The monitoring of climatic conditions such as temperature, relative humidity, dewpoint and moisture in industry is often vital to the success of the application of a coating. These parameters determine both the conditions for the application of the coating, and the resulting quality and performance of the coated product.
In the protective coatings industry, moisture can form on the surface when the surface temperature is low enough to cause condensation from the atmosphere. The dewpoint temperature (Td) is the point at which this occurs.
Monitoring the surface tempearte (Ts) realtive to the air temperature (Ta) and its relative humidity (%RH) allows the dewpoint temperature to be calculated and compared to the surface temperature. This difference in temperature (TΔ) is the key parameter dictating when it is safe to apply the coating.
The temperature of the coating material is also important as temperature affects the coating′s shelf life, viscosity and its application characteristics.
The continuous monitoring of the climatic conditions during the cure process (drying) is also required. If the temperature is too high, the coating can dry too quickly, leading to surface defects. If the temperature is too low, the cure time is extended, leading to delays in applying a further coat, other types of surface defects may affect the further coat, such as amine blush.
The cure process for powder coating requires a specific temperature to be achieved for a specific period. Monitoring the oven profile allows the user to ensure that the product is brought to the appropriate temperature and held at that temperature for the specified time. If the oven or product is too hot, the coating can burn, if it is too cold, the coating does not cure, leading to poor adhesion and appearance.
The presence of moisture within a material will result in poor adhesion, premature coating failure and poor appearance. For example, applying a powder coating to a damp wooden panel will cause steam to be created when the panel passes through the curing oven, thus causing damage to the coating.
Elcometer offer a complete range of dewpoint and relative humidity meters, thermometers, digital thermometers, hygrometers, dataloggers, moisture meters and anemometers to monitor climatic conditions.