The aim of this diploma thesis is to ascertain the process of injecting the wax through an injection moulding machine under certain input conditions and with the help of the simulation program Cadmould 3D-F®, to perfect the injection and the following solidification of the wax. Only thanks to a perfect injection and the following solidification of the wax, a precise wax pattern can be made. In order to compare the process of injecting the wax mixture, we are helped by the Cadmould 3D-F® simulation program and the records of the injection taken by a video camera. In this thesis a simulation program used when simulating the injection of plastics was applied, as a means of comparison. In this case the similarity between the rheological characteristics of both wax and plastic was exploited.

This thesis deals with the production of a plastic body of the aperture by the method of injection moulding. The work includes a design of the injection mould for the given component. First, an appropriate material for the moulded piece was chosen and then the necessary calculations for the injection mould were made. A quadruplex injection mould with a heated inlet nozzle and pullout cores was designed based on these calculations. Modular components were chosen when designing the injection mould. The next part of the thesis contains the selection of the injection moulding machine for the given mould. The conclusion contains a technical-economical evaluation including the cost estimating for the injection mould and cost estimating for one moulded piece.

This project has been developed within the master study of Engineering Technology and Industrial Management a design of manufacturing technology for plastic cogwheel is introduced. The cogwheel will be produced by plastic injection moulding. POM material with a trade name Delrin 100 NC010 from DuPont Company will be used. An injection mould is a tool for producing a plastic cogwheel using injection moulding technology. Production will take place on the machine Allrounder 420 C Golden Edition 1000-290 from Arburg German Company headquartered in Loßburg, where the seat of parent company is situated.

This study aims to improve the design of the feeding system of industrial horizontal rubber injection moulding machines. There are many ways to implement this research. Still, the suitable design is to implement such a mechanism that will help reduce the operator intervention in the feeding system of the injection moulding machine. The FEM analysis is used to understand the real-world situation on the feed part or assembly. This analysis also provides the ability to detect the potential issues in the design, including the tension area of design and the weak spots. In the industrial horizontal rubber injection moulding machine, the same technique is used to evaluate the feeding system and based on it, the roller conveyor is designed. The 3D model is implemented using Cad software. The selection of motor for the roller conveyor and the power transmission system is also extracted to maintain the quality and enhance the feeding system's productivity. In the research, a design is presented to improve the feeding system in which the conveyor belt is designed, which provides complete support for the feeding system.

Yes / A methodical 'design of experiment' approach is used to assess the effect of key control parameters on residual wall thickness (RWT) in Gas Assisted Injection Moulding. An empirical model is produced from which the experimental RWT can be determined at any interpolated point. This model includes only those terms with proven statistical significance. The 'true' thermal boundary conditions are determined for a 1-D approximation to the system, this is sufficient to determine the error in a simulation method that enforces coolant temperature as the mould boundary condition for temperature. It is shown that errors in heat-flux and wall temperature are small. A 3-D finite element, pseudo-concentration implementation is presented, with a novel method for simulation of internal gas injection. The simulation is shown to give good agreement with the experimental rate of growth of wall thickness as gas delay is increased; good qualitative agreement is shown for other control parameters.

The gas assisted injection moulding process is an important extension to conventional injection moulding. Gas assist can be applied in a number of ways, but here the penetration of a gas bubble through the polymer melt is of interest. A 3D fi nite element implementation of a pseudo concentration method is employed to simulate the primary penetration of the gas bubble. The wall thickness prediction is an important result since the extent of bubble penetration is sensitive to the remaining melt fraction. A number of methods for experimental measurement are developed to measure characteristics of the gas assisted injection moulding process dynamics and product. Key process variables, on an industrial gas-assist machine, were measured and analysed, leading to an empirical model for wall thickness prediction. Gas delay time and injection velocity are shown to be most influential in controlling residual wall thickness. Simulation results are evaluated against the empirical model. The trends observed, for simulation and experiment, in wall thickness after changes in process variable settings are found to agree qualitatively. The wall thickness prediction is found to be within 10% of the experimentally obtained measurements. / EPSRC

