Forschung

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01. Mär. 2024 | 10:09 Uhr
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Messgerät mit grünem Display und schwarzen Zahlen neben einem runden Werkstück in orange.
Comfort of Textiles is the major Factor in their Evaluation as Clothes

Reduction of Triboelectrification of Polymeric Textiles

The present work investigates the ­effect of blending polyester (PET) and polyamide (PA) by carbon fibers (CF) in the form of simple weaves and sliding on cotton textile. It was revealed that electrostatic charge (ESC) decreased with increasing CF content. besides, after sliding ESC displayed higher values than that observed after contact-separation.Weiterlesen...

28. Feb. 2024 | 08:27 Uhr
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Zwei hochkant Abbildungen mit Geräten in einer Montagehalle.
EoL Tire Recycling Methods,

Application of recovered Carbon Black (rCB) from End-of-Life (EoL) tire Pyrolysis in Butyl Rubber Compounds

In the present study „Application of recovered Carbon Black (rCB) from End-of-Life Tire pyrolysis in butyl rubber compounds“, the research on the use of rCB in new butyl compounds is presented. In general, pyrolysis of scrap tires is considered a future-oriented additional technology regarding the lack of recycling capacities. While the pyrolysis products oil and gas already find industrial application, there is still a lack of suitable applications for the solid pyrolysis residue rCB. With its reuse in butyl blends, the study investigates a potential rCB sink.Weiterlesen...

14. Feb. 2024 | 09:58 Uhr
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Sechs einzelne quadratische Abbildungen unter dem Mikroskop in grünen Farben.
Mechanical, physical, and Wear Resistant Properties of different Epoxy Composites

Enhancing the Strength and Wear Resistance of Rocca Oil based Epoxy/TiO2 NPs Matrix as Eco-Friendly Reinforcements

This study investigates the mechanical, physical, and wear-resistant properties of different epoxy composites. An ­epoxy matrix is used as the base material, while a combination of rocca natural oil and TiO2 nanoparticles is used as filler. The experiments include XRD analysis, hardness measurements, stress-strain curve analysis, friction coefficient and wear rate calculations and topography examination of worn surfaces using optical 3D and SEM imaging. The results show that the hybrid filler is well-dispersed throughout the matrix according to XRD analysis. Additionally, filling the matrix with 1.5 % TiO2 nanoparticles and 10 % rocca/epoxy matrices increases the hardness value by approximately 13.3 %. The lowest friction coefficient and wear rate were found in the sample filled with 10 % rocca oil and 1 % TiO2 nanoparticles, with reductions of 61 % and 70 %, respectively.Weiterlesen...

08. Feb. 2024 | 09:34 Uhr
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Thermografische Abbildung von vier grauen Ansichten unter dem Mikroskop.
Biodegradable and environmentally friendly Polymers made from renewable Raw Materials

Perspective Application of Biopolymers as Components of Rubber Compounds

Biodegradable and environmentally friendly polymers made from renewable raw materials are now the preferred choice for a wide range of applications. However, a combination of petroleum and bio-based sources is now being studied for developing cost-effective and environmentally friendly rubber products, with a specific pursuit of the European Green Deal. This research is focused on the application of calcium lignosulfonate into NBR rubber. The incorporation of plasticizer into the rubber compounds aimed to plasticize the biopolymer, to achieve a higher degree of homogeneity, improve the interfacial adhesion between the biopolymer and rubber matrix, and consequently achieve improved mechanical properties. The obtained results clearly show that it is possible to incorporate calcium lignosulfonate into the rubber matrix and to achieve the required characteristics of prepared vulcanizates.Weiterlesen...

05. Feb. 2024 | 10:36 Uhr
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Ggrün und graue Einzelelemte eines Dichtungsprofils.
A new type of coextrusion tool was rheologically and thermally designed

Single-Stage Profile Coextrusion of Rubber and Thermoplastics ­into recyclable Sealing Profiles

In a research project, the single-stage coextrusion of EPDM and PE-LD was ­realised. A novel coextrusion die was ­designed rheologically and thermally. During the co-extrusion trials, the die temperature and the screw speed were varied. Subsequently, the rubber was vulcanised by microwave and infrared radiation, which could easily be stopped from heating up the thermoplastic. It could be shown that coextrudates of EPDM and PE-LD can be produced in a reasonably stable extrusion process. The adhesive strength of the two layers was so high that it was not possible to carry out peeling tests. The material combination offers the possibility of reusing rejected production runs as a TPE material.Weiterlesen...

