Construction process and precautions of waterborne paint
With the introduction of various environmental protection policies, furniture industry is the first to bear the brunt. The most intuitive is the use of water-based paint, its excellent environmental performance has been vigorously promoted in the market, however, the official use of water-based paint in China is not long, compared with the operation process of oil-based paint is not mature. Today we will briefly talk about how to standardize the technological process of waterborne paint.
I. what is waterborne paint
Water based paint is a kind of film-forming material with water-soluble resin, represented by polyvinyl alcohol and its various modifiers. In addition, there are water-soluble alkyd resin, water-soluble epoxy resin and inorganic high polymer water-based resin.
- The biggest advantage of waterborne paint — environmental protection
Traditional oil paint contains more than 85% organic solvent, while water paint only contains 10% organic solvent, so VOC emission is low. At the same time, the water-based paint has better coating characteristics, good permeability and glossiness.
- Disadvantages of water-based paint: long volatilization time
Compared with solvent based paint, water-based paint has the characteristics of low volatilization rate, high surface tension, high conductivity, corrosiveness and easy to produce bubbles, which leads to the difference between water-based paint and solvent based paint in terms of equipment and construction technology.
II. Process flow of waterborne paint
- Wood treatment
Before painting, first of all, clean the wood, in order to effectively remove the stains, hairs and thorns on the wood, and make the wood surface clean and smooth, so as to save labor and material for subsequent painting.
- Wood sealing
The prepared special wood sealer can effectively seal the wood and prevent the wood from being polluted.
Kaikang chemical water based two-component sealing primer
Wood sealing can prevent excessive moisture absorption, moisture dissipation and wood deformation, enhance the adhesion between paint film and wood, save paint consumption, and enhance the hardness of paint film.
Select the matching wood putty. After mixing, scrape and apply the putty to the wood hole. After the putty is completely dried, sand paper shall be used to polish and thoroughly clean the putty on the wood.
Filling wooden holes with putty can reduce the amount of wood paint and improve the smoothness of paint film. Different painting effects have different requirements for putty scraping and coating. For example, to make an open effect, the putty color should be the same as the wood color before scraping.
- Primer construction
According to the required proportion of wood primer, brush or spray can be used. The function of primer construction is to fill the wooden holes and increase the thickness of paint film.
During construction, after the primer is dry, it must be thoroughly polished with sandpaper, and then the primer shall be applied again. It is required to paint evenly without sagging and fill the wooden hole smoothly.
- Sanding treatment
Sanding wood with sandpaper is actually a step throughout the whole wood paint construction process. During wood treatment, sanding is required, putty scraping is required, primer construction is required, and finishing coat is required before and after construction.
The sanding process is critical. Sanding makes the wood smoother, smoother and easier to paint. Sanding after painting makes the surface of paint film flat and smooth. But pay attention to avoid cross sand during sanding, and do not use too coarse sandpaper for grinding.
- Finishing coat construction
Before finishing coat construction, the wood surface must be cleaned again to remove dust particles, so that the paint film surface can have better coating effect. Each time the finishing coat is applied, it should not be too thick at one time. It is better to apply it many times, and the construction of the next layer should be done after the paint film is dry.
The finishing coat construction directly affects the final effect of the paint film. The finishing coat construction requires uniform application, no sagging, good glossiness, no obvious brush marks, and smooth and delicate feel.
III. precautions for construction of waterborne wood paint
- The temperature of the construction site shall be more than 8 ℃, and the relative humidity shall be less than 85%. The construction temperature of 10-50 ℃ and the humidity of 40-70% are the best, and the moisture content of wood is less than 15%.
- Before use, the wool brush shall be fully soaked in clear water to remove foreign matters and electrolytes. Otherwise, the brush and water-based paint are easy to agglomerate. After use, the brush shall be cleaned immediately and cannot be placed in the prepared paint.
- Please use purified water or distilled water for dilution. If you want to use tap water, you should carefully prepare the paint for 15 minutes and use it without abnormality.
- Before paint preparation, it should be stirred evenly. After paint preparation, it should be left for 10 minutes and then filtered for use. After use, please immediately seal the tank mouth to avoid the entry of harmful substances.
- If the paint is not used up or the construction interval is too long, it shall be covered immediately to avoid affecting the construction effect.
- The waterborne wood paint is sensitive to salt, and the base material polluted by sweat and other salts shall be cleaned in time, otherwise the adhesion and apparent effect will be affected.
- When applying water-based wood paint, do not drag it back and forth. Brush it thinly and lightly along the same direction of wood grain upward or downward.
- When spraying the water-based paint, follow the principle of “thin spraying for many times”. The one-time spraying should be thinner to avoid cracking.
- When spraying the top coat, it must be in a dust-free environment to avoid pollution.