Determination of pH value of electrophoretic paint - PH meter is easy to do

Electrophoretic coating technology originated in the automotive industry. It is a new type of body primer method (including new electrophoretic coating, electrophoretic coating process, coating equipment and supporting equipment) developed to meet the requirements of the automobile body painting process and solve the problems existing in the automobile body primer coating process. Accessories). It is the mainstream coating method of today's automobile body primer process.

Electrophoretic coatings have the advantages of being effective, good, safe, and economical in practical applications. It has been valued by the coating industry all over the world. With the development of new electrophoretic coatings and the advancement of coating technology, especially the development of cationic electrophoretic coatings and cathodic electrophoretic coating technology (the world's first cathodic electrophoretic coating line for car bodies was put into production in the United States in 1977), electrophoretic coating The craft has gained popularity rapidly. In 1965, only 1% of body primers used electrophoretic coatings, and in 1970 the proportion was 10%. In 1985, the rate of cathodic electrophoretic coating on car bodies reached over 90%. Today, almost 100% of car bodies are painted by cathodic electrophoretic coating. It has been promoted and applied by the automobile industry to industrial fields such as building materials, light industry, agricultural machinery, and household appliances.

PH value determination method

(1) Determination steps

① Preheat and debug the pH meter according to the pH meter’s instruction manual

② Calibrate the pH meter with standard buffer solution. If the pH value of the solution to be tested is between 6 and 7, calibrate with the standard solution of pH=6.864; if the pH value of the solution to be tested is between 8 and 9, use the standard solution of pH=9.182 for calibration

③Keep the temperature of the banyan tree solution to be tested the same as the temperature displayed on the p meter (generally 25°C)

④ Preparation of the solution to be tested

(2) Results and Presentation

The measurement result is represented by three "arithmetic mean values of the measured values".

(3) Precautions for testing

① During the measurement process, the electrodes are easily polluted. In this case, it can be soaked in dilute acetic acid solution for a while, and then rinsed off with plenty of deionized water.

② The standard buffer solution will change with time and should be replaced regularly

③ Regularly add saturated potassium chloride solution to the calomel electrode.

④ It is forbidden to wipe the glass ball of the glass electrode to prevent damage to the ion membrane on the outer surface of the glass ball. You can gently absorb attached droplets or water droplets with filter paper.

⑤ If measuring cathodic electrophoretic paint and anodic electrophoretic paint at the same time, use two acidity meters respectively.

⑥ It is not recommended to use composite electrodes.