FEM SIMULATION OF DEEP DRAWING PROCESS OF ALUMINIUM ALLOYS

This paper presents results of research with FEM simulation of sheet metal forming process. The two types of aluminium alloys from 5XXX and 6XXX series, which are used in automotive industry, were compared. The computer simulation and numerical analysis of deep drawing cup test were used to predict the ability of the forming of these alloys. The plasti-city model Hill'90 was used for stamping simulations. The results of nu-merical simulation were validated by real experiment using sheet metal testing machine Erichsen 145-60. Both results were compared with regard to prediction accuracy in changes of thickness and ear profile

Термогравіметричні дослідження композитів на основі сумішей поліпропілену та модифікованого поліаміду

We established in the present work the regularities for obtaining homogeneous nanocomposites based on the mixture of PP/PA-6 with montmorillonite modified using PVP. In these nanocomposites, PA-6 and MMT contribute to the increase in thermal resistance of the material, while PVP improves compatibility between polar PA-6 and hydrophobic PP.The goal of the present work was to investigate by applying the methods of thermogravimetric analysis a correlation between thermal characteristics of the newly-created nanocomposites based on the mixture of PE/PA-6 with montmorillonite, modified using PVP, and to determine the optimal composition of a nanocomposite with enhanced thermal resistance and a wide temperature interval of the viscous-fluid state.On the basis of experimental data, it was found that the mixtures of polypropylene with polyamide modified by the montmorillonite-polyvinylpyrrolidone mixture are distinguished by the higher thermal resistance compared with the starting PP. It is established that at a content of the modified polyamide in the mixtures with polypropylene within 30 % by weight, samples of the composite are characterized by the highest thermal resistance ‒ weight loss of such composites in a temperature range of 218‒322 ºC is only 7.1 %, temperature of the onset of thermo-oxidation destruction is 300 ºC. It is shown that the developed nanocomposites have wider temperature intervals of the viscous-fluid state – 126–300 ºC. This makes it possible, by changing the modes of processing, to influence the structure and properties of products, especially taking into account the difference in crystallization of the material depending on the conditions and the method of processing. It is established that the most suitable for application and processing is the mixture of polypropylene with modified polyamide in the ratio 70:30 % by weight, respectivelyМетодами дифференциально-термического, термогравиметрического и дифференциально-термогравиметрического анализов исследованы композиты на основе смесей полипропилена с полиамидом, который предварительно модифицирован монтмориллонитом, интеркалированным поливинилпирролидоном. Показано, что смеси полипропилена с модифицированным монтмориллонит-поливинилпиролидоновой смесью полиамидом отличаются повышенной термостойкостью. Установлено, что при содержании модифицированного полиамида в смесях с полипропиленом в пределах 30 % масс. образцы композита характеризуются найвысшой термостойкостьюМетодами диференційно-термічного, термогравіметричного та диференційно-термогравіметричного аналізів досліджено композити на основі сумішей поліпропілену з поліамідом, котрий попередньо модифікований монтморилонітом, інтеркальованим полівінілпіролідоном. Показано, що суміші поліпропілену з модифікованим монтморилоніт-полівінілпіролідоновою сумішшю поліамідом відзначаються підвищеною термостійкістю. Встановлено, що за вмісту модифікованого поліаміду в сумішах з поліпропіленом в межах 30 % мас. зразки композиту характеризуються найвищою термостійкіст

EFFECTIVENESS OF CELLULAR INJECTION MOLDING PROCESS

In a study of cellular injection, molding process uses polyvinylchloride PVC. Polymers modified with introducing blowing agents into them in the Laboratory of the Department of Technologies and Materiase of Technical University of Kosice. For technological reasons, blowing agents have a form of granules. In the experiment, the content of the blowing agent (0–2,0 % by mass) fed into the processed polymer was adopted as a variable factor. In the studies presented in the article, the chemical blowing agents occurring in the granulated form with a diameter of 1.2 to 1.4 mm were used. The view of the technological line for cellular injection molding and injection mold cavity with injection moldings are shown in Figure 1. The results of the determination of selected properties of injection molded parts for various polymeric materials, obtained with different content of blowing agents, are shown in Figures 4-7. Microscopic examination of cross-sectional structure of the moldings were obtained using the author's position image analysis of porous structure. Based on analysis of photographs taken (Figures 7, 8, 9) it was found that the coating containing 1.0% of blowing agents is a clearly visible solid outer layer and uniform distribution of pores and their sizes are similar

