| Abstract [eng] |
This master thesis is based on research of characteristics of the melamine modified urea formaldehyde resin. In literature review is overlooked the structure, characteristics and also application techniques of formaldehyde resins. There are also described processes that appeare during the bonding, also mane factors that influence the durability and longevity of the glued joints and what is more possible ways of formaldehyde resin modification by introducing a great variety of different accessories. The methodology of this work focuses on theoretically and practicaly based reviews of other researches. In order to investigate the experimental melamine modified urea formaldehyde there were organised such primary researches as the duration of resin‘s hardening, the angle of wettability, the adhesive bond‘s resistance to water and what is more the identification of the bond strength between differently mode glued wood speciments. There is also investigated the dependence of bonding strenght on the bonding temperature and the bonding time. As well there was made and establishment of adhesive bond‘s resistance to the temperature of atmosphere. Mane reserches are based on such standard as BS EN 204, BS EN 12765, BS EN 14257. Whole researche mostly focused on resistance to humidity investigation. It was found that urea formaldehyde resin‘s resistance to moisture depends on the amount of melamine that appeares in resin. The higher it is the higher bond strength is being received after some hydrothermal treatments. Taking into account all the results it must be said that products that were glued with examined resin can be used indoor, where there is a frequent but short flow of water or in spaces that are being exposed by condensation or very high air humidity. At the last part of this thesis were formulated conclusions that answer how received results enable to achieve the main target and objectives of this work. There are also given some suggestions. |
