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MyCol company is developing screen printable irreversible thermochromic ink for temperature indicators. Such indicators indicate heating beyond the prescribed temperature even also in otherwise inaccessible places. The labels can be produced in large quantities and are easy to handle. However, environmental influences, such as UV and visible light, abrasion, exposure to water and other chemicals, can largely reduce or even cancel the coloration. Reduced coloration and possible loss of functionality due to water is the most important factor in many applications. This work presents the effectiveness of various protective coatings applied to the thermochromic indicator layer, focusing on protection from moisture and water.

V članku je opisana analiza delovne atmosfere v lakirnici ene izmed pohištvenih proizvodenj v Sloveniji. Adsorbcija substanc iz zraka je potekala na aktivnem oglju, desorbcija pa s stresanjem v ogljikovem disulfidu. Z uporabo GC-MS metode smo v vzorcih določili prisotnost benzena, toulena, butacilena in izomer ksilena. The article describes the analysis of the working atmosphere in a varnish works of one of the furniture factory in Slovenia. The adsorbtion of air substances was carried out on activated carbon and the desorption by means of shaking in carbon disulphide. By the application of the GC-MS method, the presence of benzene, toulene, butyl acetate and xylene isomers was determined in the samples.

In this study, three-layer particleboards were produced using liquefied wood in an adhesive mixture. The influence of two different formaldehyde resins: melamine-formaldehyde and melamine-urea-formaldehyde resin and two various catalysts: ammonium sulfate and ammonium formate on the particleboard properties was investigated. There were also two pressing parameters examined: temperature and time. The following physical and mechanical properties of particleboards were measured: board thickness, density, moisture content, bending strength and modulus of elasticity, internal bonding strength, surface soundness, thickness swelling and formaldehyde content. The results showed that properties of produced particle boards were better when melamine-formaldehyde resin and ammonium formate as a catalyst were used in combination with liquefied wood in the adhesive mixture. Also, mechanical properties were improved as the press time and press temperature increased. The optimal mechanical properties of particleboards made with the utilization of the liquefied wood in the adhesive mixture were achieved at 3 min press time and 180 °C press temperature using melamine-formaldehyde resin and 3 % of ammonium formate as a catalyst. A very important characteristic is the low formaldehyde content and that is extremely important in the provision of better quality of life. With the liquefaction of wood and the application of liquefied wood in the particleboard production wood biomass exploitation could be significantly increased. We are able to produce new materials from renewable resources that can be a great alternative to the raw materials, originating from crude oil. Izdelali smo trislojne iverne plošče, kjer smo za pripravo lepila uporabili utekočinjen les. Ugotavljali smo, kako v kombinaciji z utekočinjenim lesom na lastnosti ivernih plošč vplivata dve različni formaldehidni smoli: melamin-formaldehidna in melamin-urea-formaldehidna smola, ter dva različna katalizatorja: amonijev sulfat in amonijev formiat. Ugotavljali smo tudi vpliv dveh parametrov stiskanja, in sicer temperature stiskanja in časa stiskanja. Fizikalne in mehanske lastnosti, ki smo jih ivernim ploščam določili, so bile: debelina plošče, gostota, vsebnost vlage, upogibna trdnost in modul elastičnosti, razslojna trdnost, čvrstost površine, debelinski nabrek in vsebnost prostega formaldehida. Rezultati so pokazali, da smo izboljšali lastnosti ivernih plošč, ko smo v kombinaciji z utekočinjenim lesom uporabili melamin-formaldehidno smolo in amonijev formiat kot katalizator. Ugotovili smo tudi, da so se lastnosti izdelanih ivernih plošč s časom in temperaturo stiskanja izboljšale. Optimalne lastnosti ivernih plošč, pri katerih smo lepilni mešanici dodali utekočinjen les, smo dosegli pri času stiskanja 3 min in temperaturi stiskanja 180 °C, pri uporabi melamin-formaldehidne smole in 3 % amonijevega formiata kot katalizatorja. Zelo pomembna pri izdelanih ivernih ploščah je tudi majhna vsebnost prostega formaldehida, kar močno vpliva na izboljšanje kvalitete bivanja. Z utekočinjanjem lesa in njegovo uporabo pri izdelavi ivernih plošč povečamo izrabo lesne biomase. Iz obnovljivih virov tako lahko sintetiziramo nove materiale, ki so odlična alternativa materialom, ki jih sicer pridobivamo iz surove nafte.

