Painting environment - Determination of temperature and humidity

1. Determination of temperature

The construction process of industrial product coating is required to be carried out at a constant temperature, which is an important condition to ensure the quality of the coating film of the coated part . Generally, the coating process stipulates that the temperature of the coating and the object to be coated, the temperature of the spraying room, and the temperature of the drying room, etc., all need to be controlled according to the set temperature in order to ensure the stable quality of the coating film and avoid the disadvantages of the coating film. generation. If the drying room is too low, the drying of the coating film will be ineffective, and a series of mechanical properties affecting the coating film will not meet the standards. If the temperature is too high, it will cause over-baking, and it will also damage the performance of the coating film to a certain extent. Especially in the mechanized and continuous coating production line, it is more necessary to control the temperature within the range required by the process in order to stabilize the coating quality.

Temperature measurement method:

There are two kinds of contact and non-contact. Contact temperature measurement is suitable for determining low temperature , and a mercury thermometer can be used. Non-contact temperature measurement, used for high temperature measurement, using thermocouple thermometer , and through the thermometer, can automatically control the constant temperature, and can automatically record the temperature.

2. Determination of humidity

Another factor that affects the coating quality in the coating construction environment is air humidity. Air humidity is usually represented by relative humidity (R, H). It refers to the maximum . The ratio of relative humidity, usually expressed as a percentage. When the relative humidity is 100%, it means that the air is saturated with water. Usually, the relative humidity of the air is generally between 50% and 90%. When the air humidity is not saturated, the air becomes cold, the relative humidity rises, and the temperature drops. When the air humidity is saturated, the temperature at which moisture begins to condense is called the dew point. At this time, the condensation moisture will deposit on the surface of the coating film, which may cause the coating The corrosion of the object steel and the reduction of the adhesion of the coating film will prolong the drying time of the coating film, and the defects of loss of gloss and whitening will be more obvious for the coating film dried at room temperature. If the relative humidity is too low, it is easy to cause dust , cause the coating film to granulate, dry the coating film too quickly, and affect the disadvantages of poor leveling. Therefore, mastering and controlling the humidity and temperature of the construction environment is an important process parameter in the coating process.

Humidity measurement method

The method of measuring relative humidity is very simple. Generally, the difference between dry and wet bulb temperature is found by using a dry and wet bulb thermometer , and the relative humidity can be found out in a special conversion table.