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Heat resistance of wood bondlines
Šustáček, Jan ; Melichar, Tomáš (referee) ; Vaněrek, Jan (advisor)
This thesis is focused on studying the impact of elevated temperatures on the resistance of bonded joints. The aim of this study is to assess the impact of exposure to temperatures on selected types of adhesives. In the theoretical part was made research and comparison of selected species agglomerated materials and described the issue of fire safety of buildings. To determine the strength characteristics of bonded joints at different temperatures have been made in the practical part load tests according to valid standards.
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Utilization of accelerated durability test of wood glued joints for consequent service-life prediction
Šmíra, David ; Tupý, Michael (referee) ; Vaněrek, Jan (advisor)
The aim of my diploma thesis are methods which are able to describe durability aspects of glued wooden joints. The main objective are methods which primarily includes hygrothermal stress acting in the glued joint of wooden adherend and determine the service life of the specific glued joint by modelling based on Arrhenius relation and the other methods. Other part of this work is aimed to shear tests of the samples exposed to different thermal and humidity conditions and for individual sets of exposures determining the glue penetration depth into the wooden adherend by EPI fluorescent analysis. These analytic methods are used for quality check of the glued joints, which are mostly based on strength, chemical or structural parameters of the tested sample.
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Adhesion of Adhesive Joints for Facade Applications Made of Wood-based Materials
Nečasová, Barbora ; Schmid, Pavel (referee) ; Sedlák,, Petr (referee) ; Kovářová, Barbora (advisor)
The presented dissertation thesis is focused on investigating the adhesive properties of façade cladding made of wood and wood-based materials in combination with flexible adhesion/assembly systems. The systems allow the implementation of effective construction joints and provide a solution with uniform stress distribution which allows the transfer of heavy loads, while simultaneously reducing the weight of the entire structure, which is also often connected with substantial cost reductions. Despite all that, little attention has been paid to this area so far. It is not a solution which is properly embodied in technical standards or in designers´, architects´ and contractors´ awarenesses. The aim of this dissertation is to characterise adhesive properties of selected façade cladding representatives made of wood and wood-based materials for the purposes of bonded joint application in a ventilated façade system. To define adhesion of façade joints, numerical and experimental methods are used, taking also various limit conditions into account. The main conclusion of the dissertation is the characterisation of basic parameters which influence adhesion, effectiveness and quality of façade glued joints. The secondary conclusion is the compilation of a simple methodical procedure for testing and implementing façade glued joints. The dissertation also makes a contribution by extending the current state of knowledge of façade adhesive joints.
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The study of adhesion of glued balistic composites on the dependence of materials used.
Dobiáš, Jiří ; Másilko, Jiří (referee) ; Šiler, Pavel (advisor)
The aim of this work was to investigate the properties of bonded ballistic materialsBalistic composites are mainly glued to reduce weight while keeping their protective properties. On this basis, the materials used were ballistic steel, ceramics, rubber kevlar, non-gummed kevlar, Dyneema and fiberglass. For bonding used were a one-component adhesive Collano 36.104 and two-component adhesive Biresin U1305. The strength of the joint was measured in shear at tensile loads. From these results, deformation energy was further calculated.
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Repair of surface sliding
Teplý, Miroslav ; Vyplašil, Evžen (referee) ; Kubíček, Jaroslav (advisor)
The selection of suitable materials for the renovation of sliding shafts requires a comparison of several criteria. The main criteria were selected size shear strength under tensile stress lap bonded assemblies, resistance to adhesive wear and economic criteria. From the results of all tests is selected the most suitable friction material to repair worn out places of shaft. The technological process of sealing the shaft was drawn up on the basis of the literature, recommendations supplier of sliding materials and their own experience.
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A comparison of different types of epoxy adhesives
Mihulka, Jan ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
This thesis is focused on a bonding technology. The first part describes the theory of the bonding and it is discussed the main areas of this technology. The experimental part deals with the comparison of four two-component epoxy adhesives in terms of shear strength. For the experiment it had been selected adhesives: Bison Epoxy Universal, Pattex Repair Epoxy Ultra Strong 5 min, Ergo 7430 and Letoxit LH 232. After performing the experiment, it was shown that Bison Epoxy Universal and Pattex Repair Epoxy Ultra Strong 5 min achieved the strengths stated in the datasheet. The strengths of Ergo 7430 and Letoxit LH 232 adhesives was lower than stated in their technological products, thefore, did not meet our expectations. The reason for not achieving the declared strength was probably poor dosing or insufficient mixing of ingredients.
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Repair of machinery
Teplý, Miroslav ; Kovář, Petr (referee) ; Kubíček, Jaroslav (advisor)
Theme of this Bachelor´s thesis deal with problems of repair of machinery - repair the shaft. The thesis is divided into two parts. The first part deals with the possibility of using thermal spraying for the renovation of the shaft surface at the point of contact with the shaft seal ring. The second part deals with the use of epoxy putty for the renovation of the shaft surface at the imposition of a bearing.
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Vliv teploty lepidla a povrchu adherendu na hloubku penetrace lepidla do masivního dřeva
Voldřichová, Anna
The final thesis deals with the influence of different gluing conditions on the depth of penetration of the adhesive into the surface of solid wood, specifically of the influence of increased pressure during pressing. Furthermore, the thesis investigates the effect of penetration on the strength of the glued joint under tensile loading. Specimens of spruce and oak wood were glued with UF glue and PVAC glue, pressed under different compression pressures and then subjected to tensile test. SEM analysis on an electron microscope was used to evaluate the depth of penetration. The results of the investigation of the effect of ink on the strength of the bonded joint and the penetration depth of the adhesive into the material are also included. The ink was used in the adhesive mixtures for the purpose of colouring the bonded joint.
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