Brush Coater is the oldest coating equipment, originally used in the 1850s to use clay coating production wall wallpaper. Brush-type coated head has 3 different types: Round brush coated head, blanket roll coated head and blanket cover coated head. Fig. 1 is an early-used brush coating head.
The advent of the the 1930s air knife coater marks the birth of modern paper coating industry. The gas-knife coater is to overcome the above-mentioned shortcomings of brush coater, which is rapidly promoted, resulting in a sharp increase in the output of coated paper.
The 1950s appeared the first scraper-type coater patent. Since then, the scraper coating machine technology has been rapid development. According to the material equipment, scraper type and the location of the blade installation of different, scraper coating head is also divided into many kinds, such as hard blade coating machine, drag-and-drop scraper coater, soft blade coating machine, fountain-type scraper coater, short resident scraper coater, Bill scraper coater, scraping roller-type coating machine.