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Schwandorf in Bayern, Germany

Dirscherl R.,Nabaltec AG
CFI Ceramic Forum International | Year: 2010

It is now increasingly more common on a global scale to use synthetic raw materials in a variety of refractory applications. The main reasons for the popularity of these synthetic materials are their consistent chemical composition and their significantly lower impurity levels compared to the natural raw materials. A further consideration is that the natural raw materials are becoming increasingly more scarce in the world market. Higher purity materials mean predominately higher application temperatures and longer lifetimes and, as a result, the consumption and demand for synthetic mullites in fused or sintered form with or without ZrO2 (Baddeleyite) is continuously rising. Sintered zirconia-mullite is a new codeveloped and produced material by Nabaltec AG specific to the refractory industry. A comparison of the microstructures of fused and sintered stoichiometric mullites (3Al 203*2SiO2) will provide a number of underlying reasons for their development and use in specific applications. On one side the chemical, mineralogical analysis and the dilatometric behaviour are very similar. However, due to the completely different methods of producing these mullites, the macroscopic and microscopic structures are clearly different in terms of crystallinity. The ZrO2-containing stoichiometric sintered mullite is produced on purpose in an obviously variety of structure when compared to the fused materials. The different methods of microscopy (optical, SEM, BE) analysis enables an understanding of the influence of production methodology on microstructure, properties and applications. Source

El-Sabbagh A.,Clausthal University of Technology | El-Sabbagh A.,Ain Shams University | Steuernagel L.,Clausthal University of Technology | Ziegmann G.,Clausthal University of Technology | And 2 more authors.
Composites Part B: Engineering | Year: 2014

This work studies the possibility of compounding natural fibres (flax) into engineering plastics (PA6 and PB6) and comparing the results with counterpart glass fibre composites. The problem in compounding is the difficulty to compound the fibres with such polymers of high melting temperatures without decomposing the natural fibre thermally. Preliminary experiments are tried to define the possible processing window using the kneader namely temperature, compounding time and shear rate. Fibre content is tried in range of 0-50 wt.% with 10% step. The mixing temperature covers the range around the melting temperature 'Tm' [Tm-20, Tm+20] C. The use of pre-melting temperature in compounding would utilise the energy evolving by fibres mutual rubbing. Compounding time is optimised at the minimum level. Shearing rate is tried at 25, 50, 75 and 100 rpm. Optimum conditions are defined to be 210-230 C and 200-210 C for PBT and PA6 respectively. Shearing rate is also defined to lie within 25-50 rpm. Two different additives of non-organic mineral and organic phosphate flame retardants are tried with the prepared composites either alone or in combination with each other. The loading of flame retardants is limited to 20 wt.% in order to leave a space for natural fibres as well as the polymer and to keep in turn the overall composite mechanical properties. A mix of 1:1 ratio between the both types of retardants is needed to reach V0 flame retardation level. Mechanical properties are even improved 30% in E-modulus and 4% in strength with respect to composites without flame retardants. However, the injection moulding is reported to be difficult because of the high viscosity and the parameters should be optimised regarding the desired flame retardance level and the required mechanical properties as well as keeping the fibres not damaged. © 2014 Elsevier Ltd. All rights reserved. Source

Aluminium hydroxide and other functional mineral fillers are widely used in the plastics and elastomers industries. Ever increasing performance demands of compounds due to more demanding standards and new application fields lead to the need for more specialised functional fillers. One possibility to achieve higher performance of mineral filled polymer compounds is the use of special surface coated minerals to improve the interaction of the polar hydrophilic surface of the mineral and the hydro-phobic polymer. Latest results which prove the performance of specialised surface treated mineral fillers are presented in this paper. Source

Topfer O.,Nabaltec AG | Clauss M.,BASF | Schmitt E.,Clariant
Electronics Goes Green 2012+, ECG 2012 - Joint International Conference and Exhibition, Proceedings | Year: 2012

Members of PINFA, an association of producers for Phosphorous, Inorganic and Nitrogen Flame Retardants, have put joint efforts into development for engineering thermoplastics such as Polyamide or Polyesters used in connectors and switches. In this paper we will present solutions for halogen free flame retarded engineering thermoplastics compounds with a focus on efficiency of the flame retardant by a preservation of necessary mechanical or electrical performance. It can be shown that often the optimal performance can be achieved by a combination of available halogen free flame retardants. We will present results generated using various flame retardants such as Ammonium Polyphos-phate, Metal Phosphinates, Melamine Polyphosphate and Aluminium Oxide Hydroxide (Boehmite) in this paper. These flame retardants offer a powerful toolbox of possibilities which fulfill the requirements of tailor made solutions for engineering thermoplastics applications. © 2012 Fraunhofer IZM. Source

Englmann T.,Nabaltec AG | Luks A.,Nabaltec AG | Topfer O.,Nabaltec AG | Sauerwein R.,Nabaltec AG
Wire Journal International | Year: 2013

The paper discusses a new class of surface treated ATH fillers which has been developed to overcome the drawbacks of metal hydrate use in TPU compounding. Results of TPU compound evaluations are discussed in detail. This new class of metal hydrate fillers can be used at high loadings, allowing for performance and cost optimized flame retardant blend solutions in combination with organic phosphorous compounds. Source

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