Reasonable application method of water-based wood coatings in painting

1. Water-based wood coating application area
the main film-forming substances of water-based wood coatings are water-based resins, wood coatings commonly used resin types by chemical structure classification mainly acrylic, polyurethane, acrylic-polyurethane and water-based alcoholic acid and other major categories. Moreover, the film-forming film of water-based wood coating is an irreversible process of non-versal and non-molecular level, which has experienced the stage of accumulation, compression and fusion of latex particles. In order to form a high-quality coating film, often need to rely on film-forming additives, relatively poor

. And water-based wood coating film-forming material hydro-hydro, so coating film in water resistance, chemical resistance and other properties to be relatively poor solvent-based coatings. The above types of water-based wood coatings are mainly single-part, in order to solve the above-mentioned single-part water-based wood coating defects, water-based two-part wood coatings and water-based UV coatings in recent years have also developed rapidly and have been widely used. The advantages of water-based wood coatings are simple construction, small odor, good adhesion, good leveling, the disadvantage is that the drying speed is relatively slow, hardness and chemical resistance in general. Therefore, water-based wood coatings can be applied to wood coatings that do not require high hardness and do not come into contact with highly corrosive solvents. In industrial coating to meet the above characteristics of wood products are mainly children's toys, suite furniture, wooden dining chairs, wooden window frames, indoor wooden doors and wooden floors.
2. Coating effect and coating process design
a wide variety of wood products materials, from wood grain, with deep catheters (e.g. water willow, oak, etc.) and shallow catheters (e.g. birch, red cherries, etc.); Hard parts, there are cork (e.g. red pine, birch, birch, etc.) and hardwood (e.g. old birch, pear wood, birch, etc.); Water-based wood coatings in factory coating applications need to choose the appropriate coating effect and coating process according to the type of wood material and the use of wood products painted.
children's toys, China
a global toy manufacturing country, about 70% of the international toy market sales provided by China. Wood children's toys with bright colors and imaginative shapes to attract consumers, so the material needs good mechanical processing; Density plate cheap, good mechanical processing, no natural wood texture, the most suitable coating effect is solid paint, generally using two-sided process; Coating methods can be applied, brushed, rolled and impregned. It is important to note that there are many adhesives in the density plate, and the raw materials used are more cluttered, the construction of water-based primers is very important. When coating, you need to choose a water-like primer with closed tingate and grease properties to prevent the coating from changing color. Wood children's toys from the finished film performance requirements are not high, the need to strictly control the main content of harmful substances in the coating film, including heavy metals, polycyclic aromatic hydrocarbons, glycol ether and its esters, benzene and free formaldehyde. Toys film odor is small; in chemical resistance, only need to meet a certain amount of water, alcohol and other daily chemicals and coffee, green tea and other drinks can be; wood children's toys on the film hardness also does not need high requirements, but need better flexibility, cracking and temperature change; paint on wood adhesion is better, the corner of the toy can not drop paint; In many years of practical application, water-based wood coating for children's toys above the performance requirements can be well met.
wooden dining chair
from the practical application, the dining chair is mainly in the indoor for people to eat, leisure time to lean on and ride the apper equipment. In the process of moving or moving the position will appear bumps, as well as the use of coffee or tea sprinkled on the above problems, so the finished wooden dining chair on the coating requirements have good adhesion, excellent resistance to tea, coffee, red wine and cola staining performance, good anti-adhesion performance. The daily output of wooden dining chair manufacturers is larger, generally medium-sized dining chair manufacturers nissan more than 1,000, requiring manufacturers to have high production efficiency, so wood dining chair manufacturers mostly use assembly line coating operations. The pipeline has a heating and drying system, so the water-based wood coating drying slow defects can be made up. Wood dining chair wood for birch, birch, water willow, maple wood and other solid wood, the use of coating effect to open and semi-open mainly, but also can be divided into varnish and solid paint, varnish can do the color (do not do any color effect) coating effect, can also do transparent color coating effect, transparent color effect generally use the bottom coloring process color; The typical coating process is roughly as follows: the use of two bottoms on one side or two sides, each spray 1 to 2 guns, each coating film spray first at room temperature drying about 10 min, coating film table drying into the baking system for forced drying (general temperature control at 30 to 40 degrees C) about 1 h, out to cool 10 min after grinding dust removal, and then into the next process. After coating the wooden dining chair film feel smooth and delicate, varnish transparency, clear wood grain, natural color, solid paint cover strong, do not lose color.
