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Technology of injection molding of thermoplastic test specimens
Khamzin, Yersin ; Petruš, Josef (referee) ; Kučera, František (advisor)
The diploma thesis focuses on the optimization of technological parameters of plastic injection molding and the study of the influence of technological parameters on the quality of molded test specimens’ type 1A. The quality of molded parts for 3 types of polypropylene (PP) with different melt flow rate (Mosten GB 002, Mosten GB 218, Mosten MA 230) and 1 type of polystyrene (PS) (Krasten PS GP 154) was evaluated in terms of dimensional stability and weight. The contribution of software for modeling the plastic injection molding process was evaluated in this work. SOLIDWORKS Plastics software was used to optimize technological parameters. The construction of the bodies, mold and cooling system was constructed, and test bodies were produced on the basis of parameters obtained from the simulation of the injection molding process. Their quality parameters were compared with a 3D model and for each of the studied materials the optimal technological parameters were selected in terms of quality and the degree of influence of individual injection parameters on the quality of moldings was evaluated. The accordance of the results of the theoretical simulation with the real experiment was proved and a computational module independent of the optimized quality parameters, generally suitable for optimizing the quality parameters of the injected parts, was developed.
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Optimization of digital switching fields
Mikéska, Marek ; Šilhavý, Pavel (referee) ; Kapoun, Vladimír (advisor)
The diploma thesis is focused on the features description of electronics switches for digital switching arrays and on the design of program for optimal calculation of switching points and the figure of switches in digital switching arrays investigation. The electronics switches types, used for time circuit separation, are described in the preamble. These switches are the base of digital switching arrays and in principal two types are defined: the switch S and switch T. The switch S allows the interconnection only of the same channel intervals from incoming circuit with random outgoing circuit. The switch S is being used in multistage switching arrays in combination with the switches T because it can not be used separately. The switch T allows exchanging the time position of incoming circuit to different time position of outgoing circuit depending on connection needs. The time switch can substitute the space switch under specific work conditions. In practice, the time switch with controlled reading and writing is used. The following part of diploma thesis is focused on the designs and calculations of optimal switching points of digital switching array which is the executive unit of switching systems. These systems directly interconnect the signals from digital multiplexes and make the basic assumptions for telecommunication networks integration. The digital switching array means the equipment which is able to connect the channels of digital multiplexes carrying the information in encoding form. The multiplexes are the most often with pulse coded modulation or adaptive delta modulation. The digital switching arrays are divided into the time and space one. The switching arrays of digital switching systems can be made by time switching array T whose realization is limited to specific capacity or by the connection of multistage arrays. Single stages sequenced one behind each other are made by the switches T and S. The space array S does not allow making the digital switching array of switching centre. The program which determines possible proposals of switching arrays from defined figure of inputs and calculates the optimal figure of switching points and switches is a part of diploma thesis.
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Injection moulding technology of thermoplastics
Mikulík, David ; Přikryl, Radek (referee) ; Kučera, František (advisor)
The work deals with optimization of the technological mode of injection moulding of test specimens 1A of semicrystalline PP and amorphous PS. It also explores the influence of technological mode changes on the crystallinity of a semi-crystalline PP. Was set the reference technological mode for each of the polymers and subsequently changed the value of the injection temperature, mold temperature, the volume when you switch to holding pressure, injection and holding pressure. After relaxation of injection for time 24 h, and the mouldings and dogbones were weighed and thickness were measured at selected points. From the dogbones made of PP samples were taken for differential scanning calorimetry (DSC) and crystallinity was examined. From the observed weight and thickness of dogbones were determined optimal technological modes for semi-crystalline PP and amorphous PS. Examining the influence of technological change modes on the crystallinity showed no clear dependence. Furthermore, it was found that the processing of a semicrystalline PP injection moulding reduces the value of crystallinity of the polymer, compare to starting PP granulate.
