Juraj Ružbarský

Comparison of Cooling Variants by Simulation Software

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.

Using Recycled Rubber Particles as Filler of Polymers

One of a way of a material utilization of a rubber waste originated at a recyclation of tyres is its inclusion into polymeric materials. The paper describes chosen mechanical properties of an epoxy adhesive and polyurethane filled with the waste rubber. The waste rubber was gained as one of outputs of a recycling line of a firm Gumoeko, Ltd. The filler presence influences resultant mechanical properties and decreases a price of gained materials. Defining of mechanical properties enables to specify possible application areas.

Degradation Process in Area of Connecting Metal Sheets by Adhesive Bonding Technology in Agrocomplex

From the production essence point of view the necessity to create constructional bonds comes into being. In the sphere of connecting thin metal sheets it is suitable to apply the adhesive bonding technology. A significant branch is an agricultural production which is distinguished for many very degradable environments. The aim of experiment is to study and experimentally verify the degradation processes influence running in the adhesive bonds. The interval of the exposition of the adhesive bonds to the degradation environment was 0, 2, 4, 8, 16 and 32 weeks. Secondarily, the influence of various contaminants on a rise of the corrosion at the constructional carbon steel S235J0 was evaluated. Another aim is to determine by means of statistical methods ANOVA an influence agreement of single liquid contaminants types based on industrial and mineral fertilizers (Ammonium sulphate, NPK, DAM and Slurry).

Die Casting Defects of Castings from Silumin

The production of die castings cast into a metal mold has in recent years achieved an expansive growth in the volume as well as the range of production and that is particularly in aviation and automobile industry. A primary criterion for achieving reliability, efficiency and quality of production is to ensure minimization of the castings defects occurrence. For this reason it is necessary to describe the type, scope and frequency of die castings defects and to define the cause of their occurrence.

Optimization of Parameters in the Compression Moulding Process of Thermoset Products

This article analyses the optimization of technological and machining parameters when processing thermosets. These parameters were optimized by various tests, e.g. cooking and pressure test. The reason for using the cooking test is that thermosets are low molecular weight compounds and this test provides a picture of their ability to absorb the liquid. The importance of optimizing the parameters is in the fact that after moulding of thermosets, it is not possible to melt and mould them again. Therefore, every moulded piece that does not satisfy the quality conditions is a reject and loss for the company [1,2]. The article shows limiting parameters and contains proposed optimizations for moulding in order to avoid rejects and damage to machines. The three main technological parameters of moulding are examined, namely compaction pressure, mould temperature and moulding time. The external parameter is thermoset temperature [3,4,5].

Comprehensive Durability Identification of Ceramic Cutting Materials in Machining Process of Steel 80MoCrV4016

Specification cutting tools durability made of cutting ceramic in machining process of steel 80MoCrV4016 is very important for economics of small and medium-sized enterprises, because cutting tool durability is factor that significantly affects the budget of these enterprises. This problematic is determined for small and medium-sized manufacturers of bearings, because steel 80MoCrV4016 is most commonly used for production of bearings. Durability of cutting tool defines lifetime of this cutting tool and it determines its suitability for select technological operation. Especially for cutting ceramic is necessary to define durability dependence on available set of cutting speeds and to determine lifetime of tools made of cutting ceramic. Technical science defines a lot of different factors, that they may be cause of shorter cutting tool lifetime. For increase cutting tool durability is necessary maximally possible elimination of these factors. Determination of cutting tool durability is very important, because provides comprehensive information how to determine appropriate technological conditions for selected cutting tool. In engineering is for determination of cutting tools durability used T-vc dependence. The article describes process how to create durability dependence for cutting tools made of cutting ceramic by means of T-vc dependence in machining process of steel 80MoCrV4016.

Modelling of the Anisothermal Phase Transformation of Austenite by Electromagnetic Sensor

The characterization of steel microstructures is an important tool for metallurgists as mechanical properties are controlled by microstructural parameters such as grain size, phase balance and precipitates. This paper describes a model of the phase transformation of tool steel CSN 41 9436. Each of the experimental data was observed by electromagnetic sensor. The mathematic model was developed for an optimizing of tool steel heat treatment. The model was developed from one experiment and next experiments were for an evaluation of the model. A model can be satisfactory used for graphical form of the austenite phase transformation.

Introduction into the Issue of Water Jet Machining

The ways of searching for methods of increase of efficiency of the process of machining by water jet, of shortening the time inevitable for cutting the individual components with preservation of the quality of the machined area or of reduction of vibration size have not been completed yet. Vice versa, the technology—besides the unlimited assortment of sectile material—disposes a tool without negative effect upon a workpiece or environment and has become a progressive technology in the course of the last years. The infinite or progressive technology of machining by abrasive water jet has gained an importance by adding the abrasive substances. High speed of outflowing water jet with admixture of abrasive allows intensive, economic and ecological machining of almost all industrial materials.

Methodology of Measurement and Examining Methods

The methodology of measurement contains the basic information on performance of measurement of the magnitude of acceleration of technological head vibrations of the selected technical system in the time and frequency domain without the use of abrasive fraction and with the application of narrow fraction of abrasive. The chapter is divided into several basic parts:

Assessment of Measurement of Vibration Sizes

The files of the individual measurements of the structure mentioned in Sect. 5.2.1 contain the assessment of magnitudes of amplitudes of acceleration of the technological head vibrations along with the related frequency spectra under the change of abrasive mass flow, type of abrasive and of narrow fraction of abrasive grain in case of machining of abrasion-resistant steel of K 13—HARDOX 500 type.