| 摘要 |
A new quality of uncoated paper and board products, such as liquid board or white top liner, of one or more layers with a top layer of bleached chemical pulp is described. The top layer surface has a gloss value of 20-50 %, a coefficient of gloss variation in the wavelength region 3-30 mm of less than 5 %, and a surface roughness (PPS-10) of 2 - 5 mu m. The good printability of the disclosed products makes them useful in the production of packages. The disclosed products are obtainable by a paper making process wherein the calendering of the paper or board is performed with an extended soft nip calender which has a heated, e.g. internally induction heated, roll with a temperature at the surface of 250 to 350 DEG C, and the pressure against the paper board of 5-40 MPa. The calendering operation is optionally preceded by application of steam onto the top of the paper or board web. |
