| 摘要 |
PCT No. PCT/DE89/00701 Sec. 371 Date Jun. 20, 1991 Sec. 102(e) Date Jun. 20, 1991 PCT Filed Nov. 7, 1989.The calendering occurs in a press nip of a calender with application of pressure, moisture and heat. To achieve a desired surface quality, the surface of the paper or cardboard web which is to be calendered is brought in the press nip to a condition above the glass transition curve of the materials. Prior to expiration of 20 to 60 milliseconds, the surface of the paper web departing from the press nip is subjected to a transition step by virtue of a cooling device first in combination with a change in moisture content to a condition beneath the glass transition point of the material. The cooling can occur during contact of the surface to be cooled with a cooled surface or by direct contact with a cooling, preferably inert gas. After calendering there thus arises a diminished increase in the roughness of the paper web, so that the surface quality obtained in the press nip is predominantly retained. There have been illustrated suitable apparatuses for carrying out the method.
|
