Overview of the Manufacturing Process for Paper and Board
Papermaking today includes, in principle, the same process steps as applied for centuries: preparation of the fiber material, sheet or web forming, pressing, dry¬ing, sizing and smoothing. However, in the last two centuries much of the detail has changed. Each process step has undergone – and still undergoes today – in¬tensive research and development work to meet economic and ecological require¬ments. All links in the chain between fiber and end user contribute to this pro¬gress. The chain does not only include the paper producing industry itself and its suppliers such as the machine and chemical industry, but also the paper industry’s customers and related industries, e. g. printing-houses, printing ink and printing machine suppliers and the manufacturers of corrugated board.
R&D focus has been on economic and environmental aspects such as
. • reduction in consumption of raw material, energy and water as well as noise reduction
. • high machine runnability and long lifetime of machinery and its components
• improvement of paper and board quality with respect to improvement of con¬verting quality
which has led to results of high practical value such as
. • better understanding and consequent control of the whole process in a narrow band
. • reduction in fiber consumption by reducing basis weight at the same quality level and practical value
. • increased ratio of recycled fibers in graphic paper production, with up to 100 % for newsprint and a growing ratio in high grades such as supercalendered (SC) and light weight coated (LWC) papers
. • fillers and coatings replacing part of the expensive fiber material and improving quality
. • new coating and calendering technologies
. • higher safety in Yankee dryer and suction press roll operation
. • new methods of material design for fighting wear of machine components
.• minimum number of personnel involved in the paper and board production process.
.R&D work is supported by modern tools and sciences e. g.
. • process analysis using advanced measuring and analysis techniques
. • process simulation and advanced control techniques
. • morphological characterization of fibers for papermaking
. • chemistry developing functional and process chemicals
. • finite element method (FEM) and computational fluid dynamics (CFD)
. • visualization techniques in the micro- or nano-ranges, video documentation and analysis
.• material sciences including plasma ions implantation into the base material at low temperatures.
.The papermaking process (Fig. 1.2) starts with the delivery of the raw material of the stock components. These are
.• fibers such as
.– virgin pulps (chemical or mechanical) which are usually supplied in bales or, in special cases, as a suspension when both pulp and paper are manufactured at the same location (integrated processing)
.– recovered paper in bales or as loose material
. • fillers and pigments
. • chemical additives
. • coating colors when coated paper is produced.