This master´s thesis deals with the complex manufacturing technology of plastic injection moulding. Literary work summarises knowledge of thermoplastic injection, thermoplastic bonding and choosing the right material for the given product. The reaction between the product and chemical substances plays a key role when choosing the right material. Therefore polypropylene is chosen for its high chemical and mechanical resistance. The given material is defined by technological data and technological process is proposed. A single-purpose injection mould for an existing injection machine is proposed for manufacturing the plastic mixing body tube corpus.

No description available.

Integrally moulded hinges and tension bands are important features in packaging components for plastic closures and their function is critically dependent on the flow induced micromorphology in the hinge section. Polymer characteristics and processing of the hinge also have an influence on the hinge properties obtained. This study is aimed at obtaining interrelationships between polymer characteristics, in-cavity flow, microstructure development and hinge properties, to produce hinges with enhanced functional properties. Three different virgin polypropylene (PP) grades were investigated (homopolymer PP-H, random copolymer PP-RC and impact copolymer PP-IC) and injection moulding simulation was carried out using Moldflow software. In-cavity data acquisition has been carried out for different sets of injection moulding conditions, using high performance transducers and a data acquisition system. A comparison between Moldflow simulation and practical injection moulding data suggests that, for thin wall injection moulded components the real time pressure data are in close agreement during the injection stage. During the packing stage there is some disagreement between these data, since the thickness of hinge and tension band sections are 0.4 mm and 0.5 mm respectively, suggesting that these dimensions are extending the capability of the software. An extensive study using a design of experiments (DoE) approach was carried out on both practical and predictive data. Injection velocity and melt temperature were the most influential factors on the component mechanical properties. From the optical micrographs it is observed that PP-RC has a finer micro-structure compared to PP-H and PP-IC and some micrographs confirm Moldflow simulation results in which hesitation effects are evident, as the flow converges into the thin hinge and tension band sections. PP-clay nanocomposites (PP-CN) were prepared using a twin screw compounder. Transmission electron microscopy (TEM) has shown some evidence of dispersion and exfoliation of the clay particles in the PP matrix. However, X-ray diffraction (XRD) results show a reduction in inter-layer spacing of PPCN s possibly due to clay compaction. The addition of nano-clay however has not resulted in any significant improvements in the mechanical properties of hinges and tension bands. The high degree of molecular orientation induced in the hinge and tension-band sections appears to mask any improvements attributed to the addition of nano-clay. From the reprocessed and post consumer recyclate (PCR) study conducted on hinges and tension bands, it is seen that with an increase in both the re-processing and PCR content there is a decrease in the component strength of around 14%, giving scope to potentially use PCR in future packaging applications. Investigations conducted on colour pigments (violet and green) reveal that the onset of crystallisation for green pigmented mouldings is considerably higher (16°C) than for natural and violet mouldings. Optical micrographs also reveal a finer microstructural texture for green components, indicating a high nucleating capability of the green pigment. Irrespective of the colour, both for hinges and tension bands, the yield stress values were around twice as high as the values quoted in the manufacturer s data sheet for isotropic PP, due to the high levels of molecular orientation in the hinge and tension band sections. In order to industrially validate the findings from the DoE study, commercial closures were produced in industry on a production tool then characterised. In the case of tension bands, there was a good agreement between the results obtained from lab scale and industrial study due to the relatively simple geometry. For hinges this agreement is not so clear. Finally a comparison of mechanical properties of the 3 PP grades shows that PP-H has a higher yield stress compared to PP-IC and PP-RC and yield stress is significantly higher (yield strain values are lower) than values quoted by the manufacturer. The PhD study has confirmed the process conditions that are able to optimise all the interactive effects to improve functional properties in high volume parts in the packaging industry.

[NO ABSTRACT PRESENT]

Emballator Växjöplast AB arbetar med att utveckla och tillverka kapsyler till världens ledande varumärken. De arbetar ständigt med utveckling och design av kapsyler för att skapa identitet, funktion och försäljning. Detta har lett till att företaget idag är Nordens största kapsyltillverkare. Dagens sortiment av 28mm barnskyddande kapsyler består av två varianter, öppen mynning eller insatspropp. De tillverkas i materialet polyoximetylen eller i polypropen i kombination med en liner. Båda materialen har god kemikalieresistans. De förslutningar detta projekt innefattar är de klassiska ”tryck och vrid”. Barnskyddande förslutningar har höga krav på sig och ska klara av kemikalieinspektionens tillsyn gällande barnskydd. Samtliga av företagets kapsyler är godkända, trots det finns ett problem på förpackningar som kommer ut till kund där barnskyddet inte är tillräckligt. Detta kan leda till reklamation hos företaget och utgör en risk att barn kan få i sig innehållet. För tre år sen ställdes ett test av Emballator Växjöplast AB, detta test har analyserats i detta projekt. Det går att konstatera att taket på kapsyler som är i direktkontakt med innehållet sväller, och därmed delvis tappar sin funktion då taket når ytterhättan. Då en liner används som barriär mellan vätskan och kapsylen sker ingen betydande svällning. Den idé vi valt att vidareutveckla är en kombination med liner, även till de kapsyler med insatspropp. Med detta sätt kommer samtliga kapsylkombinationer ha liner i sig. Utifrån de resultat vi hittills kunnat se kommer risken att kapsylerna sväller minska. Förslutningarna kommer då samtidigt bli tätare så vätska inte når gängorna, vilket gör att öppningsmomentet påverkas mindre. Även öppningsmomentet är ett problem idag då det i vissa fall är för lågt vid första öppningstillfället hos konsument. Ur det ekonomiska perspektivet ser vi att det skulle bli lönsamt att använda polypropen tillsammans med en liner till samtliga kapsyler. Denna idé skulle dessutom reducera antalet kapsyler. Användning av en liner till kapsyler i polyoximetylen är idag uteslutet för det skulle bli mycket dyrt och därför inte vara ett alternativ för kund.

