Róbert Drlička

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.

CAPABILITY ASSESSMENT OF MEASURING EQUIPMENT USING STATISTIC METHOD

Capability assessment of the measurement device is one of the methods of process quality control. Only in case the measurement device is capable, the capability of the measurement and consequently producƟon process can be as‐ sessed. This paper deals with assessment of the capability of the measuring device using indice s Cg and Cgk.

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.

Boron Effect on Mechanical Properties and Structure of Steel STN 41 5230 Surface Layer

This paper deals with the possibility of applying controlled diffusion processes in the remelting of steel surface layers using the electric arc of non-consumable electrode in the environment enriched with selected elements. The objective was to achieve an increased wear resistance. Boron was used in experiments as an alloying element. An assumption was stated in the experiment design that environment dissociation and ionisation can be achieved using electric arc, allowing diffusion processes initiation in the surface layer of remelted steel. Conditions for hard and stable structures formation with required properties should be achieved by surface layers enriching. Steel grade STN 41 5230 was used in experiments. Hardness and relative abrasive wear resistance values were measured on samples after remelting, being crucial as for required properties of surface layers. Not only hardness values were measured in the remelted layer but also their course inwards the material up to reaching the depth of base material not affected by heat. The metallographic analysis of remelted samples was made as well. A significant increase of parameters observed in the boron remelting environment was found. The dependency of the environment effect on the change of properties and boron content in the remelting environment was observed.

Effectiveness of Hard Turning

Hard turning is a turning operation performed on hard materials (hardness more than 45 HRC) in order to reach surface roughness close to that obtained in grinding. The development of this technology was accompanied by the development of new cutting materials such as cutting ceramics, cubic boron nitride and polycrystalline diamond. Especially cubic boron nitride has found its use in hard part turning operations because of its characteristics. However, new cutting materials result in new questions, which researchers are trying to solve. The major consideration for a user of this relatively new technology is the quality of parts produced and how the new cutting material will behave during machining. This paper aims to document and describe the process of wear on the cutting edge of a tool made from cubic boron nitride of a different grade and with a different geometry of the cutting edge, and its influence on surface roughness and quality. Wear was documented by a digital microscope with measurement option. Surface roughness was measured by a roughness meter. A notable observation from this research is that the flank wear of the cutting tool has a large impact on the quality of machined parts (especially surface finish and surface integrity) [1].