Jozef Dobránsky
Technical University of Košice
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Publication
Featured researches published by Jozef Dobránsky.
Advanced Materials Research | 2013
Jozef Dobránsky; Rastislav Mikuš; Juraj Ružbarský
This paper deals with the verification of thermoplastic flowing when manufacturing plastic products by injection moulding used in the consumer industry. An analysis was performed by Plastic Insight, which is used for the determination of flow properties of thermoplastic materials. A good knowledge of flow properties of these materials enables a very good starting position for the design of thermoplastic products made by the injection moulding technology [1,2]. The task of this simulation was the comparison of injection parameters of a mould, with and without cooling of channels. Simulated thermoplastic material is used for the manufacture of ribs in washing machine drums. The tested material was polypropylene.
Applied Mechanics and Materials | 2013
Luboš Bĕhálek; Jozef Dobránsky
Paper deals with the diagnosis of operating conditions for injection moulding tools. Paper specifically deals with the conformal cooling of injection moulds for its production is using the direct metal laser sintering method. It´s quite modern method about injection mould cooling system design to improve cooling intensity. Paper also deals with the evaluation of the temperature fields in the area of the mould shape parts in comparison with the common cooling system with drilled channels namely at using steel or copper alloys for punch production. Moreover there is also evaluated cooling method influence on properties and also injection part morphological structure by methods of wide angle X-ray scattering and differential scanning calorimetry.
Advanced Materials Research | 2011
Emil Ragan; Petr Baron; Jozef Dobránsky
Advantageous properties of plastic materials, low investment costs for a production, cheap and productive processing method were given the rapid development of plastic materials. In this time injection molding technology is the most using technology for processing plastics in our country. Quality of the plastics processing depends mainly on the quality of material and preparing it for production. The first step in the processing of plastic by injection molding is dosing of granulations from hopper of injection machine unit. Task of this contribution is to theoretically describe a pneumatic method for transport of granulations in injection molding machine.
Key Engineering Materials | 2015
Jozef Dobránsky; Petr Baron; Eva Vojnová; Dušan Manduľák
The decision-making process in the stage of technical preparation, during the planning of logistic portfolio and production queries is marked by individual decisions that may be affected by errors causing in extreme cases the fatal consequences. The tools of computer simulation help to eliminate the negative effects of bad decision-making. This article describes the usage of computer simulation in process of optimization of material flow using an appropriate spatial deployment of production facilities. The triangular method was used for the optimization of the spatial deployment. The factors to create the triangular method were obtained from the final report of the simulation of the current production state in the assessed facility. Subsequently a simulation of the proposed optimization variants was conducted. Based on the selected criteria, the most suitable alternative was chosen for the enterprise.
Applied Mechanics and Materials | 2014
Jozef Svetlík; Petr Baron; Jozef Dobránsky; Marek Kočiško
This paper describes attributes of newly designed variant approach of computer support system of technological preparation of production. Knowledge system for automation of production of technological documentation was developed for technology of surface processing of metal. The paper describes the design of coding system for sorting mechanical parts into groups with similar mechanical parts, either by their shape, dimensions or used technology. Subsequently, it points out to attribute of the system – uploading and modification of sample technological documentation.
Key Engineering Materials | 2015
Jozef Dobránsky; Luboš Bĕhálek; Petr Baron
Paper deals with simulation analysis of thermoplastic flowing in plastics product. As there is a demand in plastic products, plastic industries are growing in a fastest rate. Hence plastic injection molding process begins in manufacturing of complex shapes, in this process optimum gate location is one of the important criteria in mold design. Knowledge of ideal flow properties of thermoplastic materials give us a very good starting position for design of thermoplastics products which will be made by injection molding. By simulation software Plastic Advisor was compared injection parameters for the mold with varying gate locations. Simulated thermoplastic product is made from polycarbonate and is using for the drum washing machine as console window.
Key Engineering Materials | 2015
Petr Baron; Jozef Dobránsky; Martin Pollák; Tomáš Cmorej; Marek Kočiško
Calculation of the machining parameters is one of the basic routine operations carried out before initializing the work and technological operations on a machine tool. Basis for calculating these parameters is obtained from the technical documentation in the form of rules, tables, catalogues and company literature. It can be concluded that this is a routine activity which represents a significant proportion of the activities performed before actual production of the product. It is exactly the routine activities that are possible to underpin and process well with the help of computers and appropriate application equipment. This contribution describes the design and implementation of a knowledge based system of calculation of the processing and operational machining parameters with the possibility of parameter correction with regard to specific technological equipment. The result is the obtaining of an optimal machine setting for machined range of products with a consideration for the production efficiency, durability of the cutting tool and the possibility of reusing the archived operational parameters.
Applied Mechanics and Materials | 2013
Peter Čačko; Tibor Krenický; Jozef Dobránsky
The article studies, based on the evaluation of the experimental research, effectiveness of independent and combined interaction of selected methods when diagnosing bearing of the mechatronic device in course of 6 months. During this time the general overhaul of the device was carried out, where the measurements, analyses and evaluations were focused on run-in and a shorter after run-in period of the bearing.
Applied Mechanics and Materials | 2014
Jozef Dobránsky; Petr Baron; Marek Kočiško; Eva Vojnová
Present article deals with assessing the influence of moisture content in thermoplastic material on rheological properties of material. The measurements were carried out on samples of hygroscopic plastics, i.e. plastics that tend to absorb moisture from the surrounding environment. Moisture in plastic material before its processing can have negative influence on physical or thermal properties of a product and can devalue visual aspect of the end product, thus these plastics have to be dried before their processing. Observed samples of materials were placed in three different rooms and measurements of Melt Volume-Flow Rate of thermoplastics were carried out at precisely determined intervals. Moisture content in material was determined by Mettler Toledo HB43-S moisture analyzer. To determine the influence of moisture content on rheological properties of material, a method of determination of Melt Volume-Flow Rate (MVR) of thermoplastics was used. The measurements were performed by using Termo Haake Meltflow MT etxrusion plastometer.
MM Science Journal | 2016
Jozef Dobránsky; Frantisek Botko; Eva Vojnová
Presented article is focused on heat transfer in injection mold, which is designated for plastic parts production. As experimental part was selected two components injection mold with hybrid cooling. Molds cooling system was in two variants: conventional and conformal cooling. In subsequence three variants of cooling were simulated. First variant contained conventional cooling system manufactured by drilling technology. Second variant was designed with conformal cooling system which copies shape of the molding. Third variant consisted of conventional and conformal cooling combined. Simulation procedure was performed in simulation software ANSYS. Temperature presets for injected molding was set according to used material Makrolon 2805. Heat transfer between individual parts of mold was evaluated using individual probes.