Winter is coming, about water-based coatings you should know about the "two or three things"!

Four mainstream environmental protection coatings
green office furniture has become increasingly popular, green environmental protection has gradually become an important consideration for consumers to buy furniture. At present, the market is more recognized four kinds of environmentally friendly furniture coatings are: UV paint, water-based UV paint, single-group water-based wood paint and two-part water-based wood paint.
UV
because UV coating curing fast, safe and environmentally friendly and excellent performance, well received by consumers, has a high market share

.
for products with special shapes, UV lamps can't reach the corners of the yin, and coatings can't cure.
water-based UV coating
water-based UV coating, that is, UV-cured water-based wood paint, combined with the environmental protection of traditional water-based coatings and UV-cured coating hardness, high transparency, yellow resistance excellent advantages, is a good performance of environmental protection paint.
Single-component water-based wood paint
single-component water-based paint is divided into three categories according to the main components:
(1) acrylic water-based paint
the main component is acrylic emulsion, can maintain the original color of the wood, but wear resistance and chemical performance is poor, generally used as water-based wood primer.
(2) Acrylic and polyurethane synthesis
acrylic and polyurethane synthesis of wear resistance and chemical resistance is better than acrylic water-based paint, paint film hardness is good, comprehensive performance close to oily paint, is currently the backbone of the development of water-based paint.
(3) pure polyurethane water-based paint
pure polyurethane water-based paint comprehensive performance is superior, in terms of service life, color deployment has obvious advantages, is a high-end products in water-based wood paint.
tive-part water-based wood paint
in order to further improve the performance of the paint film, on the basis of a single-part water-based paint to add curing agent to assist the film, so that the film polymer chemical reaction, the production of two-part water-based wood paint.
two-part water-resistant wood lacquer film water resistance, resistance, stain resistance, anti-adhesion, hardness anti-scratch, iron resistance, wear resistance and other performance has been significantly improved.
From the above four environmental protection coatings can be seen, the use of water-based coatings has been a major trend recognized by the relevant industries, although there are many difficulties to be overcome to be efficient operation, a lot of technology needs to be further improved, but it is only a matter of time.
water-based coatings in the general trend
Today we mainly talk about the way water-based paints are used in practice methods and precautions.
I. Spraying techniques
In the water-based coating construction process, the surface of the object can be coated with spray method, you can obtain a thin and uniform coating film, for different geometric shapes, there are small holes, gaps, uneven uneven places, the paint can be evenly distributed;
current spraying method is one of the most important methods in the construction process of water-based coatings.
seven tips for spraying water-like paint below.
technique 1, control the appropriate viscosity
with clean water to the coating viscosity, to apply -4 viscosity meter measurement, the appropriate viscosity is generally 20 to 30 seconds. Usually the lacquer liquid into a straight line, instantly cut off the flow, into a drop down, this viscosity is appropriate.
2, control the appropriate air pressure
in the water-based coating spraying construction operation, its air pressure is best within 0.3-0.4 megapa. Too little pressure, affecting the overall effect, and too much pressure, not only waste material, but also threaten the health of the operator.
Tip 3, control the appropriate distance
the distance between the nozzle and surface is generally 300 to 400 mm is appropriate, of course, can also be 10 mm to 50 mm between a small range of adjustment, if not in the range, it is difficult to obtain the most ideal paint film.
4, control speed angle
spray gun can be up and down, left and right movement, 10-12 meters / minute speed even operation for the best. The nozzle should be sprayed flat on the surface to minimize oblique spraying.
technique 5, avoid leakage spray
spray to the next one to press 1/3 or 1/4, so that there will be no leakage. When spraying fast dry paint, it needs to be sprayed sequentially at once, and the resaling effect is not ideal.
6, strong wind station wind
in outdoor spraying, we must pay attention to the wind, high winds should not be water-based paint spraying construction. In order to avoid caused ugly grainy surfaces, the operator should stand in the direction of the wind during operation.
