing treatment with preliminary irradiation of seeds in the infrared range. From a methodological point of view, in the process of seed granulation, the efficiency depends on the adhesive bond arising in the process of rolling and dispersing. To solve this problem, the calculations of mathematical models of the process of granulation of seeds and the process of dispersion of perlite with biohumus on the surface of seeds were carried out in order to obtain a finished dragee with components of natural origin and improve the sowing qualities of treated seeds and the finished product. As a result of the developed models, analytical solutions of kinetic problems for the process of precipitation of particles of a draining mixture of perlite and biohumus on the surface of flax seeds are obtained. The described mathematical model allows to determine the technological parameters of the granulation process-particle size of the granulating mixture and granulation time, for the calculation of granulating components in the development of technological equipment for granulation. The approximation of the obtained data was made, which showed the prospects and effectiveness of the ongoing developments.

Today, new methods of manufacturing complex parts using three-dimensional printing are being introduced in engineering, including in the mechanical engineering of agricultural machinery. This technique is also used in the design of agricultural machinery at the stage of physical modeling of their structures to determine certain properties of the product as a whole and its individual parts (details) on the corresponding models. Physical modeling is used when it is difficult to perform full-scale tests of the product, as well as for economic reasons. The necessary conditions for physical modeling are the geometric and physical similarity of the model and kind. The presence of such proportionality allows us to recalculate the experimental results obtained for the model in kind by multiplying each of the determined values by a constant multiplier for all values of this dimension – the similarity coefficient. However, to study the physical characteristics of a product, it is necessary to take into account the mechanical properties of the material of its model. From various sources, you can find the main mechanical characteristics of plastic threads or samples made on a 3-D printer. Their values vary greatly depending on the model manufacturing technology. The paper presents the results of a study of the physical and mechanical properties of polylactide (PLA) and polyethylene tereflatate (PET-G), which are used in the manufacture of parts by three-dimensional printing. The specific strength of polymers was respectively: for PLA 65.6…12.2 kPa·m3/kg, for PET-G 36.7…95.4 kPa·m3/kg. Specific plasticity for PLA is equal to 60.,3 %· cm3/kg, for PET-G – 468.2 %· cm3/kg. The specific plasticity for PLA is 608.3 %· cm3/kg, for PET-G – 468.2 %· cm3/kg. Mechanical properties are investigated and the obtained mechanical characteristics must be taken into account when calculating and physically modeling plastic products for three-dimensional printing.

No abstract

Increasingly, parts of complex shapes are made using three-dimensional printing. This technique is also used in the design of equipment at the stage of physical modeling of their structures to determine certain properties of the product as a whole and its individual parts (details) on the corresponding models. The necessary conditions for physical modeling are the geometric and physical similarity of the model and kind. The presence of such proportionality makes it possible to recalculate the experimental results obtained for the model in kind by multiplying each of the determined values by a constant multiplier for all values of this dimension – the similarity coefficient. However, to study the physical characteristics of a product, it is necessary to take into account the mechanical properties of the material of its model. From various sources, you can find the main mechanical characteristics of plastic threads or samples made on a 3-D printer. Their values vary greatly depending on the manufacturing technology of models and are determined under conditions of static loading only, which is not enough to study the stress-strain state of parts that are affected by suddenly applied, long-term and dynamic loads during machine operation. This paper presents the results of a study of the physical and mechanical properties of polylactide (PLA) and polyethylene tereflatate (PET-G), which are used in the manufacture of parts by three-dimensional printing. The specific stiffness of polymers was for PLA 1.61…2.18 MPa·m3/kg, for PET-G – 1.15…1.41 MPa·m3/kg. The specific impact strength for PLA is 751.6…774.2 J·m/kg, for PET-G – 571.6…583.0 J·m/kg. The specific endurance for PLA was 1.75…2.76 kPa·m3/kg, for PET-G – 3.0…3.10 kPa·m3/kg.

Now in agricultural production there are significant changes in the fleet of equipment due to the renewal of the material and technical base with improved parameters for quality, reliability, durability and operability in difficult operating conditions. However, the manufacturing industry still has a large number of outdated equipment that requires modernization through optimal design of machine components and parts. So, in the process of feed preparation, closed-type grain crushers are widely used, working on the principle of suction of the source material and injection of the finished product. This type of crushers undergoes significant abrasive wear of working bodies (drums, hammers, sieves, etc.) due to their suboptimal geometric shape of transition surfaces, where local stresses accumulate, as well as in areas of contact of parts with particles of gas-dispersed material. The blades of the drum wheel are subjected to particularly severe wear, for the restoration of which significant material costs are required during major repairs. The paper presents theoretical studies of contact stresses during wear of working surfaces, a criterion and condition for the optimal position of the blade are proposed. The optimal position of the blade has been determined - it must be positioned at an angle of 10 ° to the axis of the drum wheel. The results of field tests of the upgraded crusher allow us to conclude that the reliability indicators (durability of the blade drum and reliability of the crusher) increase by more than 3 times.