Degreasing for Steel Before Enamel Coating

For enamel coating, the pretreatment of metal substrate is one of the most important process. For steel enamel coating, the pretreatment of steel body has different requirement according to different types of steel plate. Generally for enamel grade steel like DC01EK, DC04EK or DC06EK, there is only degreasing needed, to move out all the oils on the steel surface. While for the normal cold rolled steel plate (SPCC), after degreasing process, acid pickling or sand blasting may also needed to be applied before coating enamel on. To ensure the best coating effect and reduce the defect possibility causes from steel plate.

In this article, Nolifrit expert will let you know how a enamel factory make degreasing for the steel body before enamel coating. The detailed steps are as follows:

1. Tank 1#, the degreasant mixed with water by the 4-7% ratio, and soak the steel at 50-90 ° C for 3-6 minutes, and is added and replaced according to the production volume and the oil quality of the steel plate. If heating is required, the size of the tank is based on the heating equipment.

Instructions: A. Increase the water temperature to 40-50℃ so that the degreasing powder can easily dissolve.

  B. Add the degreasant powder slowly to ensure it dissolve completely.( You can also take      the specification of PEC-20 for reference).

2. Tank 2#, water only. After coming out of from the tank 1#, put the steel in the water, without soaking. put into and take out directly about 2-3 times.

3. Tank 3#, water only. Flowing water is the best. If don't have, need change it at least once a day. If the water of tank 2# is not enough, can add the water with the tank 3#.

4. Tank 4#, antirust agent. Add 10 kg of edible soda and 15 kg of sodium nitrite for per ton water. It may be different according to the local water quality, on the premise of not rusting in the production process, it needs to be soaking for 3-5 minutes, put into and take out for 3-5 times.