The objective of this study is a comparison of different compounding techniques and their influence on Young's modulus. Both conventional processing of polymer nanocomposites and processing in the unique Injection Moulding Compounder (PNC-IMC) were evaluated. Additionally, the effects of nanofillers on the thermal conductivity of polymer nanocomposites were investigated at various pressures.In comparison to conventional compounding process, in which the compound must be pelletized and fed into the injection moulding machine for the second plasticizing process, injection-moulding compounding combines these two processing steps. The material compounding and the subsequent injection moulding are done directly with only one plasticizing process, with the use of a heated melt line and a melt accumulator. In this study, both of these techniques were used for the production of polymer nanocomposites. This paper shows the different effects of processing techniques, screw speed, counter-pressure and different extruder length on Young's modulus and demonstrates that, for the improvements, a compromise between shear energy input and residence time is essential. The increase of thermal conductivity by using nanofillers in comparison to the virgin polypropylene is shown. The investigated increase in thermal conductivity should be extremely appealing for the industry in terms of cycle time reduction in the injection moulding process.These first results give an excellent overview of both the possibilities and the limitations of the innovative concept of the PNC-IMC. Further studies on the detailed understanding of the exfoliation and intercalation of layered silicates in polymer melt will be done.
In the present investigation, polypropylene clay nanocomposites (PP-CNs) are prepared by melt compounding using the Polymer NanoComposite Injection Molding Compounder (PNC-IMC) with different nanoclays and at varying compatibilizer/nanoclay ratios. A specially devised hyperbolical nozzle is used to induce elongational flow for better mechanical properties. Statistical analysis of the mechanical properties reveal that PP-CNs based on mica-phlogopite is superior to other PP-CNs. Beside intercalated and exfoliated structures the SAXS results confirms that the PP-CNs show well aligned and also randomly disordered structures. TGA shows among the investigated nanoclays organic modified montmorillonite (OMMT) shows substantial improvement in thermal stability of PP-CNs.
Front Cover: Polypropylene clay nanocomposites (PP‐CNs) are produced using a polymer nanocomposite injection molding compounder (PNCIMC). This article explores a new trend in processing of PP‐CNs with the use of a hyperbolically shaped nozzle which induces an elongational fl ow for better material properties. With the use of various organoclays and different clay contents the improvement of mechanical properties and thermal stability are presented. With the use of PNC‐IMC the production of polymer clay nanocomposites is shown to reduce energy and time. Further details can be found in the article by S. Arunachalam, M. G. Battisti, C. T. Vijayakumar, and W. Friesenbichler http://doi.wiley.com/10.1002/mame.201500107.
This study is concerned with the flow behaviour of a rubber compound in capillary and injection moulding dies in the temperature range of 80-120°C. The injection moulding die designs had a tapered angle ranging from 40°up to 150°. The rheological characterisation of the rubber compound in the capillary dies showed that rubber slips at the wall, and this was modelled with an appropriate slip law. The pressure drops in the system were measured for all tapered dies. Numerical simulations were then carried out with a purely viscous (Carreau) model and a multimode viscoelastic (K-BKZ) model. The results showed a good agreement with the experiments for both the capillary and the injection moulding dies, provided that slip is included in the simulations as determined experimentally.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.