1. Matters needing attention in the production of PU matte series:
1. About the glossiness of matte varnish. There are many reasons that affect the gloss of matte varnishes, including the thickness of the paint sprayed, the drying speed of the paint, the degree of uniformity before spraying, the ventilation of the production site, and the relative humidity of the air in the production site, all of which have an impact on the gloss of the paint. .
2. For some paints, different curing agents, different solvent powers of thinners, different volatilization speeds, and different film thicknesses will all affect the performance and matteness of the final paint film, so we must pay attention to it during production. Use supporting curing agent, thinner, etc.
3. Thinners with corresponding volatilization speeds should be selected in different seasons. If the volatilization speed of thinners is too slow, it will easily cause the paint film to bloom and sand. If the volatilization speed is too fast, it will easily cause product quality accidents such as whitening, loss of gloss, insufficient leveling, and poor adhesion.
4. The influence of winter on paint. The viscosity of paint is greatly affected by temperature. As the temperature increases, the viscosity decreases, and as the temperature decreases, the viscosity increases. In this way, in winter, the diluent will increase, the viscosity will become lower, and quality problems such as poor fullness, sanding, poor hand feeling, reduced gloss, and poor sand mark covering ability will easily occur. Therefore, pay attention to the storage temperature of the paint in winter, and the temperature of the paint mixing place should be kept the same as possible.
2. Precautions for the production of PU white topcoat
1. If you want to make a bright white finish with a better static surface effect and hope to keep it unchanged for a long time, you need to start with the selection of MDF. In the comparison of application experiments, the fiberboard with better density will not deform. Obviously to a lesser extent. After the fiberboard with poor density is finished with bright white surface, it will obviously deform after a period of time, especially when using PU white bottom, it will become more severe, so it is recommended to choose a good density board when choosing MDF.
2. In terms of primer, the bright white finish made of PE white primer is obviously better than PU primer in terms of static surface effect and long-term shape, especially when the density of MDF is poor. more obvious.
3. Before spraying the glossy white topcoat, polish the white base of the lower layer, which can directly affect the final effect of the glossy white surface and the amount of topcoat used. If the sandpaper is too coarse, the fullness and static effect of the surface will be affected. It will look obviously worse. If you use fine sandpaper or water grinding once at the end, you can spray less paint when spraying the white topcoat, and you can still get a better static surface effect and fullness (the white topcoat of some paint manufacturers is different from the curing agent. The matching requirements are quite strict, misuse or abuse of curing agent will not only affect the yellowing resistance, but also will significantly change other properties).
3. Matters needing attention in the production of PU bright light series
1. Because the drying time of bright paint is relatively longer than that of matte paint, it is necessary to ensure that there are no impurities on the surface of bright paint, and the requirements for the sealing and cleanliness of the spray booth are stricter. In addition, it should be noted that when doing sanitation, most of them will sprinkle water on the ground of the drying room or wash the room with water, because the drying room itself is well closed and the temperature is relatively high, which will form a high temperature and high humidity environment, making the varnish Easier to bubble up. Therefore, manufacturers especially recommend that the temperature of the drying room be controlled at about 25 degrees, which will improve the pass rate of the product.
2. In the production of leather or sticker furniture, the sealing treatment of the substrate and the primer selected on the paper will affect the gloss of the glossy paint. Because the solvent resistance of ordinary PU primers is poor, spraying bright light on it will easily cause leveling Poor durability, uneven surface, gloss and fullness maintenance will be obviously poor, therefore, if you want to get a better mirror effect, properly increase the amount of curing agent for the primer, which will affect the surface effect of the topcoat has improved.
4. Precautions for the production of colored transparent topcoat (also known as color repair topcoat)
1. The transparent and colored topcoat is transparent and colored. Pay attention to the uniformity of the gun during construction, do not spray too thickly at one time, and the final color should be sprayed several times. Otherwise, it is easy to cause uneven color shades and affect the appearance of the product.
2. Combined with the bottom coloring process, the paint film effect is more three-dimensional and layered.
Five, other about PU paint
1. Curing agent:
Generally, the curing agent of foreign products is common, and there is only the difference between the primer curing agent and the topcoat curing agent. Domestic paints are much more complicated, so the curing agent must be correctly selected during production. Different types of paints in CHINA have different requirements for curing agents due to differences in systems. Pay attention to the choice of curing agent during use, otherwise it will easily cause uncertainty in hardness, gloss, scratch resistance, hand feeling, and antiperspiration. In addition, the amount of curing agent added must be correct, otherwise it will cause abnormal gloss and hardness. .
Note: Misunderstandings should strictly distinguish the conceptual difference between curing agent and drier. Increasing or decreasing the amount of curing agent is not the correct way to adjust the drying speed of the paint film. Reducing the amount of curing agent will have a bad effect on the paint film.
2. Thinner: Thinner is also called bottom water.
Pine perfume: It has a high boiling point and dries slowly. It is a solvent for diluting Grace. The solvent dries slowly and has the advantage of being easy to wipe.
Slow-drying water: It is used to improve the high-humidity whitening phenomenon caused by the rainy season. The amount of slow-drying water added is generally controlled at about 10%, and the specific situation is subject to the data provided by the manufacturer.
6. Precautions for the production of special paints
1. About imitation leather paint: the introduction of imitation leather paint is a kind of special effect paint, which belongs to a kind of art paint. It is fast drying, high hardness and good wear resistance. After hard drying, the surface of the paint film has a uniform sandy appearance, with lamb skin feel. Used for coating of office furniture and cabinet series.
How to use: Process:
Blank - closed - sanding - PU solid color primer - sanding - PU solid color primer - sanding - imitation leather paint.
Precautions:
The construction method is basically the same as that of ordinary polyester paint. During construction, the air pressure of the Spray Gun, the amount of oil output and the thickness of the coating can be controlled to obtain different imitation leather effects.
2. About cracked paint: It can make the paint film show uniform and different cracks, with excellent adhesion, and the pattern size will be different according to the thickness of the paint film. How to use: Spray cracked paint, generally spray 2 "+" characters to cover all the substrate. The crackle paint is adjusted to a suitable viscosity. Generally, a "+" character can be sprayed to achieve a satisfactory pattern, but the requirements for the personal technical level of the workers are higher, and the spraying needs to be uniform and the gun should be moved at a uniform speed. If the crack needs to increase, it can be properly sprayed with 1-2 "+" characters. Note that it should be protected with PU or NC transparent topcoat at the end.
Construction process: base material - filling and sanding - NC solid color base or gold base (completely covered) - crack paint - NC or PU top coat (the PU top coat is required to be sprayed thinly to avoid completely dissolving the crack paint).
Production Notes:
A. Adjust the appropriate spray viscosity (it is required to keep the consistency of viscosity every time you spray).
B. The spraying should be uniform, otherwise the cracks will be different in size (it is required to be sprayed by the same person for the same design and color each time, and the worker's proficiency is required to be high).
C. Do not use water cement or gypsum putty as the primer for cracked paint.
D. Pay attention to the use of matching products during construction.
E. Due to the heavy color of the cracked paint system, after the cracked paint is applied, it should be covered with clear topcoat for protection. Otherwise, there will be coating disadvantages such as poor adhesion.
G. If white cracked paint is sprayed, it should be finished with anti-yellowing varnish, otherwise it is easy to yellow.
3. About pearl paint series: Pearl paint has a colorful flash effect, rich luster, elegant tone, and strong three-dimensional effect.