RESEARCH ON THE CONTENT AND FILLER TYPE ON INJECTION SHRINKAGE

The paper presents the phenomenon of injection shrinkage. The definition of shrinkage and shrinkage types are presented. The main factors affecting shrinkage value of injection-molded part are discussed. Based on the experimental tests conducted using injection-molded parts made from polypropylene filled with glass fiber and talc, the dependence of injection-molded part shrinkage on filler content and selected parameters of the injection molding process has been determined

EFFECTIVENESS OF CELLULAR INJECTION MOLDING PROCESS

In a study of cellular injection, molding process uses polyvinylchloride PVC. Polymers modified with introducing blowing agents into them in the Laboratory of the Department of Technologies and Materiase of Technical University of Kosice. For technological reasons, blowing agents have a form of granules. In the experiment, the content of the blowing agent (0–2,0 % by mass) fed into the processed polymer was adopted as a variable factor. In the studies presented in the article, the chemical blowing agents occurring in the granulated form with a diameter of 1.2 to 1.4 mm were used. The view of the technological line for cellular injection molding and injection mold cavity with injection moldings are shown in Figure 1. The results of the determination of selected properties of injection molded parts for various polymeric materials, obtained with different content of blowing agents, are shown in Figures 4-7. Microscopic examination of cross-sectional structure of the moldings were obtained using the author's position image analysis of porous structure. Based on analysis of photographs taken (Figures 7, 8, 9) it was found that the coating containing 1.0% of blowing agents is a clearly visible solid outer layer and uniform distribution of pores and their sizes are similar

MODERNIZATION OF TECHNOLOGICAL LINE FOR CELLULAR EXTRUSION PROCESS

In recent years, cellular extrusion of polymers has been one of the fastest growing processing methods. It is used especially to obtain sections, bars, pipes and cellular coatings free from strains on the product surface, displaying reduced density and minimum shrinkage, at the same time maintaining similar properties of products extruded in a conventional way. In order to obtain cellular structure, product properties are modified by application of proper plastics or adding blowing agents. The article provides a description of manufacturing processes of cellular product. It gives characteristics of blowing agents used in the extrusion process and of processing conditions. Also, it discusses selected results of examined properties of the obtained cellular products. As part of the modernization of the cellular extrusion technology the extrusion head was designed and made. During the designing and modeling of the head the Auto CAD programe was used. After the prototyping the extrusion head was tested. In the article specification of cellular extrusion process of thermoplastics was presented. In the research, the endothermal chemical blowing agents in amount 1,0% by mass were used. The quantity of used blowing agent has a direct influence on density and structure of the extruded product of modified polymers. However, these properties have further influence on porosity, impact strength, hardness, tensile strength and another

Effect of Nature and Amount of Polypropylene Composite Filler on the Productivity of Extruder with the Cylinder Equipped with Grooves

The effect of grooves number in the feed section and screw length as well as filler nature and content on the productivity of single-screw extruder has been examined. Compositions based on polypropylene with glass fibers, talc and chalk were used for research. It is established that the number of grooves in the feed section and the length of the screw differently affect the productivity of a single screw extruder depending on the nature and content of the filler. This effect is shown to be most significant for polypropylene compositions with mineral powders (talc and chalk)

Rheological Properties of Compositions Based on Modified Polyvinyl Alcohol

The paper is dedicated to development of a method for producing structured waterproof films based on polyvinyl alcohol (PVA) and montmorillonite-polyvinylpyrrolidone mixture (MPM) to research the impact of borax, pH-environment and MPM content on the rheological properties PVA solutions and water absorption capacity of films based on them. By experimental studies have been established that the montmorillonite- polyvinylpyrrolidone mixture significantly affects on viscosity the characteristics of the solution polyvinyl alcohol provided their mixing in the ultrasonic field. Composition of traces of sodium tetraborate in the aqueous solution eminent by the highest rates of viscosity. Also, designed compositions considerable influence pH at the viscosity, particularly compositions obtained in weakly alkaline environment with higher values of relative viscosity than compositions obtained in neutral and acidic environments. Simultaneously, is the best water resistance and mechanical properties of films obtained in an acidic environment. The optimum from the standpoint of durability and water resistance is a composition of PVA:MPM = 12:1 and because, depending on the contents of the MPM and pH characteristics films based on PVA can be adjusted over a wide range, which would expand the scope