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From the point of environmental protection, the protection of rivers, lakes, seas and oceans is very important. The general problem in the seas and oceans are the discarded plastic products, floating or sunk. Much of the plastics found the marine environment comes from industrial products, consumed or used before being thrown away with their packaging. Plastics are a big threat to the ocean environment for two main reasons. First, because of their volume – they represent 75-80% of marine litter. But also, because of their advantages: light weight – they are easily carried by currents ; and resistance to biodegradation – they build up over time. The need to reduce the quantities of discarded non-degradable plastics in the seas has led to the development of marine degradable materials that degrade completely after a certain time after having been discarded into water. The paper analyses the possibility of processing the marine degradable material using the injection moulding process, the testing of mechanical properties, and the applicability of the material for manufacturing of products that come into close contact with food.

Marine littering is one of the major ecological threats. The amount of plastic floating in oceans is increasing ; in some parts of oceans there are already 6 times more small plastic parts than plankton. Plastic floating in sea is great absorber of heavy metals, pesticides, PCBs and other toxins that accumulate in marine animals and consequently in humans. The most common sources of pollution are the ships (35 % to 85 %), i.e. people who throw various products into the sea, lost fishermen's nets, and waste from the rivers or brought by the wind. The need to reduce the quantities of plastics has led to the development of marine degradable materials, which after having been discarded into water (sea, lake, and river) degrade completely after a certain time. The paper analyzes the possibility of processing the marine degradable material using the injection moulding process, and the testing of mechanical properties has been performed.

Injection moulding is one of the most important processes of plastics and rubber compounds processing. It enables the production of very complex plastics and rubber parts, even parts made of different plastics and rubber compounds, in one cycle. The system for injection moulding of polymers consists of different elements such as the mould, injection moulding machine and device for mould temperature regulation (tempering), and additional elements: dryers, robots, etc. For successful injection moulding, optimisation of moulded part material selection as well as elements of the injection moulding system is necessary. All of the mentioned factors consume significant amounts of energy. The paper presents the analysis of energy consumption in injection moulding systems, as well as the possibilities of energy savings in injection moulding process, starting with material selection, in order to obtain a more energy effi cient process.

Injection moulding is one of the most important processes of polymer processing. It enables the production of very complex polymer parts, even with different materials, in one cycle. For successful injection moulding, injection moulding system is necessary. It consists of main elements: the mould, injection moulding machine and device for mould temperature regulation (tempering), and additional elements: dryers, robots etc. All of the mentioned elements consume significant amounts of energy. The paper presents the analysis of the possibilities of energy savings in injection moulding process, starting with moulded part geometry, in order to obtain more energy efficient process.

Modern demands on new part development and production chain are setting higher limits regarding short development and production time, as well as high level of flexibility. Tool development and production is almost always on a critical path. On the other hand, time has become the most important parameter. Rapid Tooling (RT) procedures can be one of the possible solutions. Rapid Tooling represents a series of mostly automated procedures, which enables production of the whole tools or tool elements directly from CAD data within a few hours or days. The paper represents an overview of the most important direct rapid tooling procedures.

Application of prototypes becomes more and more important in product development process. The reason lies in development of number of automatic processes of Rapid Prototyping (RP) which enables direct prototype production based on CAD model of product within few hours or days. One of the basic disadvantages of RP processes is still limited number of applicable material for prototype production. On the other hand, if there exists appropriate material for prototype production, physics of prototype production is different than of for e.g. injection moulding. This leads to key differences in properties of prototypes and future products produced by injection moulding. Such state causes application of RP processes as processes for production of elements or whole moulds - Rapid Tooling processes (RT). Different properties of materials for RT mould inserts than classic mould materials could be main disadvantage of such processes. Therefore it is necessary to analyze differences in moulding properties caused by application of RT mould inserts. In this study a prototype (hybrid) mould and a classic mould are produced. Injection moulding was performed with both moulds and properties of moulding were compared.

In today’ s production of consumers’ goods, the production of polymer products has great share and the injection moulding as one of the most significant procedures of polymer materials occupies high position on the scale of the production of goods. One of the reasons why the injection moulding is the leading processing method of polymer materials is the possibility of economical production of a great number of complex mouldings of high-quality surface. In this work, CAE tools will be used for the development of one part case for digital records’ carriers with possibility of connection with cases of the same type.

Application of prototypes becomes more and more important in product development process. The reason lies in development of number of automatic processes of Rapid Prototyping (RP) which enables direct prototype production based on CAD model of product within few hours or days. One of the basic disadvantages of RP processes is still limited number of applicable material for prototype production. On the other hand, if there exists appropriate material for prototype production, physics of prototype production is different than of for e.g. injection moulding. This leads to key differences in properties of prototypes and future products produced by injection moulding. Another trend on the market could be noticed - demands for production of larger amount of the same prototypes. In that case, RP processes are not so attractive because of the costs of prototype materials and the speed of RP process in comparison with e.g. injection moulding. Such state causes application of RP processes as processes for production of elements or whole moulds - Rapid Tooling processes (RT). Different properties of materials for RT mould inserts than traditional mould materials could be main disadvantage of such processes. Therefore it is necessary to analyse diferences in moulding properties caused by application of RT mould inserts. In this study an RT mould inserts are produced with Indirect Metal Laser Sintering process. Material for RT inserts was Laser Tool A6, and for classical inserts 1.2312. Injection moulding was performed with both inserts and properties of moulding was compared. Mouldings produced in classical mould showed higher dimensional stability as well as higher impact strength.

Injection moulding process is one of the most important processes for production of polymer medical parts. Mould for injection moulding is central and vital element of a system for injection moulding. It must be noted that 75 % of faults in the lifetime of injection moulded polymer parts (for e.g. medical plastic parts) are initiated in the process of developing, designing, and manufacturing the parts. Therefore, modern approach to mould design for injection moulding of polymers requires the application of computers and computer programs which make the mould design a significantly easier and quicker task, and provides high-quality moulds with consequently high-quality moulded parts as well.

Trend regulation of injection molding process

During the injection moulding of rubber compounds it is not always possible to achieve automatically high-quality rubber mouldings, i.e. without flash. This paper examines the effects of moulding and gate geometry on the pressure curve in the mould during injection moulding. The pressure curve in the mould cavity and in the runner system significantly influences flash appearance, it is observed that greater moulding thickness and greater dimensions of the runner system result in a lower pressure in the mould. Conversely, especially small dimensions of the point gate have as a consequence very high pressures in the mould which often cause mould opening during the injection phase, flash appearance and mould damage.

Trend Regulation of Injection Moulding Process

U radu je opisan metodički pristup konstruiranju kalupa za injekcijsko prešanje polimera. Cilj rada je dobivanje optimalne konstrukcije kalupa za injekcijsko prešanje nosača za boce koji će se kasnije plasirati na tržište. U radu su sadržani svi potrebni koraci za reološki, toplinski i mehanički proračun kalupa. Pri konstruiranju kalupa rabljen je 3D računalni program za modeliranje CATIA, računalni program Mold Adviser te standardni elementi kalupa tvrtke Meusburger.