Abstract
The aim of the study was to investigate how base paper characteristics influence coating layer formation and coverage in coating paper with a metered size press. Laboratory woodfree base sheets were produced on a dynamic sheet former. The sheet properties were changed by varying softwood pulp refining and alkyl ketene dimer sizing. The base sheets were taped on a supporting mil paper and coated on a pilot metered size press at 1000 m/min. Coating layer formation was controlled by base paper permeability, which dictated coating colour penetration into the surface voids. The coating coverage was measured with a scanning electron microscope in the backscattering mode. Coating coverage was higher on the denser paper, even though the coat weight was lower. The internal/hydrophobic sizing of the fibres had no effect on the coat weight and coating coverage. The main transport mechanism was pressure-induced penetration of the coating colour into the surface voids.
| Original language | English |
|---|---|
| Pages (from-to) | 159-166 |
| Number of pages | 8 |
| Journal | Journal of Pulp and Paper Science |
| Volume | 29 |
| Issue number | 5 |
| Publication status | Published - 1 May 2003 |
| MoE publication type | Not Eligible |
Keywords
- Coating color
- Covering power
- Density
- Layers
- Metering equipment
- Paper properties
- Paper stock
- Permeability
- Size presses
- Surface sizing