No / The work presented in this paper contributes to a wider research objective aiming at gaining a better understanding of the injection moulding process at microscales. More specifically, it contributes to the development of a new modelling approach combining experimental observation and mathematical modelling to characterise thermal contact resistance that results from the imperfections present on the surfaces when two surfaces are brought in contact. Thus, this paper describes micro and nano structuring technologies (Focus Ion beam and Laser Ablation) used to structure sapphire inserts that are used as ”windows” in the injection moulding process, allowing thermal measurements with a high speed thermal camera whilst sapphire structures are filled with polymer melt. / The Engineering and Physical Sciences Research Council (EPSRC) under the grant EP/I014551/1 and the Interreg IVB project “ECOefficient LASER technology for FACTories of the future”.

The use of continuously reinforced thermoplastics have increased in recent years andoffer some significant advantages over their thermoset counterparts. The utilizationof these materials is however still limited due to the labour intensive processingand manufacturing. In the first part of this thesis, the aim is to investigate howcontinuously reinforced thermoplastics can be used in high volume manufacturingof complex components, specifically when combined with injection moulding. Thesecond part will attempt to develop a conceptual manufacturing process and designof a demonstrator part and perform a structural analysis of the component.To answer the first question, an extensive literature study on continuous fibre materialsand thermoplastics was conducted along with research on established and newlydeveloped manufacturing methods such as automated tape laying and fibre placement,tailored fibre placement and 3D printing combined with injection overmoulding. Theconceptual manufacturing process of the demonstrator part was then based on thisresearch and the design was modeled in using finite element analysis.The results shows that continuously reinforced thermoplastics can be used forhigh volume manufacturing of complex components when combined with injectionmoulding. While some of the processing methods are still in an early developmentstage, the techniques have been tested and implemented. The structural analysis of thedemonstrator part shows that the design can withstand the maximum external loadsthus and provide proof of concept. / Användningen av kontinuerligt fiberarmerade termoplaster har ökat under de senasteåren och erbjuder en del betydande fördelar jämfört med armerade härdplaster.Användningen av dessa material är dock fortfarande begränsad på grund av dearbetsintensiva bearbetnings- och tillverkningsmetoderna. I den första delen av dettaexamensarbete är syftet att undersöka hur kontinuerligt fiberarmerade termoplasterkan användas vid tillverkning med hög volym av komplexa komponenter , speciellti kombination med formsprutning. Den andra delen av arbetet kommer att försökautveckla en konceptuell tillverkningsprocess och design av en exempeldel och utföraen strukturell analys av komponenten.För att besvara den första frågan genomfördes en omfattande litteraturstudie omkontinuerliga fibermaterial och termoplaster samt om etablerade och nyutveckladetillverkningsmetoder som automatiserad tejpläggning och fiberplacering,skräddarsydd fiberplacering och 3D-skrivning kombinerat med formsprutning.Den konceptuella tillverkningsprocessen av exempeldelen baserades sedan pålitteraturstudien och designen modellerades och analyserades med finitaelementmetoden.Resultaten visar att kontinuerligt fiberarmerade termoplaster kan användas förhögvolymtillverkning av komplexa komponenter i kombination med formsprutning.Medan några av bearbetningsmetoderna fortfarande är i ett tidigt utvecklingsskede såhar teknikerna testats och implementerats. Den strukturella analysen av exempeldelenvisar att konstruktionen kan motstå de maximala belastningarna och påvisar på så sättgenomförbarhet.

