Introduction. The bakery industry is an agricultural industry of high-level processing of raw materials focuses on the end-consumer. In the production of bakery products one of the operations of the technological process is performed by dough dividers of vacuumpiston type, whose service life is 30‒40% lower than the normative. The most promising method for restoration of worn parts of the suction mechanism is electrospark processing. When selecting the electrode material, it is important that they have not only low erosion resistance, but also high tribotechnical properties. Aim of the Article. The article deals with problem of selecting electric coatings to reduce wear of working surfaces of suction mechanism parts during repair of vacuum piston-type dough dividers. Materials and Methods. The analysis of the properties of electropark coatings was carried out by nondestructive testing methods using modern research equipment; the results were processed using the Compass-3D program. Results. There are determined the values of physical, mechanical, frictional and tribotechnical properties of electrospark coatings made of BrOS10-10 bronze and Kh15N60 alloy. The total wear rate for BrOS10-10 bronze coating was 8,3 ∙ 10‒12, and for Kh15N60 alloy 15 ∙ 10‒12. Discussion and Conclusion. Total wear rate on the friction machine of bronze coated samples is lower than that of basic friction pair in 1.4 times, and of alloy coated samples ‒ higher in 1.26 times. Adding of MODENGY solid-lubricant coating to the coating from the alloy reduces its abrasion ability by 3 times, and the total wear rate ‒ by 1.34 times in comparison with the base friction pair. The used calculation-experimental method showed low wear rate of electrospark coatings of bronze and alloy in relation to the material of parts of the suction mechanism of vacuum-piston-type dough dividing machines.

The dimensional barrier to increasing the thickness of electrospark coatings with increased contact continuity is addressed. The limitation on coating thickness is analyzed, and existing remedies are reviewed. Conditions in which thick coatings with no less than 80% contact continuity may be produced are identified, in the case of a BrKMts3-1 bronze electrode and samples of gray cast iron.

Introduction. Agriculture includes one of the branches of raw material processing, the final product of which is bread making. At the same time, the most complex operation in the technological chain of bread making is the division of the finished dough into billets of the same mass. This operation is performed by vacuum-piston type dough dividers. Under operating conditions, the service life of dividers is 30-40% lower than the manufacturer’s stated. In the technical documentation there is not point of the limit state of dividers, so they continued to be used with high costs of technological materials that determine the cost of the finished product. The purpose of the work is to determine the criterion for evaluating the performance of dough dividers and the limit value of the criterion. Materials and Methods. Evaluation of the technical condition of vacuum piston type dough dividers was based on the edible oil consumption of food line WP 32 (manufacturer AIMOL). To measure the mass of the consumed oil and the mass of the dough pieces, scales were used with an accuracy of ±0.1 g and ±1 g, respectively. Results. Based on the results of the analysis of the operation principle of dough dividers, the criterion of efficiency is called the oil consumption, which is responsible for the accuracy of weighing the dough through creating a vacuum in the suction chamber when filling gaps in the coupling of parts. When evaluating the technical condition of machines by manufacturing 300 test pieces configured for a mass of 500 g the maximum oil consumption is obtained equal to 218 g. According to the maximum oil consumption, the allowed oil consumption is determined to be 109 g. Discussion and Conclusion. It is established that at bakery enterprises, about 30% of used dough dividers have an over-extreme limit state and the accuracy in weighing the dough cannot be restored by increasing the oil consumption. However, starting from the oil consumption above the allowed value of 109 g, the machines need major repairs. The obtained values of the limit and allowed state of dough dividers are widely used in bakery enterprises to assess their technical condition.

Production costs and product quality in manufacturing depend directly on tool life in cold and hot machining of metals and alloys. The types of surface failure in tools are considered in the present work. The potential for increasing their wear resistance by electrospark coating deposition is noted. The dependence of the relative coating thickness on the relative limiting carrying capacity of the coating is determined for surface hardening of forged tools. The influence of the electrode composition on the resulting surface properties is analyzed.

Introduction. Nowadays, vacuum-type dough dividers are used in industries with a production volume of up to 4,000 loaves per day. In the dough divider operation, due to wear of the working surfaces of the piston, chamber, and drum, the gap between them goes beyond the value equal to 50 microns, which provides vacuum in the suction chamber. As a result, the suction process becomes unstable; the dough divider disturbs the weight accuracy of bakery goods. Repair of such equipment is carried out mainly through a full or partial replacement of worn parts and assemblies with new ones. To increase their durability, there is a need to develop a new highly efficient technology with the restoration of worn part surfaces using the welding and surfacing methods.Materials and Methods. A new technique of determining the number of objects for research using the “STATISTICA” program is presented. Wear surfaces of the vacuum dough divider parts are determined.Research Results. Micrometric studies of the dough divider components were carried out. They showed the presence of appreciable size distortions due to the local wear of the working surfaces. In this case, a side gap between the suction chamber and the main piston and between the drum and the suction chamber is 6 times higher than the permissible one, and a vertical gap between the division box and the piston exceeds the permissible gap by more than 10 times. Wear of the working surfaces of the dough divider parts is local in nature, while the range of values is as follows: for the main piston, it is 10-200 microns; for the gaging piston, it is 250- 900 microns; for the suction chamber and division box, it is 300-400 microns; for the drum surfaces, it is 280-300 microns.Discussion and Conclusions.The conducted micrometric studies showed the presence of appreciable size distortions due to the local wear of the working surfaces. Based on the results obtained, it can be argued that the most productive and economically viable technique for the restoration of worn surfaces of dough divider parts is, for example, the electrospark machining.