Coated Papers
Lightweight Coated or Mediumweight Coated
Coated papers are high-quality magazine papers. They are produced with on-line and off-line coaters for the use in the printing press. The primary end uses are applications where the best quality of printing is required. Examples are fashion magazines, life style magazines, recreation and other sports publications. Their quality is above the uncoated SC grades and below the tandem and enamel coated grades. They are calendered with on-line multinip calenders or off-line with super or multinip calenders. The calendering process is used to achieve the higher gloss levels required of these grades. One of the most demanding processes today is on-line LWC (lightweight coated). The requirements are extremely high on achieving process uniformity for basis weight and moisture in both the MD and CD directions. To create a consistent moisture level upstream of the coater for even coating application, there is a need for one or two SteamTech steamshowers in the press section. Uneven pick-up will cause severe runability problems in the supercalenders and reel building. |
The steamshowers are engineered with the smallest zones in the industry, 50mm profiles zones, this provides high-definition profile control with maximum energy transfer. These steamshowers can typically increase the sheet dryness 3%, and normally have a profile capability of up to 2.5% moisture. The resulting 2-sigma values are 0.2% and lower. Due to the large throughput and the high speed of the on-line process, the steamshowers are really high technology tools with steam amounts of up to 10,000 kg/h with high-velocity steam. They have separate zones for heating the web, felt heating, profiling and sealing zones. This applications-matched configuration is especially critical in on-line LWC, where speeds over 100 km/h are already being achieved. Page 1 of 3 |
