Proposal of a new solution for mold temperature monitoring

The paper deals with the proposal of a new solution for monitoring the mold temperature. The mold is used for the production of thermosetting products by pressing technology. At present, the mold temperature is measured separately at sixteen locations of the mold. This measurement is lengthy and laborious, causing production downtime. At the same time, measurement is physically problematic since the mold has a temperature in the range of 130 to 150°C. The controller must manually record all measured data in the record and re-write the record to the computer. The new solution is to measure four control points at once. The controller will measure these points and the measured data will be sent online to the system. This method will clearly speed up the measurement process

Dynamic of taking out molding parts at injection molding

Most plastic parts used in automobile production are manufactured by injection molding. Their quality depends also on taking out molding and on the manipulators for it. Task of this contribution is to theoretically describe a transport of molding at taking out after injection molding in relation on its regulation. The following quantities are derived at it: the transition characteristic of the taking out system, the blocking diagram of taking out molding regulation, the amplitude and phase characteristic and the transition characteristic of action quantity at taking out molding regulation

Dinamička izradba odljevaka tlačnim ljevanjem

Most plastic parts used in automobile production are manufactured by injection molding. Their quality depends also on taking out molding and on the manipulators for it. Task of this contribution is to theoretically describe a transport of molding at taking out after injection molding in relation on its regulation. The following quantities are derived at it: the transition characteristic of the taking out system, the blocking diagram of taking out molding regulation, the amplitude and phase characteristic and the transition characteristic of action quantity at taking out molding regulation.Cilj ovog rada je teorijski opis transporta odljevaka od plastike poslije tlačnog ljevanja relacijom i njihovom regulacijom. Sljedeće vrijednosti su izvedene: tranzicijski karakter ustrojnog sustava, blok dijagrama izradbe regulacije odljevka, amplituda i fazna karakteristika i tranzicijska karakteristika i kvantiteta udeđaja kod ustroja ljevačke regulacije

Solving depressions formed during production of plastic molding

This 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

Evaluation of the impact energy of the samples produced by the additive manufacturing technology

The article covered the evaluation of the impact energy, notch toughness and morphology of the fracture surfaces of the specimens manufactured by the Direct Metal Laser Sintering Technology. Specimens without heat treatment with no notch were not broken through in course of testing, therefore there was no fracture surface present. The heat treatment resulted in the increase in hardness values. The values of impact energy after the heat treatment was approximately 60 % lower. Ductile intergranular fracture with more or less segmented dimple morphology appeared in every specimen. At places where the internal plastic bond was resisting the test, cracks remaining after particles broke away from the surface can be seen as craters

Stvaranje ultrafino zrnate (UFZ) strukture i mehanička svojstva sa intenzivnom plastičnom deformacijom (IPD)

Commercial pure cooper (99,9% Cu) was deformed by equal channel angular pressing (ECAP) using up to 10 passes, route C. The evolution of microstructure and fracture character were observed by OM, SEM and TEM. The mean grain size decreased with increasing deformation, after 10 passes to 100 – 300 nm. TEM analysis suggested the possible nanostructure formation mechanism by the formation of cellular structure in grains, forming of subgrains and then forming of high angle nanograins with random orientation. Fractures of ECAP Cu material after 10 passes had transcrystalline ductile character with dimple morphology.Trgovački čisti bakar (99,9%) deformiran je kanalnim kutnim prešanjem (KKP) do 10 provlaka-putanje. C. Razvitak mikrostrukture i karakter loma praćeno je sa OM, SEM i TEM. Veličina zrna se smanjuje povećanjem deformacije poslije 10 provlaka na 100-300 nm. TEM analiza ukazuje mogućnost nastajanja mehanizma nanostrukture stvaranjem celularne strukture u zrnima, nastanak subzrna i zatim obrazovanje nanozrna pod visokim kutem sa slučajnom orjentacijom. Lomovi KKP Cu materijala poslije 10 provlaka imali su transkristalni duktilni karakter sa jamičastom morfologijom

Development of Flexible Fixtures with Incomplete Locating: Connecting Rods Machining Case Study

The rapid development of manufacturing in recent years has led to a significant expansion of the technological capabilities of modern metal-cutting equipment. Therefore, the modern approach to intensifying production requires an advanced fixture design. Design and manufacture of flexible fixtures capable of machining similar shapes and sizes of complex geometry parts reduce setup time. The article aims to design flexible fixtures for parts such as one-piece connecting rods under incomplete locating conditions. The advantages are the minimum number of parts and tool availability for multi-axis machining connecting rods in one setup. This approach, combined with up-to-date machining centers and industrial robots, can increase the production efficiency of manufacturing non-removable connecting rods. This effectiveness is in a decrease in the number of operations by 5–7 times, fixtures—by 3–4 times, and machine tools—by 3–5 times, depending on the type of a non-removable connecting rod and its design features. The numerical simulation results of the proposed fixture design confirmed the comprehensive technological capabilities and dynamic characteristics. Particularly, a decrease in displacements and oscillation amplitudes up to 7% compared to the full-basing locating chart was provided. It is determined that the system “fixture–workpiece” entirely meets all the strength, accuracy, and rigidity parameters, which allows you to perform machining with intensive cutting modes. The amplitudes of oscillations do not exceed the tolerances on the dimensions of these surfaces, established by requirements for non-removable connecting rods, and all displacements are elastic. During numerical simulation, the workpiece position remained stable at all machining steps

Monitoring diagnostic indicators during operation of a print machine

This article deals with monitoring diagnostic indicators during the operation of a machine used for production of packing materials with a print. It analyses low-frequency vibrations measured in individual spherical roller bearings in eight print positions. The rollers in these positions have a different pressure based on positioning these rollers in relation to the central roller. As a result, the article also deals with a correlation of pressure and level of measured low-frequency vibrations. The speed of the print machine (the speed of a line in meters per minute) is a very important variable during its operation, this is why it is important to verify the values of vibrations in various speeds of the line, what can lead to revelation of one or more resonance areas. Moreover, it examines vibrations of the central roller drive and measurement of backlash of transmission cogs of this drive. Based on performed analyses recommendations for an operator of the machine have been conceived