|
|
|
Technology of injection molding of thermoplastic test specimens
Khamzin, Yersin ; Petruš, Josef (referee) ; Kučera, František (advisor)
The diploma thesis focuses on the optimization of technological parameters of plastic injection molding and the study of the influence of technological parameters on the quality of molded test specimens’ type 1A. The quality of molded parts for 3 types of polypropylene (PP) with different melt flow rate (Mosten GB 002, Mosten GB 218, Mosten MA 230) and 1 type of polystyrene (PS) (Krasten PS GP 154) was evaluated in terms of dimensional stability and weight. The contribution of software for modeling the plastic injection molding process was evaluated in this work. SOLIDWORKS Plastics software was used to optimize technological parameters. The construction of the bodies, mold and cooling system was constructed, and test bodies were produced on the basis of parameters obtained from the simulation of the injection molding process. Their quality parameters were compared with a 3D model and for each of the studied materials the optimal technological parameters were selected in terms of quality and the degree of influence of individual injection parameters on the quality of moldings was evaluated. The accordance of the results of the theoretical simulation with the real experiment was proved and a computational module independent of the optimized quality parameters, generally suitable for optimizing the quality parameters of the injected parts, was developed.
|
|
|
Optimization of digital switching fields
Mikéska, Marek ; Šilhavý, Pavel (referee) ; Kapoun, Vladimír (advisor)
The diploma thesis is focused on the features description of electronics switches for digital switching arrays and on the design of program for optimal calculation of switching points and the figure of switches in digital switching arrays investigation. The electronics switches types, used for time circuit separation, are described in the preamble. These switches are the base of digital switching arrays and in principal two types are defined: the switch S and switch T. The switch S allows the interconnection only of the same channel intervals from incoming circuit with random outgoing circuit. The switch S is being used in multistage switching arrays in combination with the switches T because it can not be used separately. The switch T allows exchanging the time position of incoming circuit to different time position of outgoing circuit depending on connection needs. The time switch can substitute the space switch under specific work conditions. In practice, the time switch with controlled reading and writing is used. The following part of diploma thesis is focused on the designs and calculations of optimal switching points of digital switching array which is the executive unit of switching systems. These systems directly interconnect the signals from digital multiplexes and make the basic assumptions for telecommunication networks integration. The digital switching array means the equipment which is able to connect the channels of digital multiplexes carrying the information in encoding form. The multiplexes are the most often with pulse coded modulation or adaptive delta modulation. The digital switching arrays are divided into the time and space one. The switching arrays of digital switching systems can be made by time switching array T whose realization is limited to specific capacity or by the connection of multistage arrays. Single stages sequenced one behind each other are made by the switches T and S. The space array S does not allow making the digital switching array of switching centre. The program which determines possible proposals of switching arrays from defined figure of inputs and calculates the optimal figure of switching points and switches is a part of diploma thesis.
|
|
|
Injection moulding technology of thermoplastics
Mikulík, David ; Přikryl, Radek (referee) ; Kučera, František (advisor)
The work deals with optimization of the technological mode of injection moulding of test specimens 1A of semicrystalline PP and amorphous PS. It also explores the influence of technological mode changes on the crystallinity of a semi-crystalline PP. Was set the reference technological mode for each of the polymers and subsequently changed the value of the injection temperature, mold temperature, the volume when you switch to holding pressure, injection and holding pressure. After relaxation of injection for time 24 h, and the mouldings and dogbones were weighed and thickness were measured at selected points. From the dogbones made of PP samples were taken for differential scanning calorimetry (DSC) and crystallinity was examined. From the observed weight and thickness of dogbones were determined optimal technological modes for semi-crystalline PP and amorphous PS. Examining the influence of technological change modes on the crystallinity showed no clear dependence. Furthermore, it was found that the processing of a semicrystalline PP injection moulding reduces the value of crystallinity of the polymer, compare to starting PP granulate.
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