Wood is important natural renewable raw material that can be used for many purposes. One can say that wood and wood based products follows us from the cradle to grave. From the mid of previous century we started to massively produced and used an interesting material called wood-based panels. Wood based panels as widely used material is mostly out of wood, especially from wood residues so one can say that this industry contributes to the sustainable use of natural resources. It can be also expressed that wood-based panels are a way of recycling of wood residues. Since they are made mostly out of wood, they also store CO2. And this is not their only advantage. Second very important advantage is also its good mechanical and physical properties, which can also be altered according to their purpose of usage. Like wood, they also have good isolation properties (especially low density fibrous materials), hence contributing to lower energy consumption when used as a building material (wooden houses, prefabricated houses, passive houses, etc). One of the disadvantages of those materials is the emission of formaldehyde due to the usage of synthetic formaldehyde based adhesives. But since wood can be liquefied and later used as partial substitute for synthetic adhesives. With the usage of liquefied wood the formaldehyde emission was lowered, and since more natural material was used for the production of wood based panels they became friendlier. The aim of this paper is to show the possibilities that wood based products offer to us as a material for various purposes and as a material that can help us to reduces the use of crude oil as raw material.

Po postopku luženja z vodnim lužilom so v lesnoobdelovalnem podjetju naleteli na problem različnega nabreka posameznih letvic znotraj lepljenega elementa. Zaradi tega smo obstoječe lužilo poskušali modificirati na ta način, da bi zmanjšali njegovo penetracijo v les. Pripravili smo 15 novih formulacij, še pred tem pa smo morali razviti hitro, enostavno in zanesljivo metodo za določanje globine penetracije lužila v les. Ugotovili smo, da so štirje novi pripravki penetrirali signifikantno manj od izvornega vodnega lužila. Le-te bomo preskusili tudi v industrijskem merilu. Dobljene razlike v globini penetracije preskušenih pripravkov so izkazale, da je novo razvita metoda zanesljiva. Kljub temu pa jo bomo v naših nadaljnjih raziskavah poskušali izboljšati. Prav tako bomo proučili vpliv vlažnosti lesa pred luženjem na globino penetracije lužila. During the staining a company, producing wood furniture, encountered a problemof uneven swelling of small boards in glued elements. Therefore we tried to modify the used stain in the way that it would penetrate less into wood. We prepared 15 modified formulations of the waterborne stain, but firstly, we had to develop a simple, quick and reliable method for determination of the stain penetration into the wood. We have found that four modified waterborne stain formulations penetrated significantly less than the original one. Their performance on the industrial scale will be evaluated by further tests. The observed differences between penetration depths of the tested formulations proved that the new method is reliable. However, in order to improve the method, some further investigations will be carried out. We also intend to investigate the influence of wood moisture content on the penetration of the stain.

Wood liquefaction of black poplar (Populus nigra L.) with various polyhidric alcohols through acid catalyst method was studied for the purposes of determination the best polymer characteristics of liquefied wood, as a further raw material in modified carbamide-formaldehyde resin synthesis, with respect to adhesives in wood based panels production. For liquefaction we used several types of polyhidric alcohols (PEG, DEG, DPG, EG and glycerol) and H2SO4 as acid catalyst under defined conditions of liquefaction reaction: wood/liquefaction reagent/H2SO4 = 20.00/112.45/3.37 gram, at 150 °C for 120 min. For various liquefaction reagents mixtures of polyhidric alcohols, undissolved residue percentage (0.50-5.69%), and hydroxyl OH-number (88-567 mg KOH/g) was provide as a value which determine liquefied wood polymer characteristics. The best effects were achived using mixtures of glycerol/DEG/H2SO4 (80/20/3) and glycerol/ H2SO4 (100/3).

IGC has become powerful technique in evaluating the properties of solids and liquids. It provides access to several physico-chemical properties of such materials including their surface energy, phase transitions, crystallinity andacid-base characteristics. Kinetic parameters such as diffusion coefficients can be determined. IGC is used to characterize a wide range of product types including pharmaceuticals, natural and synthetic polymers, food ingredients and products, minerals etc.

The article describes the analysis of the working atmosphere in a varnish works of one of the furniture factory in Slovenia. The adsorbtion of air substances was carried out on activated carbon and the desorption by means of shaking in carbon disulphide. By the application of the GC-MS method, the presence of benzene, toulene, butyl acetate and xylene isomers was determined in the samples.