Now showing items 1-10 of 18
Influence of the degree of crystallinity and the surface free energy on the adhesion properties of different PLA/PBS blends in multicomponent injection molding
Biocomposites made of biodegradable polymers have grown in interest due to their environmentally friendliness, considering that non-biodegradable polymers waste conduces to pollution, displaying high environmental impact in climatic changes. Therefore, in the presented study, biodegradable Poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) were investigated as a series of PLA/PBS melt-blending compounds with the weight ratios of 50/50, 60/40, 70/30, 80/20 and 90/10. In a two-component injection molding ...
Parameter identification for constitutive models of innovative textile composite materials using digital image correlation
This contribution focuses on an innovative composite material consisting of textile layers made from continuous wooden fibers embedded in a thermoplastic matrix. A finite element simulation of potential use‐cases is planned to support the development process and to study the suitability of the material in an architectural context. The simulation is based on a constitutive model assuming homogenous orthotropic elastic behavior and will be expanded to include multiscale modeling in future research. The material parameters ...
A Comparison Study of Liquid Natural Rubber (LNR) and Liquid Epoxidized Natural Rubber (LENR) as the Toughening Agent for Epoxy
Rubber-toughened epoxy resins were prepared using the mechanical stirring method and molded into samples by compression molding. The aim of this study is to modify the brittleness of the epoxy matrix by adding discrete rubbery phases to improve the toughness properties. Liquid natural rubber (LNR) and liquid epoxidized natural rubber (LENR) were used as toughening agents in the epoxy resin to compare the properties of the modified networks. The mechanical and thermal properties have been studied to observe the effect ...
Fabrication and characterization of ethylene–octene copolymer composites with ionic liquid functionalized carbon nanotubes
Modification of multi-walled carbon nanotubes (MWCNTs) by means of imidazolium ionic liquid (IL) was performed. Structural characterization of funtionalized nanofillers (IL-f-MWCNTs) was made by means of Raman spectroscopy and transmission electron microscopy. MWCNTs and IL-f-MWCNTs were introduced within ethylene octane copolymer (EOC) with octene co-monomer content of 17% by using the masterbatch approach. The efficiency of the carbonaceous nanofiller distribution within the polymer matrix was characterized by means ...
Crack path predictions in fiber reinforced composites
Composite materials exhibit beneficial features compared to conventional engineering material, e.g. a comparable strength and a reduced weight at the same time. To fully exploit these beneficial properties within technical structures, fracture mechanical concepts must be taken into account. The global fracture behavior in composite materials is related to the local delamination at interfaces between matrix and inclusion as well as the local fracture behaviors of the constituents. Because of their structure, the global ...
Investigation of residual stresses in polypropylene using hot plate welding
During the cooling process of the molten material, residual stresses appear because the reduced volume of the cooled material cannot fully fill the space formerly occupied by the molten material. The morphology in and around the weld is formed by different factors depending on the material and process parameters. Different morphological structures relate to different mechanical properties. The process parameters and the welding results including morphology and residual stress are linked together. In this article, ...
Mechanical properties of hybrid glass/kenaf fibre-reinforced epoxy composite with matrix modification using liquid epoxidised natural rubber
The hybridisation of natural fibre with glass fibre provides a method to improve the mechanical properties instead of using the natural fibres alone. This research is focused on the hybridisation of glass/kenaf fibre with the addition of liquid epoxidised natural rubber to enhance the desired mechanical properties of the composite by reducing the synthetic fibre usage and encourage the natural fibre consumption. Liquid epoxidised natural rubber was added to the epoxy matrix in order to improve its mechanical properties ...
Injection molded components with functionally graded foam structures – Procedure and essential results
In the past few years, foam injection molding has increasingly gained significance in the field of technical plastic components. This is due to the development of new processes and processing combinations and efforts to produce lightweight products. In this article, a special tool technology will be introduced, which aids the process of expanding the existing areas of applications. The technology enables the production of foam injection molded components with different foaming ratios. This is made possible by core ...
Efficient Spatial and Temporal Modelling of Material Temperatures within Self-reinforced Polypropylene Sheets during IR Radiation
Polymer composites of self-reinforced fibres and a matrix composed of the same plastic material display an outstanding mechanical performance and an excellent recyclability. Hence, these materials are suitable for many practical applications. One disadvantage, however, is the narrow processing window that is caused by a strong pressure and temperature sensitivity of the self-reinforced fibres. In this paper, an approach to efficiently model the spatial and temporal temperature evolution is presented. Advanced empirical ...