The prepared coating was coated on base paper in a laboratory Bar Coater. The coating method is bar-type single-layer coating. The selected coating bar is a red coating bar. The coated paper sample is dried in a hot air dryer. The specific coating conditions are as follows:
Coating speed: 4m/min
Drying temperature: 120℃
Drying time: 1min
Coating thickness: 12μm
Coating amount: 18.8-21.6g/m2
Laboratory temperature: 23.8℃
Laboratory humidity: 64.5RH
The figure below is a schematic diagram of the coating process on the laboratory coater. During the coating process, the coating head and the paper web move relative to each other. The external force on the coating in this process mainly comes from the shear force and pressure formed between the coating rod and the base paper when it moves.
The laboratory type coater used in this study belongs to the Bar Coater. The coater bar is a round bar with a metal wire wound on its surface. The size of the gap left between the coating rods, that is, the thickness of the wet coating left on the surface of the base paper, the thicker the wire, the thicker the wet coating left.
Coating base paper is cut according to the width of the coater, and the coating amount can be adjusted by three factors: the selection of the coating rod, the coating speed of the coating rod, and the gap between the coating rod and the coating platform surface. Change, so as to ensure the same amount of coating each time. After the paper web is coated, it is dried in a hot Air Oven, and the drying temperature is ℃ for each time, and the time is. After the paper sample is coated, mark it and place it in a constant temperature and humidity room for an hour before measuring its surface performance index. All samples were not calendered after coating.
