Browsing by Author "Kočiško, Marek"
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- ItemSolving depressions formed during production of plastic molding(Technická Univerzita v Liberci, 2015) Dobránsky, Jozef; Baron, Petr J.; Kočiško, Marek; Běhálek, Luboš; Vojnová, EvaThis article deals with improvement of design properties of molded plastic parts. It can be achieved by modifying construction of metal injection mold and optimization of parameters in injection process. The subject of our examination was depressions formed on molded plastic parts which are inacceptable in the process of approval. The problem which has arisen was solved in two phases. The first phase consisted in alteration of injection mold design – enlargement of injection molding gate. In the second phase, we have changed the location of injection molding gate. After performing constructional modifications, new molded plastic parts were manufactured and assessed. © 2015, METALURGIJA. All Rights Reserved.
- ItemThe influence of the use of technological waste on the mechanical behavior of fibrous polymer composite(2019-06-01) Dobránsky, Josef; Běhálek, Luboš; Baron, Petr; Kočiško, Marek; Dulebová, Ľudmila; Doboš, ZigmundThe experiment conducted describes the effect of the use of technological waste on the mechanical behavior of a composite reinforced with short-length glass fibers. This requirement was postulated in course of cooperation with a manufacturing company active in producing components for the automotive industry. In its production of components, the company generates a large volume of technological waste, which is not re-processed at the moment. The material selected for the experiment was Ultradur B 4406 G6 Q717, which is the most frequently one used by the company. It is a composite with a polymeric matrix of PBT and a filler with short glass fibers, accounting for 30% of its volume. Mechanical properties were tested from both, the short-term view, and in terms of the life of the parts. The value of the tensile strength limit decreased by 13.3% in total, correlating with the amount of the recycled material added. Upon exposure to elevated temperature, the tensile strength limit increased by 13%. The modulus of tensile elasticity in short-term tests dropped by 5.4% and increased by 2% upon exposure to elevated temperature. Electron microscopy was used to evaluate interaction at the interstage. A similar trend was noted in evaluation of the flexural strength. The flexural strength dropped by 16.4% in total, correlating with the increase in the amount of recycled material added. Upon exposure to elevated temperature, the flexural strength increased within the range of 0.4-10.4%.