The dryer is a common part of the paper machine, and its surface condition directly affects the quality of the paper. The main reason for the deterioration of the surface condition of the dryer is corrosion and abrasion, the wear of the pulp and its impurities, and the uneven scratching of the scraper all cause scratches on the surface of the dryer. The survey shows that most of the dryers need to be ground after one year of use, and the dryers with serious corrosion and wear need to be ground for half a year. The application of thermal spraying technology in the paper industry is very mature, mainly used in the surface treatment of paper machine dryers, increasing the finish and hardness of the dryer surface, reducing production costs, and improving paper quality. When thermal spraying dryers, always pay attention to the following:
1. Surface leveling: For long-term use of the dryer, due to local wear or corrosion, it is easy to appear pits and scars, which need to be smoothed or leveled in advance.
2. Degreasing and grease removal: In the process of processing and transportation, grease will occasionally stick, and the next link will be carried out after degreasing.
3. Sandblasting and rust removal: Before spraying, the surface needs to be sandblasted out to play the role of rust removal and cleaning.
4. Spraying: Spraying is the main process link, which needs to follow the principle of "spraying up and down and moving the left side, and completing the slices" to avoid uneven spraying or overheating of the surface.
5. Pre-acceptance: mainly check the thickness of the coating, whether the spraying is uniform, whether there is any leakage, whether there are cracks and falling off on the surface.
6. Hole sealing: For anti-corrosion coatings, it is necessary to seal holes, and pay attention to the selection of hole sealers with good permeability, high temperature resistance and corrosion resistance when sealing holes.