Paint science: water-based paint, "water" use is the key!

Water-based coating has become the new favorite of the furniture industry, and water is closely relatedIts biggest feature is that water to replace the organic solvent in oily paint as a dispersive medium, compared with oily paint, do not use organic solvents, do not contain benzene, toluene, diphra, formaldehyde and other harmful substances, non-toxic non-irritating odor, saving resources is also more environmentally friendlycoatings are made up of resins, pigments, fillers, additives and solventsThe type of resin determines the type of coatingDifferent kinds of coatings, the mechanism of film formation is very differentIn order to have a principled understanding of the performance, characteristics and construction application of water-based coatings, we first need to fully understand its membrane mechanismwater-based, two-component coating film forming mechanism is different
water-based coating is mainly composed of water-based resin, face fillers, additives, water, its film-forming process and solvent-based coatinghas have a completely different mechanism, and relatively complex, mainly because of the water-based coating in the special structure and water-based resinwhen water-based single-component coatingis is applied to the surface of the furniture, the moisture begins to evaporateWith the reduction of water, the arrangement of discrete latex particles becomes more tightly arranged by evacuation, squeezed and deformed under the pressure of capillary tubes and surface tension, and latex particles fuse and diffuse into filmwater-based two-component coating in the membrane process also has the reaction of polyserocyanide and water, polyol and polyserool particles co-condensation, polyol and polyserocyanate reaction, which will affect the whole drying process of the two-component hydropolate coatingmoisture volatilization is key, but not the only factor
water volatilization, such as whether the water is in order to volatilize, whether it is completely volatile, the water-based coating film quality has a very important impactwater-based coating film can not only be a single consideration of the paint itself, but should be combined with furniture substrate type, coating method, coating equipment, drying methods and other factors to consider comprehensiveconsideration, so that the performance of water-based coating to the best, in order to make excellent surface coating effectthe membrane mechanism of water-based wood coating is more complex than solvent-based coating, the factors affecting the film are more, water is more easily absorbed by wood than solvent, water is more difficult than solvent to volatilize upward, water volatilization needs more energy than solventArguably the most uncertain factor and the most difficult process to control is the drying process!this can be seen, "water" is simply the fate of water-based paint, can be said to be also "water", defeat is also "water" So how exactly should it dry? Paint film drying methods are diverse, each method also has its own advantages and disadvantages, choose the right way to dry, seize the water-based paint door! 1 Natural drying natural drying has the advantages of simple approach and universal application but under natural conditions, temperature and humidity and wind speed are constantly changing, especially under low temperature or high humidity, drying speed is very slow, coating quality is not stable 2 Hot air drying hot air drying is the use of electric or steam heating, with a temperature of 40 to 60 degrees C, humidity 50 to 70% of the hot air as a heat carrier, through effective heat transfer for heating, thereby improving the drying speed of water-based coatings hot air drying to convection, heat conduction-based, drying room temperature has the characteristics of gradient difference, uneven temperature infrared drying 3 Infrared drying infrared drying has the characteristics of fast heating, high drying efficiency the decorated furniture plateand and its coating are irradiated in infrared light, absorb radiant energy and are converted into heat energy, thus accelerating the drying of the coating, usually using a far-infrared dry coating infrared is not suitable for drying thick coatings, and can only heat the area that infrared can be exposed to, and cannot be used to dry stereoscopic objects 4 Microwave drying microwaves are commonly used at 915-2450MHz, changing the direction of the additional electric field at a high speed of several hundred million times per second
, causing the water molecules to swing rapidly, producing significant thermal effects, thus increasing the temperature inside and outside the coating at the same time advantage is that the drying speed is fast, the coating heating is uniform, but microwave has the characteristics of selective heating, need to be selected reasonably 5 UV drying uv-cured drying methods for water-based UV coatings under ultraviolet light, the photosensitive agent in the water-based UV coating absorbs a specific wavelength of ultraviolet light, producing an active group, which triggers the polymerization reaction of the film UV drying has the characteristics of fast curing speed and good coating quality, but can only be used for drying water-based UV coatings, and only for flat furniture plate drying the ideal process of drying water-based paint is done from the inside out, the table dry inggs cannot be too fast If the wet film table dry too fast, it will greatly increase the difficulty of subsequent water evaporation, resulting in water-based paint into a bad film, and thus affect the final coating effect Water-based paint drying can take several effective combination of drying methods, taking into account many conditions at the same time make the water cleanly away! water-based coating in addition to the impact of water drying problems, there is a problem that can not be ignored, but also closely related to water, that is, water-based paint filler sprite in the crystalline water problem, and water-based paint use of filler transparent powder has different types, according to the composition classification, can be divided into sodium salt, potassium salt, calcium salt, silicon, aluminum, magnesium and so on a wide variety, different manufacturers of transparent powder, composition is not the same According to the author understand, the current market most of the transparent powder is more or less containing crystalline water, and the existence of this crystalline water will have an impact? The most direct effect of water-based coatings containing crystalline water is certainly not overclosed when detecting hot and cold shock properties Because of the presence of crystalline water, it will lead to the relative instability of the whole water-based system, affecting the transmission rate, phase, drying speed and a series of performance, potentially great product quality hidden dangers so the choice of a crystalline water transparent powder filler is also particularly important for water-based coatings source: Guangdong Qichen Editor: Shenzhen Coatings Technology Institute statement: This number of reprints, sharing, statements, views to maintain neutral, the purpose is only for industry exchanges, copyright belongs to the original author If involved in copyright and intellectual property rights and other infringement issues, please contact the background of this number, immediately delete the content processing