22. Dez. 2023 | 09:33 Uhr
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Figure 5: AFM images (phase image) of the 70/30 blends (e-NR/s-SBR) with 6 min mixing time (left) and 8 min mixing time (right).
from Crosslinking in Polymer Blends

Characterization of Material Inhomogeneities

The aim of the present work was the spatial characterization of potential inhomogeneities in epoxidized NR (e-NR) / solution SBR (s-SBR) rubber blends caused by crosslinking. In addition to micro-indentation and atomic force microscopy (AFM), the investigated samples were also characterized by TEM, DSC and physical testing methods. The investigated rubber blends were prepared with different polymer ratios and variations in the crosslinking system. The morphology and miscibility of the polymers were characterized as a function of the mixing parameters used. The systems are clearly two-phases, based on the polarity of the individual polymers. The investigated crosslinking systems, show a higher efficiency or solubility in the e-NR-phase.Weiterlesen...

11. Dez. 2023 | 06:46 Uhr
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FEM-Beispiel: Verformungszustände bei statischer Verpressung am zylindrischen Elastomerkörper.
Mittels Dynamisch-Mechanischer-­Analyse (DMA)

Messmethodik zur Bestimmung der Entropieverringerung deformierter FKM-Probenkörper und FEM-Software-Implemen­tierungsansatz

Mittels Dynamisch-Mechanischer-­Ana-lyse (DMA), d. h. über eine statische Versuchsführung und nichtisothermer Vorgehensweise, wird die indirekte Bestim-mung von Entropieverringerungen in Abhängigkeit des Deformationsgradienten des elastomeren Probenkörpers vorgestellt. Ein relativ einfacher, mathematischer Modellansatz erlaubt die Berechnung von Entropieverrin­gerungen aus den Messwerten. Da die Entropieverringerung sehr material­spezifisch ist, müssen für jede Elastomermischung eigene Messungen durch­geführt werden. Es wird auch andis­kutiert, wie sich die Entropieverringerung als Materialgröße in die ­Modellfunktionen von Simulationsprogrammen zur Finite Elemente Methode (FEM) implementieren lässt. Noch immer wird die Ausprägung des Gough-Joule-Effektes in deformierten Elastomerquerschnitten nur unzureichend bei Simulationsberechnungen berücksichtigt.Weiterlesen...

07. Dez. 2023 | 06:17 Uhr
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Testgerät in silber mit einem runden Testobjekt in gelb.
Concept leads to a drastic Reduction in the Number of Steps by Integrating Material

Direct Injection Molding ­Competitiveness Study

The direct injection molding concept leads to a drastic reduction in the number of steps by integrating material preparation and mixing into the injection molding process. The disadvantage of this concept is currently the insufficient miscibility of polydisperse materials in conventional injection molding machines. This study estimated the competitiveness of direct injection molding by equipping standard injection molding machine with special, so-called barrier screw with Maddock and kneading elements. Materials used for mixing are styrene-based elastomer, polypropylene and powder of calcium carbonate. ­Mixing quality was evaluated with x-ray microtomography, Shore A hardness tests and visual assessment. The study has shown that direct injection molding can be a perspective manufacturing ­approach.Weiterlesen...

04. Dez. 2023 | 10:24 Uhr
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Drei Abbildungen nebeneinander eines Stützkolben nach Nutzung.
Prüfvorrichtung optimiert und ein einheitlicher Prozess entwickelt

Messung des Kompressions­moduls von Silikon-Werkstoffen mittels eines entwickelten ­volumetrischen Kompressionsversuchs

Bei der Auslegung von Silikonbauteilen im Automotive-Bereich ist es wichtig, das mechanische Verhalten unter Zug-, Druck- oder Kombinationsbelastung vorherzusagen. In der Arbeit wird die Kompressibilität bzw. das Kompres­sionsmodul des Materials mittels eines volumetrischen Kompressionsversuchs untersucht. Dazu wird eine vorgeschlagene Prüfvorrichtung optimiert und ein einheitlicher Prozess entwickelt, um Fehler während des Versuchs zu vermeiden. Für die Arbeit werden ein Zweikomponenten-raumtemperaturvernetzender Silikonkautschuk (2K-RTV) und zwei Flüssigsilikonkautschuke (LSR) ausgewählt. Dazu wird der Einfluss von Tempern auf das Kompressionsverhalten von LSR untersucht. Außerdem wurde der Einfluss der zyklischen Belastung auf das Kompressionsmodul untersucht.Weiterlesen...

01. Dez. 2023 | 12:58 Uhr
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Kurvendiagramm mit roter  und blauer Kurve.
Behavior of Phenyl-Vinyl-­Methyl-Polysiloxane (PVMQ) Elastomers

Effect of Temperature on the Stress Softening and Damping

This study aimed to identify the effect of temperature and co-agent type on the stress softening, energy dissipation, and damping properties of phenyl-methyl-polysiloxane (PVMQ) elastomers prepared with a peroxide curing system. We identified that temperature and type of the co-agent are two critical parameters controlling the damping properties of polymers and a decrease in temperature decrease of the damping capacity of silicone elastomer. Variation of co-agent type changes the elastomer‘s cross-link density, and high cross-link densities were observed in the presence of TAIC. However, although the type and the amount of co-agents changed the mechanical properties, they did not significantly change the damping properties.Weiterlesen...