Jozef Žarnovský

Thermoset Composite on Basis of Recycled Rubber

The paper describes the mechanical qualities of thermoset – epoxy resin filled with recycled rubber in the form of micro-particles. Such an application of waste can be regarded as material usage which should be preferred to other ways of waste handling. Micro-particles of recycled rubber affect the mechanical qualities of polymer in which they are dispersed. The paper quantifies cohesive and adhesive properties of the filled epoxy resin. Filling polymers – thermosets with waste fillers saves costs, it does not burden the environment, and it is inexpensive. The results described in this paper can lead to enlarging the application areas of recycled rubbers. As the filler, recycled rubber gained by the process of an ecological disposal of tyres by Gumoeko, s.r.o. (private limited company) was used.

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].

Recycling of Polyamide from Scrap Tyres as Polymeric Composites

Muller M., Žarnovský J., Drlicka R. (2015): Recycling of polyamide from scrap tyres as polymeric compos ites. Res. Agr. Eng., 61 (Special Issue): S79–S83. Rubber granulate, metal waste and textile waste (polyamide fibres) come into the mechanical process of waste tyres recycling. The pollution and degradation processes are problematic in using of secondary raw material. The matrix was in the form of three various adhesives in testing – two-component epoxy adhesives and a polyester adhesive. The filler was in the form of textile waste (polyamide fibres) from the process of tyres recycling containing approximately 10–12% of rubber granulate. The filler was added in app. 15% of weight ratio into the matrix. The aim of the research was to determine a possible utilisation of unsorted textile waste from the process of tyres recycling in the area of poly meric composite systems.

Boroscopy Application in Assurance of Technological Equipment Operational Capability

This paper is focused on an emphasis of the preventive maintenance effect on reliable and safe operation of technological equipment, in view of technical diagnostics. Problems of the boroscopy as a diagnostics method providing fast information acquiring of inner parts of technological equipment turbomachinery RB211 DLE assembled in combined cycle gas turbine (CCGT) in selected company [. Observations were focused on high pressure axial compressor, being the main part of monitored technological system. From quality point of view the paper provides new perspective of internal inspection of technological equipment covering possible damages locating and qualifying of qualitative characteristics of equipment inner parts. The problems solved were based on particular practice demands and it reflects state-of-art in concerned scientific field [.

Air Quality Improvement by Reduction of Gas Turbines Emissions

The most serious sources of the air pollution are the studied company compressor stations of the transit system equipped with the number of gas turbine. [1] Pipeline parts have smaller degree of importance and gas boiler and emergency resources of thermal and electric energy have minimum influence. These sources emit into atmosphere mainly nitrogen oxide, carbon monoxide, paraffine with the exception of the methane and unburned rest of the fuel. In comparison with these emissions are emissions of sulfur dioxide and the solid contaminations substances minimal, insignificant. Along with reduction of transit performance deploys the company in recent time significantly more energy effective power units for transit of natural gas. These drive units are mainly gas turbines burning part of transported natural gas. [2] Russian natural gas is used as a fuel which in comparison with the others kinds of fuels contains only little amount of sulfur and contain almost no As, Na and heavy metals. The main parts of combustions are CO2, CO, NOx which are products of burning and N2, O2, untouched atmosphere elements. CO and NOx are considered to be harmful substances.

Seven New Quality Management Tools

This contribution focuses on solving a customer complaint accepted by an organization for manufacturing of automobile seats. The occurrence of nonconformity and causes of undetected nonconformity in the manufacturing process of automobile seats is solved by seven new quality management tools. Causes, effects, activities leading to elimination of the problem, remedies and precautions for possible problems within solution implementation, and time schedule with individual reserves are defined. Results lead to solving the issue both on the part of supplier and on the part of the organization for manufacturing of automobile seats

Analysis of Physical Effects in Cutting Machining

This contribution focuses on hole drilling into grey cast iron and steel 11 523. The most used method of hole machining is the one using a screw drill HSS to reach the accuracy class from IT 11 up to IT 14. Surface roughness ranging between Ra 3.2 μm and Ra 6.3 μm depends on the parameters of the drill used and drilled material. An emphasis is put on the accuracy of shape and dimension as well as on meeting the tolerance limits of holes [1,2,3,4,5]. In most cases, it is possible to reach those conditions using the common methods of hole drilling. Finishing such as roughing, reaming and countersinking is used for meeting high-quality requirements [6,7,8,9].