Indoor wooden door
interior decoration is the most expressive factors of the choice and matching of decorative wooden doors is the whole home decoration process of the "painting dragon's eye" pen, wooden doors are more and more favored by decoration owners. Indoor wooden door in the coating performance generally requires the odor as small as possible, good flexibility and adhesion, coating film feel good, with a certain water-resistant wipe performance; Chemical coating is mass production, spraying, first spray door of a plane, to be about 5 to 10 min after spraying another plane, and then hanging drying, so the paint required to level good, dry fast, anti-flow hanging. There are many kinds of materials in indoor wooden doors, water-based wood coating in indoor wood door coating applications, according to the type of material reasonable selection of coating process is particularly important. (1) Wood with deep wood grains such as water-curly willows and oaks generally has a fully open coating effect, because the solid content of water-based wood coating is relatively low and the plumpness is relatively poor. If the use of a fully enclosed coating effect, spraying times will require PU (polyurethane) paint twice or more to achieve satisfactory coating fullness, and the water-based coating itself drying speed is much slower than PU coating, so that the factory production of a set of doors takes 7 d or more time, greatly reducing plant productivity. Using the open effect, the typical coating process is roughly two sides, each time only need to spray 2 to 3 guns can be, greatly shorten the drying speed, improve production efficiency. (2) like red cherries, maple wood and other wood lighter wood, can use a fully closed effect, the typical process is roughly three-bottomed side, each time need to spray 4 to 5 guns;
wooden suite furniture
wood suite furniture mainly refers to wardrobe cabinets, beds and bedside table, especially now children's suite furniture, water-based wood coating applications accounted for a large proportion. Suite furniture has been in direct contact with us for the longest time, and the size of its odor and the amount of harmful substances directly affect our lives and health. Although solvent-based coatings are better than water-based wood coatings in terms of performance, with people's concern for health, green water-based wood coatings have been developed rapidly. In the coating performance, suite furniture requires good adhesion, a certain amount of water-resistant wipe, good impact resistance, delicate feel and better transparency; Wood suite furniture materials are also the same as indoor wooden doors as a wide variety: like water willow, oak and other wood-printed wood, generally using a full open coating effect, typical process for two sides;
wooden floors
with the improvement of people's living standards, the previously cold tiles are now increasingly replaced by wooden floors to decorate the floor and even wall panels. Especially in the bedroom, study and living room floor, more people like to use wooden floors to lay. Wood floor feet feel comfortable, especially suitable for the elderly and children living, very suitable for the human body, especially can make people feel the natural warm home environment. The most important requirement for coating performance of the floor is wear resistance and scratch resistance, followed by resistance to daily chemicals. From the performance point of view, the general single-group water-based wood coating is more difficult to meet the requirements, especially the water-based acrylic system, wear resistance is more difficult to meet the standards. In wear resistance has a certain advantage is the water-based PUD resin, its wear resistance is even better than solvent-based PU coatings, but in the plumpness and water resistance slightly lacking. Therefore, wood flooring water-based wood coating system is generally selected is water-based two-part system or water-based UV system, the water-based two-part system is referred to here is with polycyanate to react with the product, through the water-based resin A-part containing - OH and containing polyocyanate polymer water dispersable body of the B-group mixed to produce a dense coating film, belongs to the cross-linked reaction products. This type of water-based wood coating is also the performance closest to solvent-based coating performance of a class of products, its wear resistance is better than solvent-based PU, and UV-cured water-based wood coating and traditional UV-cured coating ratio can be said to have obvious advantages, the outstanding advantage is that VOC can tend to zero, no active thinner Easy to adjust viscosity, not only reduce the odor of active thinners and irritation to the human body, but also can obtain a high hardness and flexibility of the coating film, its hardness is slightly worse than traditional UV coatings, but wear resistance, scratch resistance, chemical resistance and cup burst experimental results can be better than traditional UV coatings. The disadvantage is that the need to increase infrared drying performance before entering the UV machine for water flash drying, but only a device investment, other coating lines can also be used, not a waste. From the material, wood flooring material types to solid wood (including density board solid wood skin) as the main, the shape of the rules of the rectangular flat plate, so the floor factory production is supplemented by infrared dry roller coating production line, UV cured water-based wood coating is also supplemented by UV machine drying. The typical coating process of water-based two-part floor coating is two-bottomed one side, while UV-cured water-based wood coating is more than three-bottomed one side.
