Test of citric acid resistance of enamel

2022-07-04 0 By

The acid resistance of enamel products is one of the very important properties, many industrial enamel need to contact acidic substances, such as chemical reaction kettle, stirring paddle, chemical containers and so on, this kind of acid resistance of enamel has special high requirements of products, can purchase enamel acid resistant glaze, industrial acid resistant glaze to improve the acid resistance of products.And daily enamel ware, especially enamel pot, enamel bowl, enamel pot, because of contact with organic acid (acetic acid, citric acid, lactic acid, etc.), so need to have enamel layer with good resistance to organic acid performance.The following are the test methods and criteria for citric acid resistance of enamel products:Citric acid solution concentration 10%;2. Glass or polyethylene cover with an outer diameter of about 30mm;3. Filter paper with diameter of about 30mm;4. Pencil: Hardness is HB.(2) Test method: 1. Drop 2 to 4 drops of citric acid on each enamel steel plate with a straw, immediately cover it with a lid, and place it at 20 to 26℃ for 15min;2. If the test sample is curved, place 2 pieces of filter paper on the test sample and then drop 2 to 4 drops of citric acid on the filter paper.Immediately cover with a lid and leave at 20~26℃ for 15min;3. Remove the lid and filter paper, wash thoroughly with water, and blot dry with a clean cotton towel.Grade AA: there is no difference between acid treated area and untreated area;2. (Grade 2) GRADE A: There are differences, but there is no loss of light in the acid treated area. Draw parallel lines in both areas with A pencil and wipe them clean with A dry towel.3. (Grade 3) Grade B: there are differences, but there is no loss of light in the acid-treated area. Draw parallel lines in the two areas with a pencil, and wipe them with a dry towel, but wipe them with a wet towel;4. Can not be graded: acid treatment area loss of light, even using a wet towel can not wipe clean.