The humidity in the air is usually expressed by "relative humidity" (RH), which indicates the content of water vapor in the air at a certain temperature, and the relative humidity is usually expressed as a percentage. The relative humidity of the air is generally between 50% and 90%. When the relative humidity is 100%, it means that the moisture in the air is saturated and condensation begins. Conventionally, when the relative humidity exceeds 85%, the painting operation cannot be carried out. When the relative humidity exceeds 85%, the quality of the coating Most of them are relatively poor, prone to whitening, cracking, peeling, etc. Of course, some special coatings can be exceptions, such as the moisture-curing polyurethane coating commonly used in floor coating, which is cured by moisture in the atmosphere, While drying, humidification may be required for proper curing.
Humidity only affects floor coatings when it is too high, but its influence is far greater than people think. Excessive relative humidity may cause condensation on the coating surface. For solvent-based amine-cured epoxy coatings, condensed water will destroy the curing agent, causing whitening, loss of gloss, stickiness and stickiness of the coating film. For polyurethane coatings, if the humidity is too high, it is easy to cause problems such as shrinkage cavities and air bubbles. For solvent-free self-leveling coatings, too much humidity can easily cause color separation and loss of light, especially when the temperature is also low.
It should be emphasized that the humidity mentioned here does not only refer to the humidity during construction, but refers to the air humidity during construction and the whole process of coating film curing. If the paint takes two days to dry, it is required that the humidity should not exceed the standard within two days after construction. Therefore, the construction of the floor depends not only on the weather at that time, but also on the weather forecast.
