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Analýza vybraných vlastností lepených dřevěných kolíkových spojů
Linhart, Matěj
The thesis is aimed at the tensile strength of wooden dowel joint using different wood species of dowels, different types of adhesives and different material of carriers in which the dowels are glued and subsequently pulled out of them. The tensile strength of dowel joints is influenced by a several of factors which including the wood species of dowels, the type of adhesive and the material being joined. In this thesis a total of three wood species of dowels were compared (Robinia pseudoacacia L., Fagus sylvatica L., Carpinus betulus L.), two types of adhesives (PVAc adhesive Multibond SK-8 and PUR adhesive AG-PUR Standard) and two types of carrier material – insulation material Purenit and birch plywood. Both carrier materials were part of a glued spruce beam like a middle layer. A total of 12 variants of test samples were compared, which differed from each other in the wood species of dowel, adhesive type, and material of the carrier. The best results were achieved with test sample variants that contained birch plywood as a carrier and were glued with PUR adhesive AG-PUR Standard.
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Vliv teploty na pevnost lepeného spoje nábytkových hran z exotického dřeva
Maršálek, Hynek
This dissertation thesis deals with the influence of temperature on the strength of the bond on furniture parts edges from exotic wood and particleboards furniture parts for the side panels. This theme covers the furniture that is during storage and transport exposed to high temperatures. It significantly affects the strength of glued joints with hot melt adhesives. This makes it necessary to pay attention when selecting the adhesive. It must withstand not only high but also low temperatures that occur during transport furniture. The practical part is focused on the problems of thermally stressed connections between the chipboard and furniture edge from exotic wood. Samples were edged by melt adhesive based on EVA copolymers, and polyurethane-based adhesive. Test samples were subjected to cyclic thermal loading that simulated conditions of the internal environment of the transport unit. Testing was used examinations peel and oblique pressure skid. The output data from these tests were evaluated between themselves and compared with edge finished by ABS edge. As a supplementary method was also used bending test, that examined the size of the internal stress in the veneer edge
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Vliv modifikace na pevnost lepení buku
Šmíd, Pavel
This diploma thesis is focused on the influence of thermal modification on the strength of bonded joint in tension according to ČSN EN 205. For the purpose of this work was used beech wood. The thermal modification of the test samples was performed at temperatures of 160 °C, 180 °C and 200 °C. The selected bond strength adhesives were melamine-urea formaldehyde adhesives (MUF), phenol-resorcinol formaldehyde adhesives (PRF) and one-component polyurethane adhesives (PUR). In addition to the thermal modification the effect of plasma modification on bond strength is also determined. The test lamellas were plasma treated (DCSBD) prior to gluing and pressing. The result is the determination of the tensile strength of the bonded joint in all the above-mentioned modifications and comparation of the results.
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Vliv vlhkosti na pevnost lepeného spoje při olepení bočních ploch dílců koupelnového nábytku
Landová, Michaela
This thesis is focused on the effect of glue to bonding strength at DTD-L and ABS edge for increased moisture and heat interaction. This problems is concerned not only furniture, which is located in rooms with increased moisture, as are bathrooms and kitchens, but also furniture, which is exposed to these conditions in logistics during transport, storage etc. In this regard selection of right glue has a great impact on produce quality. This work is divided into two parts, theoretical and practical. There is description of methodology and formal view of problematics in the theoretical part. Experimental measurement of temperature and moisture conditions in interior and exterior are introduced in the practical part. Surface material DTD-L was used in practical part, when was tested strength of glued joints with using PUR adhesive. The samples were burden with increased moisture 90 % and 70 % and with temperatures from 25 ° C to 80 ° C. Subsequently was tested strength of gluent joints with using method of angle pressure shear angle-wise 45 ° and a peeling method angle-wise 90 °. The results were processed, analyzed and evaluated.
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