Influence of surface modification on quality of finishing

U ovom diplomskom radu istražen je utjecaj UV zračenja na kvašenje površine bukovine vodom i vodenim lakom te adheziju i debljinu vodenog laka. Uzorci bukovine ozračeni su različitim intenzitetom zračenja u kontroliranim uvjetima s živinom lampom. Intenzitet zračenja određen je brojem prolaza ispod UV lampe pri minimalnom pomaku uzorka i maksimalnom jačinom zračenja. Kvašenje podloge ispitivano je mjerenjem kontaktnog kuta vode i vodenog premaza u određenom vremenu od aplikacije kapi na površinu. Adhezija je mjerena otkidanjem valjčića, a debljina suhog filma premaza je mjerena na mikroskopu na poprečnom presjeku uzorka. Dobivenim rezultatima došlo se do saznanja da ovisno o intezitetu zračenja uzoraka, kvašenje podloge se smanjuje, dok adhezivna čvrstoća raste, kao i debljina suhog filma premaza.In this thesis, the influence of UV radiation on the wetting of the surface of beech wood with water and water-based varnish, aswell as the adhesion and thickness of the water-based varnish, was investigated. Beechwood samples were irradiated with different radiation intensities under controlled conditions with a mercury lamp. The intensity of the radiation is determined by the number of passes under the UV lamp at the minimum movement of the sample and the maximum strength of the radiation. The wetting of the substrate was examined by measuring the contact angle of water and the water coating in a certain time from the application of a drop to the surface. Adhesion was measured by tearing off the roller, and the thickness of the dry film of the coating was measured under a microscope on the cross-section of the sample. The obtained results showed that depending on the radiation intensity of the samples, the wetting of the substrate decreases, while the adhesive strength increases, as well as the thickness of the dry film of the coating