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Konferenzveröffentlichung
Natural fiber reinforced technical (bio-) composites modified with halogen-free flame retardants
(Society of Plastics Engineers, 2019)
Under the aspect of sustainability and the use of alternative materials, engineering thermoplastics such as polybutylene terephthalate (PBT) will be reinforced with renewable raw materials such as regenerated cellulose fibers.
The University of Kassel is developing cellulose regenerated fiber reinforced technical thermoplastics in a state-funded project with further companies. Since pure natural fibers cannot withstand the high operating temperature of engineering thermoplastics (Ts>230°C), regenerated cellulose ...
Aufsatz
Effect of nanometric γ´-particles on the stress-induced martensitic transformation in ⟨001⟩-oriented Co49Ni21Ga30 shape memory alloy single crystals
(2019)
The effect of finely dispersed particles on the functional properties and morphology of thermally induced martensite in Co-Ni-Ga shape memory alloys has been already reported in literature, however, still important aspects are not fully understood. The current study focuses on the stress-induced martensitic transformation of solution-annealed, i.e. precipitate-free, and aged 〈001〉-oriented single crystals. In situ optical microscopy and neutron diffraction experiments show a significant influence of γ′-particles on ...
Aufsatz
Modification of self-reinforced composites (SRCs) via film stacking process
(2022-02-25)
This work presents the mechanical behavior of self-reinforced composites (SRCs) manufactured and modified via film stacking. For modification, interleaved films made of polypropylene (PP), a thermoplastic elastomer and a polyolefin engage were combined in different ways to induce the elastic modifier into the matrix material. The content of modifier was also varied in two ways. First, the films were produced out of a single material and second out of a compound. So, the same content of modifier was implemented in two ...
Aufsatz
Wood-Polypropylene Composites: Influence of Processing on the Particle Shape and Size in Correlation with the Mechanical Properties Using Dynamic Image Analysis
(2018-11-16)
The particle size and shape are of momentous significance for the mechanical properties of plastic composites. However, natural fillers, like wood, are not consistent in these attributes. In order to investigate the shared traits between these characteristics, WPCs were produced using polypropylene, hardwood and softwood fillers with different particle sizes and a coupling agent. Afterwards, specimens were processed using an injection molding machine. The filler sizes and shapes were measured using dynamic image ...
Aufsatz
Characterization of wood-based multi-material systems under dynamic impact stress
(2018)
Due to its naturally grown properties, wood has played a rather subordinate role as a material for technical applications up to now. In this paper, multi-material systems based on veneers of beech (Fagus sylvatica) with different reinforcing variants were investigated. In addition to the influence of different adhesive systems (urea formaldehyde and polyurethane), the effect of reinforcing by aramid fiber fabric and stainless steel foil in different climates was examined. At the center of the investigations were ...
Aufsatz
Influences on the mechanical properties of SRCs in a combined compacting and back injecting process
(2022-03-03)
In this research paper, the effects of the combined compacting and back-injection process to produce back-injected self-reinforced composites on the mechanical properties of the self-reinforced composites (SRCs) are investigated. For this purpose, the parameters barrel temperature, time of injection and holding pressure were varied for the back injection. Tensile and bending tests were carried out on the SRCs. The results show that the mechanical properties depend to a large extent on the process parameters. The ...
Aufsatz
Cross-Linked Hydrophobic Starch Granules in Blends with PLA
(2018-04-17)
The majority of native starch is used in the food sector and in the paper industry. Only a small amount is used in polymer engineering. One reason for the reluctance of the plastics processing industry to use starch as a filling material in polymer blends is the unsatisfactory mechanical behavior of starch when combined with thermoplastics. Another reason is the hydrophilicity of starch. In order to make these materials capable of competing, an amelioration of the mechanical properties is compulsory. By means of ...
Konferenzveröffentlichung
UV light irradiation of fibers in thermoplastic pultrusion for higher surface energy
(Society of Plastics Engineers, 2018)
Pultrusion is a common way to produce thermoplastic composites reinforced with different kinds of fibers. There are many different opportunities to improve the properties of a thermoplastic material. Different kind of fibers where pultruded in combination with different thermoplastic materials. The fiber content was set to 30wt% comparing the roving strain with the pultruded strain. UV-C light was used in the process to improve the fiber matrix adhesion. The pultruded strain was granulated and injection molded to ...
Aufsatz
Characterization of Anisotropic Properties of Hot Compacted Self-Reinforced Composites (SRCs) via Thermal Diffusivity Measurement
(2019-11-01)
The mechanical properties of self-reinforced composites (SRCs) produced in a hot compaction process significantly depend on the process parameters. Only a little deviation of the process temperature or pressure causes the component to act differently under mechanical load. This is a chance and a challenge at the same time, since this process is difficult to handle but by properly controlling the process parameters, the mechanical properties can be adjusted, even locally for one component. In this research SRC are ...
Aufsatz
Joining of Contact Pins and Conductive Compounds via Injection Molding – Influence of the Flow Situation on the Electrical Contact Resistance
(2020-04-09)
While a lot of research can be found in the field of bulk resistance of carbon filled polymers, comparatively few papers focus on contact resistance between compound and metal contacts. Due to that small number of researches that deal with contact resistances, studies of the influence of injection molding conditions and parameters on the contact resistance are also very rare. In contradiction to that, these influences on bulk resistance have been studied. The objective of this work was to investigate the electrical ...