The plastics industry is one of the fastest growing major industries in the world. There is an increase in the amount of plastic used for all types of products due to its light weight and ability to reprocess. For this reason, the reprocessing of thermoplastics and the usability of reprocessed materials are gaining significance, and it is important to produce and consume plastic materials in an environmentally friendly way. In addition, rising raw material cost linked to the increased oil prices encouraged for reusing of the plastic materials. The aim of this research was to study and optimize the injection moulding process parameters to achieve a trade-off between the product cost and product quality, measured through mechanical properties and geometry, based on using regrind ratios. The work was underpinned by a comprehensive study of multiple reprocessing effects in order to evaluate the effect of process parameters, material behaviour, reprocessing effects and possible links between the processing parameters and key properties. Experimental investigations were carried out, in particular, focused on the melt preparation phase to identify key process parameters and settings. Multiple reprocessing stages were carried out; using two types of PP material: unfilled and short glass filled. A series of tests were used to examine product quality (mass, colour and shrinkage) and physical properties (density, crystallinity, thermal stability, fibre length, molecular weight, in-line and off-line viscosity, tensile strength, modulus of elasticity, elongation (%) and flexural strength). This investigation showed that the mouldability of the filled and unfilled PP materials, through the successive reprocessing stages (using 100 % regrind), was observed to be relatively consistent. Given the link between the processing parameters and key product and material properties, it is possible to manufacture products with minimal loss to part quality and mechanical properties. The final phase of the work focused on process optimisation study for short glass fibre filled PP material and the identified key process parameters (melt temperature, screw rotational speed, holding pressure, holding time and injection rate). A response surface experiment was planned and carried out for three reprocessing stages (0 %, 25 % and 50 % regrind). The fitted response surface models were utilised to carry out the trade-off analysis between the operating cost (material cost, energy cost and labour cost) and product quality (dimensions and tensile strength) Based on the optimal moulding conditions, the operating cost was reduced (from stage I as a reference), by 24% and 30 % for stage II and stage III respectively. A small, perhaps undetectable, change in product dimensions was noted. In addition, a small reduction in tensile strength was noted (from stage I as a reference), by 0.4% and 0.1 % for stage II and stage III respectively. The same data was applied in other countries (Australia, USA, Brazil, Libya and China) to manufacture the same product; and it was observed that the cost was reduced with increasing of regrind ratio. But the significant reduction of the cost, essentially, depended on those countries which have low wage rates (e.g. Brazil, Libya and China). For example, the cost of moulded product manufactured in China is £ 0.025 (using 50% of regrind), while the cost of the same product produced in Australia is £ 0.12, hence giving a total saving of 79 % and making it a valuable issue to be considered in industry. / Libyan Embassy

Polylactic acid (PLA) is an aliphatic polyester, derived from sustainable natural sources that is biodegradable and can be industrially composted. This material has been in the spotlight recently due to its sustainability and properties. However it has been invented in 1932 by Carothers and then patented by DuPont in 1954 (Standau et al. 2019). The properties of this material though limit its use for applications mainly in the medical sector and in some cases single use packaging. In this research, PLA based blends with improved rheological and thermomechanical properties are investigated. The focus is based in proposing strategies in improving these properties based on commercial methods and processing techniques. In this work, commercial grade PLA has been blended with polycaprolactone (PCL) and polybutylene succinate (PBS) in binary and ternary formulations via twin screw extrusion. PCL has been known to act as an impact modifier for PLA, but to cause a corresponding reduction in strength. Results showed that the binary PLA blends containing PBS and PCL, had reduced viscosity, elastic modulus and strength, but increased strain at break and impact strength. Morphological and thermal analysis showed that the immiscibility of these additives with PLA caused these modifications. Incorporation of a small loading of PBS had a synergistic effect on the PLA-PCL blend properties. Miscibility was improved and enhanced mechanical properties were observed for a ternary blend containing 5wt% of both PBS and PCL compared to binary blends containing 10% of each additive. To increase heat resistance of PLA, the material’s crystallinity has to be increased. However PLA has a relatively slow crystallisation rate making it difficult and expensive to be used in commercial applications where heat resistance is needed. For this reason the chiral nature of PLA has been used to investigate the effect of stereochemistry of PLA in crystallisation. Optically pure PDLA was added to its enantiomer in small amounts (up to 15%) and the properties and crystallisation mechanism of these blends was investigated. Results showed that the addition of PDLA accelerated crystallinity and developed a stucture that increased heat resistance, melt strength and stiffness. Finally, a processing model of developing a fully stereocomplex PLA part based in commercial techniques is proposed. Injection moulded PLA showed even higher heat resistance without the need of further processing the product (increasing crystallinity). / Floreon