外墻涂裝出現泛堿褪色,它對外觀裝飾效果具有極大的破壞性。大雨過后,涂料顏色往往發花、發白,嚴重的還會出現起皺,甚至是漆膜消失,這其實是外墻涂料泛堿的原因。
The exterior wall painting is fading with alkali, and it has great destructiveness to the exterior decoration effect. After the heavy rain, the color of the paints often becomes flower and white. Serious wrinkles will appear, even the paint film will disappear. This is actually the reason why the exterior wall paint is alkaline.
如果基層和膩子層中含有大量未聚合的水泥或石灰,下雨時雨水會涌進膩子層和基層,天晴后水汽會把這些堿性物質帶到涂層,在表面形成一層白色物質。同時因其高堿性導致涂層中顏料發生變色、褪色。
If a large amount of unpolymerized cement or lime is contained in the base and the putty, the rain will pour into the putty and the base, and the water vapor will bring these alkaline substances to the coating and form a layer of white material on the surface. At the same time, because of its high alkalinity, the pigment in the coating will change color and fade.
外墻涂料泛堿的解決方法
Solving method of Pan alkali in exterior wall coating
1、消除基層堿性主要是砂漿抹灰層的養護,可以澆水3-4次,使水泥完全聚合,則其堿性會很快下降。如果不具備澆水條件,靠自然雨水和自然聚合,則干燥的時間會更長,至少要20天以上(冬天可能要30天以上)因此,砂漿抹灰層的澆水養護是比較好的降堿方法。當然,水泥的選擇也是很重要,選用合格達標的水泥是基礎。
1, the elimination of basic alkali is mainly the maintenance of mortar plastering layer, can be watered for 3-4 times, so that the cement completely polymerized, its alkalinity will soon decline. If water conditions are not available, the drying time will be longer, at least for more than 20 days (or more than 30 days in winter). Therefore, the water maintenance of the mortar plastering layer is a better method of reducing alkali. Of course, the choice of cement is also very important. The selection of qualified cement is the foundation.
2、消除膩子層堿性主要是選用質量好的找平膩子,這種膩子不但硬度好且耐水,堿性不高(PH值小于10),關鍵是提高膩子中的粘合物(乳膠)用量,減少水泥用量,同時膩子施工好后要及時澆水1-2次,使膩子層中的水泥能完全聚合硬化,這樣PH值也能降低。市場上有些低端膩子(1000元/噸以下的)完全靠水泥來提高粘結力,又沒有及時淋雨養護,導致PH達到10以上(有的達14),這種情況肯定會出現泛堿。
2. To eliminate the alkalinity of the putty is mainly the selection of good leveling putty. This putty not only has good hardness and water resistance, but not high (pH value less than 10). The key is to improve the amount of adhesive (latex) in putty and reduce the amount of cement. At the same time, the putty should be poured in time 1-2 times after the putty is well constructed, so that the cement in the putty can be completely used. Polymerization of hardening, so that the pH can also be reduced. On the market, some low-end putty (1000 yuan / tons below) completely rely on cement to improve the cohesive force, and no timely rain maintenance, resulting in PH up to 10 (some 14), this situation will certainly appear in the case of alkali.
3、選用封閉性好的底漆對基層和膩子層進行滲透封閉,使堿性物質難以隨水汽滲透到涂層,這是種治標的方法。但如果底漆滲透封閉性不好或基層膩子堿性物質過多(PH>10),則還是會出現泛堿現象,要使底漆更好滲透,底漆乳液粒徑要細,粘度要低。
3. Choose a good primer to seal the base layer and putty layer, so that it is difficult for the alkaline material to permeate the coating with water vapor. This is a temporary solution. However, if the primer is not well sealed or the basic substance of the base putty is too much (PH>10), there will be a common alkali phenomenon. To make the primer better permeate the primer, the size of the primer is fine and the viscosity is low.