What are the disadvantages of waterborne paint for children?

What are the disadvantages of waterborne paint for children?

1. Water-based coating has high requirements for the cleanliness of the construction process and the surface of the material, and the surface tension of water is large, so the dirt is easy to shrink on the coating.

2. Water-based coating has strong mechanical force and poor dispersion stability. When the flow rate in the water pipeline changes rapidly, the dispersed particles will be compressed into solid particles, and the coating will produce pitting. The water pipe should be in good shape and the wall should be free from defects.

3. Water-based coating is very corrosive to the coating equipment, and the use of anti-corrosion lining or stainless steel materials, the equipment manufacturing price is high. Waterborne coatings need to precipitate corrosion, metal dissolution and dispersed particles of water pipes, coating to generate pitting, using stainless steel pipes.

4. Water-based coating for construction environmental conditions (temperature, humidity) requirements are more strict, increase the input of temperature control and humidity regulation equipment, but also increase energy consumption.

5, water evaporation latent heat, baking energy consumption. Cathodic electrophoretic paint should be baked at 180. Latex paint takes a long time to dry completely.

6. Organic solvents with high boiling point will produce a lot of lampblack when baking, and then drop on the surface of the coating after condensation, affecting the appearance.

What is the performance of children's waterborne paint?

(1) Poor pigment dispersion.

Waterborne coatings belong to polymer dispersion system, the dispersion of pigment is not good, measures should be taken to improve.

(2) Poor stability of dispersed particles.

Dissolved molecules are stable to shear force, heat, pH, etc., while dispersed particles are unstable, so stabilization measures are taken for dispersed systems. Dispersed particles can be destroyed by shear forces, so shear forces should be avoided in the manufacture and transportation of water-based coatings. Dispersed particles sensitive to pH value, paint mixed with acidic substances will form acid particles, the formation of gelatin, damage water-based paint. In addition, water-based coatings can also destroy dispersed particles when frozen in cold during transportation.

(3) large surface tension.

The surface tension of water is large, the surface tension of children's waterborne paint is also large, and the management should be strengthened in the construction process. Otherwise, coating time.

Easy to cause the following defects and film defects:

A. Easy to hang.

B. Poor flatness.

C. Shrinkage holes, pinholes are easy to produce.

D. Small seams that do not easily enter the surface of the coating.

(4) High evaporation heat and heat capacity, greatly affected by temperature and humidity.

The high evaporation heat and heat capacity of water make the water in waterborne coatings evaporate slowly. About 50% of the total solvent in solvent-based coatings is volatilized in the spray mist process, while only 25% in water-based coatings. Water evaporation is slow, easy to produce oil, reduce the efficiency of color. Therefore, an intermediate heating zone is set to force the water to evaporate on the water-based primer coating. Remove 90% of the water from the water-based primer coating before spraying the varnish (to prevent boiling water from evaporating through the varnish during baking). Therefore, a water-based primer prevents the varnish from dissolving.

The evaporation rate of water is closely related to the relative humidity. When the relative humidity is high, the evaporation rate of water is very low. Therefore, the relative humidity and temperature of the children's water-based paint room are controlled within a certain range to ensure that the right amount of water volatilizes in the spray atomization process, and the water and organic solvents maintain an appropriate balance in the coating. This proper balance gives children's waterborne paint the right surface tension to make the spray surface wet.