Soptical 7, follow the principle of sequential
in general, in order not to cause the paint spray spray splashed on the sprayed paint film, damage has been sprayed paint film, water-based paint spray construction operation should follow: first difficult, then easy, first in and out, first high and then low, first small and then big principle.
, drying method
in many difficulties, drying technology is one of them. There are many drying methods of water-based wood paint, and different drying methods are obviously different in the drying speed and film quality of water-based coatings.
1, natural drying
natural drying method is simple, widely used, the disadvantage is slow drying speed. Under natural conditions, factors such as temperature, humidity and wind speed are uncontrollable, resulting in unstable drying speed and film quality.
If the high temperature, high humidity or humidity is relatively large conditions, the coating is easy to whiten, the drying speed is slow, at low temperature, the drying speed is very slow, especially when the temperature is less than 5 degrees C, water-based coatings are difficult to form a film. These are all applications that limit the implementation of water-based coatings.
2, hot air drying
hot air drying is the use of cont flow principle, the temperature of 40 to 60 degrees C of hot air as a heat carrier, the heat energy transmitted to the surface of the workware coating, the coating absorbs energy after curing into a membrane heating and drying method.
the use of hot air drying process, can significantly speed up the coating drying speed, and has a strong compliance characteristics, is a more common application of drying methods.
3, microwave drying
microwave drying is the principle of media loss. The diele thering constant of water is much larger than that of dry matter, so the moisture in the coating absorbs most of the energy released by the electromagnetic field.
advantage of microwave drying is that the drying speed is particularly fast, there is no shape requirement for the dried object, the heating of the coating film is very average, there is no temperature gradient, can be applied to the drying of thick film.
4, UV
for water-based UV wood coating, can use UV curing drying. In the water-based UV coating contains a small amount of photosensitive agent, in the light of ultraviolet light, triggering the polymerization reaction of film-forming substances, forming a mesh structure and making the coating cured.
UV curing has the characteristics of fast coating curing speed and good film quality, but this method can only be used to dry water-based UV coating, and can only be dried into flat-panel furniture coating board.
5, infrared drying
the so-called infrared curing actually refers to the painted furniture parts and their coating in the infrared light, absorbing radiant energy and converted into heat energy, thus completing the curing of the coating.
by wavelength range, can be divided into "near", "medium" and "far" infrared, commonly used far-infrared dry coating.
infrared curing has the advantages of fast curing speed, heating speed, good curing quality, but when using infrared heating drying coating, the coating has a clear temperature gradient, its drying is extended from the outside to the inside, which makes it not suitable for drying thick coating film.
the dry form of light-cured coating has the advantages of fast curing speed and good film quality, and has gradually become a common way of water-based coating curing.
researchers have carried out a lot of in-depth research in the field of photo-cured water-based coatings. At present, the development of photo-cured water-based coatings in China has gone through four important stages.
Three, four generations of photo-cured water-based coatings
water-based photo-cured coatings in wood and wood coating has a high application value, especially in plywood and molded wood coating is more advantageous. The use of low-solid content varnish, with excellent wood texture display, can increase the wood aesthetic.
the importance of environmental protection and other factors, photo-cured water-based coating technology in recent years in Europe and the United States advanced countries developed rapidly, has patented technology and products.
with the domestic environmental regulations are becoming more and more perfect and strict, photo-cured water-based coating technology will also set off a research boom in the industry.
The first generation of photo-cured water-based coatings - outer emulsification type
by the addition of surfactants (emulsizers), supplemented by high shearing force, it is possible to emulsify the traditional photo-cured resin into a water dispersion system. This emulsion has a high solid content, can directly use off-the-go coating raw materials, the production process is simpler.
But this external emulsified coating is very sensitive to changes in PH values, and one of the disadvantages is that the added emulsizer is still in the coating film after curing, which reduces its moisture resistance and affects the quality of the dry film.
