Uticaj sistema brušenja Paulownia siebold et zucc. na sposobnost kvašenja

Abstract

U ovom radu ispitivan je uticaj pripreme površine podloge na sposobnost kvašenja poliuretanskih lakova metodom kontaktnog ugla. Uzorci su izrađeni od dve vrste paulovnije (Paulownia elongata i Paulownia fortunei). Svi uzorci su obrađeni rendisanjem (glodanjem), posle čega je vršena obrada brušenjem pri čemu su uzorci podeljeni u grupe. Za svaku grupu u odnosu na pravac drvnih vlakana, određen je sistem obrade brušenjem, zasnovan na numeraciji brusnog papira, redosledu smenjivanja brusnih traka različite numeracije i pravcu brušenja. Kvalitet pripreme podloge posle brušenja izražen je preko parametara hrapavosti u sistemu 'M': Ra, Rz, Rv, Rp i Rt. Za merenje kontaktnog ugla korišćen je transparentni poliuretanski (PU) lak i destilovana voda. Vrednosti kontaknog ugla dovedene su u vezu sa sistemom brušenja preko parametra hrapavosti Ra.

This paper presents the research of influence of wood surface preparation on the wetting ability of polyurethane coatings, by the method of contact angle. The samples were made of two species of Paulownia (Paulownia elongata and Paulownia fortunei). All the samples were processed by planing (molding). After molding, the samples were arranged in groups and sanded. In relation with wood grain direction, each group had a particular system of sanding, based on the numbering of sanding paper, program of displacement of sanding papers with different numbering and the direction of sanding. The quality of wood surface after sanding was expressed by the values of roughness parameters in the system 'M': Ra, Rz, Rv, Rp and Rt. The contact angle was measured using transparent polyurethane (PU) coating and distilled water. The influence of the system of sanding on the values of contact angle was analyzed by roughness parameter Ra.