The test results of coating properties have a lot to do with whether the sampling is correct. The national standard GB 3186-82 stipulates specific sampling methods, and the specific requirements are as follows:
(1) Randomly sample from each batch of products, and the sampling number is 3% of the total number of packaging barrels of the same manufacturer (for batches of less than 100 barrels, no less than 3 barrels; for batches of less than 4 barrels, no less than 30#) .
(2) When sampling, open the lid of the barrel, visually observe the fluid paint product in the barrel, and record the surface condition, such as whether there is skinning, precipitation, layering, etc.
(3) Stir the paint in the barrel evenly, and the sample taken in each barrel should not be less than 0.5kg. Divide the sample into two parts, one part is about 0.4kg, and it should be sealed and stored for future reference, and the other part should be tested immediately. If the test results do not meet the specified value of the standard, the entire batch of products is deemed to be unqualified.
(4) Clean the sampling tube after use. Do not fill the container with samples, leave 5% space and cover tightly. Samples should be placed in clean, dry and well-sealed metal cans or glass, labeled with relevant details such as the date of sampling, and stored in a cool and dry place.
