Total addition rates of 3% only guarantee progress in papermaking
Natural chemical additives have played an important role at the raw material preparation stage since the earliest beginnings of handmade papermaking more than two thousand years ago. Up until the end of the eighteenth century, chemical additives from natural resources were used to increase paper strength, to generate better writing and printing characteristics, to enhance its brightness, and to color it. With the invention of the paper machine, chemicals began to contribute to industrial papermaking processes. It was only when newly developed bleaching chemicals came to use that wood pulp as a new source of raw material could be exploited to the full. The chemical additives assisted automation and productivity of the papermaking process well as the enhancement of paper quality and thus contributed to a large degree to the growth of the paper industry in the first half of the twentieth century. The past 50 years have been characterized by the increased use of recovered paper and white natural pigments as fillers and for paper coating as raw materials, by an ongoing improvement of the paper machine productivity, and an emphasis on economics, ecology and quality, all this supported by chemical additives and their creative application.
On a global view paper and board consist today to nearly 99 % of natural materials: Fibers from chemical and mechanical pulps add up to 48 % of the total raw material consumption. Recovered paper makes up to 40 %. Non-fiber material as fillers and coating pigments are 10 %. The remaining 3 % are ”Chemical Additives” (solid materials), hereof 1,6% are starch based products. In addition to that further 1 % of so called Basic and Bleaching Chemicals. These chemicals as such do not remain in the paper (they get decomposed and lead to the untreated waste water). Traditional papermaking chemicals such as aluminium sulphate (so called alum) and nowadays other aluminium compounds are still used at a rate of 0,3 % on paper respectively 10 % portion of the total dry based volume of chemical additives. Pure synthetic chemicals – mentioned as ”Specialty Chemicals” account for only 1,1 % of the raw materials that are used at the paper and board making process.
21 billion €-a significant production cost factor
The market for all chemicals which are worldwide used for the production of Pulp and Paper is currently estimated at 21 billion €. Nearly 40% of this are Basic and Bleaching Chemicals, mainly used in the production of pulp and the other approx. 60% are chemical additives used in the production of paper and board.
About half of these 3% Chemical Additives is starch, which is also derived from renewable raw materials and one sixth is the traditional chemical papermakers' alum, i.e. aluminium sulphate. Only 1.1 per cent of the raw materials used for paper production are synthetic chemical additives. In addition it is necessary to use about 1% of basic chemicals and bleaching chemicals e.g. sodium hydroxide or sulfuric acid for pH regulation. How-ever, these chemicals do not end up in the final paper. product.