The European Commission is currently working on a legislative draft to harmonise the corporate income tax provisions for multinational groups of companies throughout the European Union. For that purpose the European Commission has installed a working group with the mission to draft a Common Consolidated Corporate Tax Base (CCCTB) applicable for multinational companies. As the EU member states are not willing to surrender their taxing power to the supranational level of the EU each group entity's tax base would be determined by apportionment of the group's overall taxable income according to a predefined micro-economic factor based formula whereas the group income will be calculated by consolidating earnings beforehand separately determined by each group entity (preconsolidation income). The situs state of the particular group entity would then apply its statutory corporate tax rate on the apportioned tax base. This paper evaluates the effects of this prospective apportionment procedure on any given corporate group entity and finds that the share of the group's income allocated to a particular entity using the apportionment formula does regularly not equal the pre-consolidation income of the respective group entity. The reasons for this regular observable deviation can be found on the one hand in the concept of the apportionment formula and on the other hand in the specifics of the definitions of the apportionment factors. (author's abstract) / Series: Discussion Papers SFB International Tax Coordination

Series: WU International Taxation Research Paper Series

This thesis focuses on the generation of fine cell polymer foams using a heterogeneous nucleating agent (nanoclay), appropriate polymer blending strategies and accurate control of foam processing parameters. Foaming behaviour of HMSPP/ clay nanocomposites and HMS-PP/EVA/clay nanocomposite blends is studied using a batch and a continuous foam injection moulding system. Morphological studies using TEM and SEM led to a few interesting deductions. It is very difficult to attain complete exfoliation in case of HMS-PP/clay nanocomposites even at low clay loadings due to a non polar nature and low graft efficiencies of HMS-PP matrix. The addition of clay to an immiscible blend of HMS-PP/EVA results in compatibilization between the dispersed and the continuous phase. Nanocellular foams (290 nm) were subsequently generated in the batch process at a foaming temperature of 147oC and 25 seconds foaming time. The addition of immiscible EVA-28 to the HMS-PP matrix in presence of clay particles further results in reduction of foam cell sizes to 100 nm. The effect of gas concentration, foaming temperature, injection pressure, and foaming time on foam cell size was studied. It was found that the foam cell size was highly sensitive to the injection pressure at the mould gate (hence pressure drop rate) and foaming temperature. The cell size linearly decreased with increase in gas concentration and foaming time. The sensitivity of foam cell sizes to changes in processing parameters decreases with increase in clay concentration. The effect of addition of clay particle on gas solubility was modelled using the Guggenheims contact fraction approach and subsequently a new model to predict gas solubility was developed using statistical thermodynamic tools. Additionally the effect of shear and extensional rheology on foam cell morphology was modelled. It was found that the viscoelasticity of the polymer matrix greatly affects cell sizes as compared to extensional viscosity.

In this thesis the study of effects exogenous and engoenous factors on garlic (Allium sativum L.) plats in vitro was done. Species 'Lukan', 'Lan', 'Bjetin', 'Slavin' a 'Havran' were observed with their reactions to growth regulators added to MS medium with 0,5 mg.l-1 2iP, 0,2 mg.l-1 NAA - variants with PP 333, ABA, CEPA and increased sucrose content. During the growth of the plant, ethylene, ethane and CO2 concentrations in culturing bulbs were determined and plant growth was monitored, namely bulb creation and mass increase. At the end of the experiment, the stability of donor plant and explant was verified using DNA markers in 'Lan' and 'Lukan' species.

This paper analyzes the effects of legal uncertainty around corporate income taxation on foreign direct investment (FDI). Legal uncertainty can take many forms: double tax agreements, different types of legal systems and corruption. We test the effect of legal uncertainty on foreign direct investment with an international panel. We find that an increase in the ratio of the statutory corporate income tax rate of the destination relative to the source country exhibits a negative impact on foreign direct investment. Interacting the statutory corporate income tax rate with measures of legal uncertainty, we observe a negative effect. / Series: WU International Taxation Research Paper Series