The monotonous process requires both paint and ink to be dried in a tunnel oven. The monotonic conditions of iron printing ink are generally between 130 ℃ and 160 ℃, and the time is controlled within about 10 minutes. The monotonic strip of the coating is between f '-170 ℃ and 210 ℃, and the length of the underground oven is about 30 meters. It consists of three stages: heating zone, constant temperature zone, and cooling zone.
Heating up is the stage after the tinplate enters the oven. The primary function is to raise the tinplate from room temperature to the set temperature constant temperature zone. The primary function is to adhere to the temperature reached by the heating zone. The function of the cooling zone is to provide sufficient cooling for the dried sheet metal prints. However, if cooling is not possible, the paint film is easily scratched by each other when the sheet metal is stacked, and the fork after stacking is prone to sticking. The baking time is related to the machine speed. If the speed is too fast, the entire monotonic time will be shortened, and the coating ink baking is not sufficient during the peak temperature time, resulting in the ink and coating film being tender due to monotony. Ultimately, it leads to the occurrence of a phenomenon of food or beverage changing taste after contact with it.
If the machine speed is too slow, it can cause excessive baking. In this case, many coatings become brittle and are prone to peeling or exploding during processing. Overbaking together can also cause discoloration of paint and ink. The way to avoid poor baking is to check the curve in the automatic temperature control device of the oven on time to ensure the peak temperature time at standard time.