Condebelt press drying and sustainable paper cycle

摘要

The Condebelt process is based on the condensing belt principle and it is a very promising method, offering several advantages over conventional cylinder drying. At the moment, it is best suited to board grades, but it has also a considerable potential with paper grades. In this process drying shrinkage of the web is eliminated, and even stiff fibers can effectively be plasticized and bonded to each other. Compared to cylinder drying, this results in improved strength properties, especially in the cross-machine direction. This drying process offers opportunities for lowering the grammage of board, reducing the weight of corrugated boxes, increasing the use of recycled furnishes and high-yield pulps. The disintegration of condensing belt dried board needs slightly more energy than cylinder-dried board. However, the recy-clability of the board is good, especially when the re-made web is dried using the condensing belt process. The deterioration of board properties after multiple recycling and condensing belt drying is quite moderate. This shows that condensing belt drying can form part of a ecologically sustainable paper cycle.