Advanced Materials Research Vol. 801

Abstract: 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.

Abstract: 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.

Abstract: Failure mode and effects analysis (FMEA) was performed in RIBE Slovakia, k.s. (limited partnership) in Nitra, Slovakia. Analysis was done in the process of cold forming where potential errors (failures) were identified. Subsequently, there was assigned a mark in the FMEA form expressing severity, frequency and undetectability, and a risk priority number (RPN) was calculated. If the risk priority number (RPN) is too high, corrective measures are proposed and adopted in order for the risk to be minimized or completely eliminated.

Abstract: In the last years and also due to today's economic situation and crises in the world, each organization is looking for a continuous improvement of processes and business performance. The major task of each production organization or services is the saving of money, which is lost because of scrap, long cycle times, wrong process maps and inventory differences. The goal of this article is to describe the implementation of Six Sigma in a production organization focusing on the production of interior parts for the automotive industry. During the summer time, there was delamination between thermoplastic foil and plastic substrate, which caused increasing of scrap, additional substandard works as well as the risk of quality complaints from customer. Six Sigma and DMAIC cycle were used to find root causes and to implement permanent corrective actions to remove this kind of problem from production.

Abstract: If organizations want to be successful, they must quickly adapt to changing conditions in a competitive environment, must be flexible and must quickly resolve situations and problems occurring in organization. We use different tools and methods to solve these problems. One of these methods is Eight Disciplines Problem Solving (8D). The 8D method is a structured problem solving process. This method helps to correctly and timely solve problems. It is used when the cause of problem is unknown or when the solution to problem is beyond the capabilities of a single worker. This method is also used to improve products and processes

Abstract: 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].

Abstract: Presented study deals with the resistance of a surface layer created by laser surfacing. Hard surfacing metal powder of type UltrAloy 10611 with a 50 % share of tungsten-carbide particles was used for laser surfacing. Created weld was tested in laboratory conditions (hardness HRC) as well as in field soil conditions (relative wear resistance). Obtained results confirm that this added material is suitable for use in conditions where high abrasive wear is present

Abstract: 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.

Abstract: Every car needs for operation, if possible, the highest quality fuel. Fossil fuels produced from crude oil by conventional technology are being increasingly replaced by alternative fuels. It is caused by new technologies that allow combustion of such fuels and, at the same time, provide economically more efficient operation of cars. From the perspective of ecology, they are also of great importance when it comes to meeting the strict emission standards of the European Union. The experiment compares two types of alternative propulsion with LPG and CNG at selected makes of Fiat cars with 1.4 litre engines. These engines can also utilize conventional fuels – petrol and are mass-produced directly from the factory. The measurements themselves were carried out during predetermined driving cycles such as urban, extra-urban and highway. All the three categories of measurements were carried out under normal driving conditions in a standard manner in compliance with all traffic regulations. Based on all measurements obtained from both engines with LPG and CNG propulsion, we found that the car with the LPG engine became economically more advantageous. The benefit was found in expenses return with this system as well as in measured consumption, prices and availability of filling stations.