The second generation of photo-cured water-based coatings -
nant-based self-emulsification type
in order to avoid the addition of emulsification agents, the non-ionized hydro-water chain segment into the resin, so that the resin can be stable dispersion in the water.
because the resin itself has hydrophobic, so no need to be added emulsifying agent can also be stable dispersion, the system pH value will not be as sensitive as the outer emulsified coating. This system can be subdivided into water-soluble and water-dispersed systems.
because the molecular chain with hydro-hydro-based groups, it will not be eliminated after photo-curing, so this type of coating compared to traditional photo-curing coatings, its curing film has poor water resistance and chemical resistance.
Third generation photo-cured water-based coatings -
mixed with water-dispersed resins
mixed by photo-cured hydrophospheric polymers with physically dry water dispersion resins (usually acrylic resins), photo-cured polymer parts dispersed in the water phase by non-photo-cured water-dispersed acrylic resins.
compared to the first generation of photo-cured water-based coatings, this is equivalent to replacing emulsifying agents with large molecule emulsions. Because the content of photo-curing parts in the whole system is low, the cross-link density of the resulting curing film is not high, so compared with the traditional photo-curing system, its chemical resistance is low.
The fourth generation of photo-cured water-based coatings -
ion-based self-emulsification type
introduces the ion base into the resin skeleton, and then uses anti-ion neutralization and ions on the molecular chain, so that the resin has a good self-emulsification properties.
good wetting, small particles can be formed in the water, so the preservation period can be very long, while having very good shear stability.
over time, photo-cured water-based coatings will develop even more. By then, the threshold for the use of water-based coatings in the new generation will be lowered repeatedly, but at the time, the use of water-based coatings must be strictly in accordance with its conditions of use.
, winter water-like wood paint construction process
wood paint in addition to environmental protection and other excellent performance, the construction process is also a very sophisticated problem. Winter has come, in winter when using water-based coatings, be sure to pay attention to two aspects: temperature and humidity!
(1) the construction temperature is kept above 5 degrees C
construction needs to ensure that the indoor plate temperature during construction and within 24 hours after construction is not less than 5 degrees C.
(2) humidity within 30-80% of the construction
must ensure that the construction process and within 24 hours after the construction of indoor humidity within 30-80%.
how to control the temperature and humidity, please look below!
1, take measures to increase temperature and dehumidification
if there is no heating in the room under construction, you can use 2 to 3 1000 to 2000 watts of tungsten iodine lamp (small sun) or use a heater, improve indoor temperature, accelerate the drying speed of paint film;
If the humidity is too high, you can use a dehumidifier to dehumidification method,
if the humidity is too low, such as in the Northeast and Northwest regions have heating rooms, you can sprinkle water on the ground, increase humidity, prevent water-based paint film dry too fast, causing the surface orange peel or cracking.
2, with warm water paint and warm water insulation
(1) with 40-60 degrees C of warm water paint, water temperature increased after the paint volatilization speed is faster, can improve the drying speed of water-like paint
;
3, thin coating construction
winter construction should avoid a single thick coating. Thin coating can speed up the drying speed, thus reducing the probability of problems, especially near the heating sheet must be thin coating.
4, the construction time period of the
recommended after 10 a.m. to 3 p.m. construction.
It is important to note that when working hours do a good job of indoor insulation work, to avoid opening windows (open windows can allow outdoor moisture and cold air convented into the room), local air flow too fast will lead to difficult to control the cracking of the paint film.
5, pay attention to the construction of substrate near the outdoor
doors and windows are closer to the outdoor, vulnerable to outdoor low temperature and high humidity, paint film is more prone to problems, so pay more attention to the construction of this part of the place.
conclusion
The current development of water-based environmental protection coatings is not mature enough, the cost is higher, for more low- and medium-term consumer markets, is still the world of oily coatings.
with the introduction of a series of environmental protection policies, to promote the rapid development of environmental protection coatings, many domestic enterprises have poured into the water-based environmental protection coatings market, upgrade the transformation or increase investment in water-based coatings research and development.
the development of water-based coatings and the market share in the year-on-year growth is an indisputable fact, and there is a trend of accelerating, the future water-based environmental protection coatings industry market will develop rapidly.