Materials Science Forum Vol. 818

Abstract: The objective of this paper concerns reducing the zinc metal content in organic coatings while preserving their high mechanical efficiency. The two goals can be achieved by using conductive polymer as components of the protective coating. Polypyrrole (PPy) was investigated as the conductive polymer. PPy was specified using physico-chemical parameters. As a binder, the epoxy ester resin was used. Organic coatings were prepared by combining zinc metal with PPy. The anticorrosive efficiency of the prepared films was evaluated using the results of direct corrosion tests.

Abstract: This work concerns the changes to wood surface morphology induced by surface cleaning with dry ice. The surface roughness values demonstrated that the surface treatment with dry ice resulted in amplified surface roughness, mainly due to the increase in the roughness of early wood. The treatment of old wood with dry ice not only guarantees effective removal of contamination from the wood surface, it also induces positive changes in other (such as wettability, surface free energy, color, and similar). This way of wood surface treatment guarantees more wood surface quality for the surface treatment, impregnation or gluing.

Abstract: The article deals with the use of sodium water glass in production of top plate of chordophones and its influence on the physical and acoustic characteristics of wood (density – ρ, modulus of elasticity – E, acoustic constant – A, speed of sound – c) as well as on the frequency spectrum. The selected characteristics of resonance spruce wood (Picea abies), were measured via non-destructive dynamic method on the apparatus called MEARFA. Measurement showed that sodium water glass influences the required characteristics (ρ, A, c) of spruce wood negatively. The frequency analysis was carried out by means of FFT (Fast Fourier Transform).

Abstract: The paper deals with the design of quantitative evaluation resulting from the decomposition products of surface-treated wood in the combustion process. This proposal evaluation in addition to monitoring the quality characteristics of the surfactant treated wood will add information on fire protection and selected environmental characteristics (emission of volatile organic compounds).

Abstract: Bacteria and mould exposures are reported to be associated with allergies, respiratory symptoms and asthma. Wood products with antimicrobial surface would reduce the risk of spreading microbial infections especially in healthcare facilities and public buildings. In future is perspective of their use.In this study, twenty five wooden composites commercially produced in Slovakia having different surfaces were tested both against moulds – microscopic fungi Aspergillus niger and Penicillium spp., and also against bacteria Escherichia coli and Staphylococcus aureus. These organisms are commonly applied as test microbes in laboratory experiments. On the basis of bacteria and mould’s growth on the surfaces of used wooden composites, the tested surfaces have been divided to three groups: (1) wooden composites with high resistant surface, (2) wooden composites with medium resistance surface, (3) and wooden composites with not resistant surface.

Abstract: The paper deals with the protection of wood in wooden building constructions, in accordance to the current trends in the use of organic materials in the construction sector and also in the woodworking industry. The attention is paid to the assessment of the effectiveness of selected retardant protective substances applied to spruce wood that was thermally loaded for prediction of flammability properties and assessing the suitability of their application. In the experiment, there was used the modified testing method with evaluation of the characteristics of thermal degradation. At the same time, there were evaluated selected material characteristics, in relation to the adhesion of retarding coatings applied.

Abstract: The paper deals with the evaluation of photostability of six selected transparent surface coatings applied on veneered furniture parts. It also estimates the influence factors such as exposure to natural sunlight in the interior, the length of exposure, wood species of used veneers and type of transparent coatings. The changing colour of surface treatment was evaluated on samples stored in the interior and being exposed to natural light behind the window glass for 6 months. Significant changes were occurred on surfaces treated with transparent coatings without UV absorber. During the first three months of exposure were arisen the most colour changes in transparent coatings of veneers.

Abstract: In this paper, adhesion of solid coatings to wood is assessed through interactions among surface forces at their phase boundary. The issue is treated on an example of beech wood and a priming UV lacquer. Our approach used analogy with the laws valid for the system solid – liquid. The results show that cohesion of wood > adhesion of coating to wood > cohesion of coating. This relation was also confirmed by the testing of mechanical loading in tension of the whole system.

Abstract: The contribution deals with the evaluation of tribological properties of materials: isothermally heat-treated cast iron ADI, heat-treated cast iron with globular graphite HTDI with sorbitic structure of the basic metal matrix and heat-treated steel C45. The aim of the research is to gain another knowledge for the application of materials in the condition where the loss of mechanical energy and the loss of material caused by parts wear are being appeared.

Abstract: The paper deals with measurement of limit strains for tinplate TS 245 made by US Steel with nominal thickness 0.3 mm. The FLC curve has been measured by implementation of Nakajima test on testing device Erichsen 145-60. The Nakajima test has been measured according to EN ISO 12004-2. Limit strains have been measured using 3D photogrammetric system Argus by GOM. Forming limit curve was evaluated in the software Argus. During test, some problems have been solved concerning friction on hemispherical punch which affected fracture position on the dome. Reached FLC curve was implemented in material database of PAM-Stamp 2G simulation software.