Adhesives are used to permanently connect the surfaces of elements made of the same or different materials. The durability of the bonded joint is influenced by the forces of adhesion and cohesion. Adhesion is the interaction of the adhesive molecules and the glued element, ensuring adequate adhesion of the adhesive to the surface of the element. Thorough cleaning of the glued elements helps to increase the adhesion forces, increasing surface roughness and mutual pressure. The adhesives are usually fluid, and their proper viscosity allows it to penetrate deep into the pores of the glued material. Cohesion is the force that acts between the molecules of the adhesive itself and keeps it cohesive.
Depending on the type of binder and form
in which it occurs, we distinguish the following adhesives.
• Zaprawy klejące – they bind as a result of reactions taking place in the binder after mixing the dry glue mixture with water – we can distinguish here cement mortars for fixing ceramic and stone tiles and gypsum mortars for fixing plaster stucco and plasterboards.
• Kleje kauczukowe – also called contact adhesives bind after evaporation of very volatile organic solvents. They are used for bonding non-porous materials and when it is difficult to evaporate and dry other types of adhesives, e.g.. for sticking ceramic tiles to metal surfaces or flexible PVC floor coverings, for floors painted with oil paint.
• Kleje dyspersyjne – they bind after evaporation of water - the binder can be acrylic resin or polyvinyl acetate. They are used to stick PVC floor coverings, carpets and wooden floors for concrete substrates, when fixing polystyrene cassettes and for sticking heavy wallpapers (lighter wallpapers are glued with methylcellulose glues).
• Kleje poliuretanowe, silicone and cyanoacrylate – One-component adhesives set under the influence of air humidity.
– kleje poliuretanowe stosowane są do przyklejania parkietu do podkładu betonowego, while offered in cartouches (assembly adhesives) they are used for quick fastening, e.g.. wooden paneling for walls
– kleje silikonowe odznaczają się bardzo dobrą przyczepnością do gładkich powierzchni np. for glass and can be used for gluing aquariums, sticking mirrors to the walls
– kleje cyjanoakrylowe zwane popularnie klejami błyskawicznymi służą do klejenia drobnych elementów z tworzyw sztucznych, can also be used for bonding metals, rubber and glass
– two-component polyurethane and silicone adhesives which bind with a hardener are very resistant to weather conditions and provide a flexible joint, so they can be used for fixing, e.g.. glass elements on facades.
• Kleje epoksydowe – two-component adhesives, they bind as a result of chemical reactions taking place after mixing the resin and hardener; They are characterized by high strength and resistance to aggressive chemical compounds – znajdują więc zastosowanie przy przyklejaniu płytek ceramicznych w garażach i na blatach kuchennych.
• Kleje topliwe – for hot glue with a special gun, used in the form of bar-shaped inserts. They are used for various assembly and renovation works, e.g.. for gluing electrical installations on walls.