Paint knowledge | why is the paint film of furniture easy to turn white?

Key tip: A: more and more furniture factories use printed wood grain paper instead of veneer to produce furniture On the one hand, it can save limited wood resources and maintain a good ecological environment On the other hand, it can greatly reduce production costs for furniture factories Therefore, sticker furniture has become popular in the market in recent years Many paster furniture factories generally encounter many problems in the production process, which is that the paint film sprayed by paster furniture is easy to turn white, some turn white before the paint film is dry on site, and some turn white after the furniture is placed for a period of time To find out the cause of whitening, we should first understand the production process adopted by the furniture factory, Which is the price of Dajin diatom mud Recommended brief introduction: which is the price of Dajin diatom mud? How to buy genuine diatom mud? Guangdong diatom mud agent suggests placing a basin of cold water in the air conditioning room, so that the diatom mud wall can breathe effectively The feature of the breathing wall is obvious When the indoor air is dry, the diatom mud wall will release the absorbed water quickly Put it out to help regulate the indoor dry humidity It is suggested to place a basin of cold water in the air conditioning room, so that the wall of diatom mud can breathe effectively The feature of the wall that can breathe is obvious When the indoor air is relatively dry, the wall of diatom mud will absorb the water Paint Home News: A: more and more furniture factories use printed wood grain paper instead of wood veneer to produce furniture On the one hand, it can save limited wood resources and maintain a good ecological environment On the other hand, it can greatly reduce production costs for furniture factories Therefore, sticker furniture has become popular in the market in recent years Many paster furniture factories generally encounter many problems in the production process, which is that the paint film sprayed by paster furniture is easy to turn white, some turn white before the paint film is dry on site, and some turn white after the furniture is placed for a period of time To find out the cause of whiteness, first of all, we need to understand the production process adopted by the furniture factory At present, there are mainly two kinds of processes as follows: one is the process commonly used by the furniture factory: white blank (MDF) water cement bottom Debao sticker (white emulsion) Pu or PE primer (two times) finish (two times) The other is the process used in the production of high-grade furniture: White (MDF) with a water-cement base, Debao Pu or PE primer sticker (with white emulsion), Pu or PE primer paint It can be seen from the above two kinds of stickers: at present, the stickers widely used in furniture factories are white latex, which belongs to water-based adhesive There is a large amount of moisture in the adhesive (moisture content can be more than 40%), so there should be enough time for full drying after the completion of the stickers The reasons why the paint starts to turn white at the spraying site (before the paint film is dry) are: ① the relative humidity in the air of the spraying room is high; ② the paint is sprayed before the white emulsion is completely solidified; ③ the water is mixed in the air pipe system; ④ the drying is not complete after the water sand In these four cases, the water directly contacts with the paint, resulting in the substantial whitening of the paint film caused by the immiscibility of the water emulsion The measures to prevent this whitening are as follows: ① the relative humidity in the air shall be appropriate, and the operation shall not be carried out when the humidity is too high; ② the white latex layer shall be fully solidified to make the water in the rubber layer volatilize clean; ③ the air compressor system shall be checked, and the water in the air compressor shall be discharged in time; ④ the water sand shall be fully dried, generally at room temperature (250C, relative humidity 75%), and shall be dried Spray the next coat of paint in 7 hours However, no whitening was found at the spraying site, and it took a period of time (less than 10 days and a half months, more than 2-3 months) to gradually whiten The reasons are: ① the moisture content of the base material is too high, which exceeds the local equilibrium moisture content; ② the water content of the white emulsion penetrating into the base material and the wood grain paper and the residual water content of the white emulsion itself are not evaporated In both cases, the paint does not contact water directly before the film is dry, and will not turn white before or after the film is dry for a short time But after a period of storage, or after the furniture is transported from the south to the north, the water will slowly release in the form of water vapor with the change of environmental conditions At the junction of the closed paint film and paper, a certain pressure will be formed The paint film will be lifted to separate the paint film from the paper After the separation, the water vapor will accumulate in the space After the refraction of the light, it looks like white and foggy If the blade is used to cut the area, it can be found that the white area has been separated from the layer This kind of whitening is not the whitening of the paint film itself, but a kind of "delamination" whitening In order to prevent this "delamination" whitening, the following measures should be taken: ① the moisture content of the base material should not be too high, which should be equivalent to the local equilibrium moisture content; ② there should be enough drying time after the sticker to remove the residual moisture Generally, the primer can only be sprayed after drying at room temperature (250C, relative humidity 75%) for at least 7 hours It is very difficult to repair the paint film after it turns white Therefore, it is suggested that the furniture factory should take precautions to avoid unnecessary loss Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,