Enhance Fiberboard Painting Performance Of Modified Polyurethane Paint And Technology Research

Polyurethane wood paint has been widely used into furniture, cabinets, doors and windows.Due to its structural defects of polyurethane wood paint, problems of products (such as peelingoff, nick, exposing. etc.) were often appeared when they were painted with polyurethane woodpaint which greatly affect the stability and beauty of wood products. Therefore, in order to solvesuch problems, the KH550Nano-SiO₂powders modified by surface treatment have higherstiffness, smaller particle diameter, bigger specific surface area and hydroxyls with unsaturatedand various chemical bond than traditional SiO₂powders. These properties help to increase theprobability of chemical reactions inside bonding system which have greatly improvedcomprehensive properties of paint film.The main conclusions can be described as followed:(1) The nano-SiO₂transmission electron microscopy (TEM) analysis derived of averageparticle size is about20nm, three different dispersion methods of preparing nano-SiO₂/polyurethane composite wood paint the dispersion of characterization result shows that: nano-SiO₂in polyurethane wood coatings system in the average particle size scattered around for560nm, and has certain reunion, finally choosing the most simple mechanical agitation as the finaltest of the dispersion.(2) The nano-SiO₂/polyurethane composite wood paint film structure, shape andperformance characterization of the results show that: the nano-SiO₂surface not saturated thestate and different bonding of state and polyurethane hydroxyl groups in the system of the woodpaint happens bonding reaction, makes the nano-SiO₂and polyurethane wood paint for chainbetween more strong chemical bonds has close, make system more dense, formation of nano-SiO₂/polyurethane wood paint film is of higher degree of crystallinity, glass transitiontemperature, storage modulus, crosslinking density and low surface energy.(3) Orthogonal test results show that the moisture content12.1%,180#sand paper sandmilling processing as the base material of fiberboard finishing, nano-SiO₂content is the effectof surface wet sex of the main factors, sand paper size is the second smallest, and chipboardmoisture content affect the minimum, and analyzes the factors affecting the role of wet sexmechanism.(4) Film adhesion, hardness, wear resistance properties research shows that: polyurethanewood coatings system introduced in nano-SiO₂,along with the increase of adding amount,above all properties are improved, and when the nano-SiO₂adding amount at around3%, morethan paint film the best property; along with the increase of adding amount of nano-SiO₂, paintfilm aging properties increased.(5) Painting process performance results show that the coating layer finishing fiberboardodd about3%nano-SiO₂/polyurethane composite wood coatings can greatly improve thecomprehensive performance of film, and nano-SiO₂of low cost has a very good applicationprospects.