wooden cabinets,
with the rapid development of home decoration industry, the overall cabinet is very popular. The overall cabinet can be in accordance with the consumer's home kitchen structure, area, as well as the personalized needs of family members, through the overall configuration, overall design, overall construction, and finally form a complete set of products; And in order to have more personalized and visual enjoyment, more people to wooden cabinet board as the first choice. From the coating performance point of view, cabinet paint needs to have excellent alcohol resistance, vinegar, red wine and cleaning brush, but also need to have good adhesion; Now the overall cabinet is mostly in the factory separate coating, to the owner's home and then put together, so the shape is also as many as wooden flooring for flat panels, easy to spray. Because the actual application of cabinets, the general single-group water-based wood coating is difficult to meet its high chemical resistance, so, cabinet water-based wood coating for water-based two-part system or water-based UV system, because of the need for personalization, plate has a simple shape, suitable for spray construction, not suitable for roller coating construction. Water-based two-part cabinet plate coating typical coating process for two-bottom one side, UV-cured water-based cabinet plate coating is more than three-bottom one side.
wood window frame
water-based paint for outdoor window frames, has been abroad for forty or fifty years, there are cases to maintain the integrity of window frames and protection performance for more than 28 years without maintenance. In China, water-based coatings for wood window frame coating also has more than 20 years of application cases. Wood window frame on the requirements of the paint is mainly good adhesion, rain resistance, flexibility, with a certain degree of adhesion, hardness without special requirements. The use of nuclear-shell structure of water-based resins, and the addition of ultraviolet absorbents, bit-resistance amines and film preservatives made of water-based wood coating, with excellent aging resistance, flexibility, water-resistant mold resistance and excellent adhesion, and has a certain degree of abundance, as a wood window frame paint, has a very high applicability. Wood window frames are mainly made of pine, birch and birch, and the coating process is relatively simple. Pine catheter shallow, generally do transparent color full closure effect, the typical coating process is as follows: immersion primer (coloring) → transparent finish (1 to 2 times) → transparent colored paint;
American antique wood furniture
American antique coating is the United States popular antique furniture coating method short, through the paint and construction methods to process furniture, so that it has the characteristics of "antique", that is, artificial old. American coating is mainly nitro coating, because of its fast drying, low solid content, high transparency of coating. With the improvement of environmental standards and the continued high prices of raw materials, more and more factories are now using water-based wood coating system for the coating of American antique furniture. The most important color system in antique coatings is the color system, including material finish, Glaze coloring, bottom finish, cloth printing coloring and oxtail dry brush, etc., correspondingly supporting transparent primers and transparent finishes. Antique furniture to be "antique" special effects, coatings play only a simple protective role on wood, so the performance requirements of the coating film, water-based wood coating can be well met, such as water resistance and adhesion. In terms of plant construction requirements, faster drying performance is required to meet mass production. Because the thickness of each coating coating is thin, it avoids the defect that water-based wood coating drying is slightly slower than nitro coating. Antique furniture materials are mostly pine, oak, red cherries, the typical process is as follows→ material destruction to do old→ material substrate adjustment (red trim) →strout color→ head primer →Griss coloring→ primer→ → dry brush→ primer →print, oxtail, brush black edge and other special effects→ surface. Although the
is more complex, but because each coating film is thin, the entire coating process can generally be completed within 1 day. In addition to the above common uses, there are also some factories using water-based wood coating as a display stand, because the odor is very low, so popular.
source: Monkey St. Chemical.<