Fungus and fire resistance of insulation mats based on water glass bonded non-textile flax fibres
Materials and methods Field retted flax crop were processed to fine non-textile fibres as specified elsewhere (Grohe 2003) and the material employed for the manufacturing of insulation mats. Water glass was applied as an adhesive and a solution prepared by adding 50 vol.% water to the received viscous water glass (Betol 39T1, 36 wt.% solids in water, Woellner Silikat GmbH, Ludwigshafen, Germany;) leading to 18 wt.% solids in water (pH 11). An aqueous borate solution of 14 wt.% boric acid and 10 wt.% sodium hydroxide (33 wt.% NaOH solution) was mixed, giving 24 wt.% solids in water (ph 13). Thus, the mixture contains a fraction of 21.6 wt.% of the flame retardant and fungicide Borax (Na2B4O7·10 H2O). The B(OH)3-solids and the NaOH-solution were received as technical grade by Zschimmer und Schwarz, Lahnstein, Germany. Insulation mats were fabricated via a pilot plant, as described by Grohe 2003. During the process flax fleeces were sprayed either with (A) water glass or with (B) water glass and subsequently with the boric compound. Some insulation mats were fabricated by primarily spraying them with (C) boron-solution followed by another cycle comprised the spraying of water glass and boric compound. Test-series were carried out (Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany) to investigate the biological resistance of insulation mats fabricated via the production runs (A), (B) and (C) (see Table 1). Thereby, five samples (90 · 90 · 40–55 mm) of each production run were exposed to pure cultures of the wood destroying fungal species Aspergillus niger, Aspergillus terreus, Aureobasidium pullulans, Paecilornyces variotii, Penicillium funiculosum, Penicillium ochro-chloron, Scopulariopsis brevicaulis and Trichoderma viride and the degree of fungal attack verified, according to DIN IEC 68-2-10. To investigate the fire properties of insulation mats five samples of the series (B) were tested according to DIN 4102-1 (FIW—München, München, Germany).
Heat conductivities of insulation mats based on water glass bonded non-textile hemp or flax fibres
Heat insulation mats based on water glass bonded non-textile flax and hemp fibres were fabricated via a pilot plant, and their heat conductivities investigated. Under the influence of various factors like moisture content, water sorption and diffusion processes, fibre characteristics and heat radiation as well as thickness and apparent density, heat conductivities in the range of 0.0392–0.0484 W/mK for flax fibre mats and 0.0441–0.0592 W/mK for hemp fibre mats were obtained. Strong interactions between the fibre characteristics on the one hand and the water sorption and diffusion processes, the heat radiation, the apparent density and the thickness on the other hand were found. Investigations of tensile strengths and dimension stabilities indicate that the isolation mats are easy to handle and a structural alteration of an overall construction will not occur.ZusammenfassungWärme-Dämmstoffmatten, basierend auf wasserglasgebundenen, nichttextilen Flachs- und Hanffasern, wurden über eine Technikumanlage hergestellt und deren Wärmeleitfähigkeiten untersucht. Unter dem Einfluss verschiedener Faktoren wie Feuchtegehalt, Wassersorptions- und Diffusionsprozesse, Fasereigenschaften und Wärmestrahlung sowie Dicke und Rohdichte wurden Wärmeleitfähigkeiten im Bereich von 0.0392–0.0484 W/mK für Flachsfasermatten und 0.0441–0.0592 W/mK für Hanffasermatten erhalten. Es wurden starke Wechselwirkungen zwischen den Fasereigenschaften auf der einen Seite und den Wassersorptions- und Diffusionsprozessen, der Wärmestrahlung, der Rohdichte und der Dicke andererseits gefunden. Untersuchungen der Zugfestigkeit und Formbeständigkeit zeigen, dass die Isolationsmatten einfach zu handhaben sind und eine bauliche Veränderung einer Gesamtkonstruktion nicht auftreten wird.
Accurate measurements of output characteristics and detonations of motorbike high-speed racing engine and their optimization at actual atmospheric conditions and combusted mixture composition
Abstract At a motorbike high speed racing engine there is very important an output engine characteristics which depends significantly on a detonation combustion rate, atmospheric conditions and a combusted mixture composition. The combustion process has got a relevant influence on a wear degree of main engine parts or on their damage eventually. The detonation combustion rate is very important because this kind of burning can be not only destructive but a useful phenomenon, as well. If the process of detonation burning is kept on a certain level, it can help significantly to the next increasing of an engine power output. In this article there is described the measurements of output characteristics of a high-speed racing engine which were performed by means of a data-recording system and the detonation combustion was evaluated using a quantitative method. The actual values of atmospheric conditions and the mixture composition were added to the measured values. Then the obtained values are compared visually with a damage degree of an engine piston caused by the detonation burning. The result is a limit value expressed in a number of detonation units related to a run distance interval of the vehicle driven by the high-speed racing engine. In framework of this run distance interval there is the process of detonation burning profitable. As well as it increases an engine power output and together it is not destructive with regard to engine design parts.