Mineral fillers are mainly utilized in the production of printing and writing papers (P&W) to improve their optical features and their vulnerability to printing. With the high cost of pulp, the aim of their introduction has been to increase mineral loading in paper and reduce the overall cost of production. For many years the only method of paper formation was acid technology, while the only raw material of choice for filling and coating paper and cardboard was kaolin (in the beginning of the 1970s it was 80% of fillers and 94% of coating grades used in Western Europe, while in the USA – 92% and 96%, respectively). The onset on new methods of acid-free (alkaline) paper forming caused a drastic reduction in the kaolin demand for cost-competitive calcium carbonate: GCC – Ground Calcium Carbonate) and PCC – Precipitated Calcium Carbonate. This also resulted from the progressive self-destruction of machine-made acid papers. In 2013, the share of calcium carbonate in the total production of fillers was 83%, while kaolin accounted for 10%, and talc – 7%. The article presents the parameters of principal mineral fillers for the paper industry and the main reasons why they are suitable for particular kinds of paper. Kaolin, due to the platy nature of its main mineral constituent – kaolinite, is preferred in multiple coating papers. The choice of GCC is beneficial because of its low price and properties (especially whiteness). PCC , due to the possibility of shape and particle size modification serves as filler in uncoated woodfree papers, the key features of which are expected to be lightness and opacity. Size distribution is the main difference between PCC and GCC . The article also presents tendencies observed over the last several years in the paper market in Poland, i.e. in a significant growth in coated paper and board for packaging, as well as the decreasing demand for newspaper, which is a consequence of progressive digitalization.
This study presents a customized root cause analysis approach to investigate the reasons, provide improvements measures for the cost overruns, and schedule slippage in papermachine- building projects. The proposed approach is an analytical-survey approach that uses both actual technical data and experts’ opinions. Various analysis tools are embedded in the approach including: data collection and clustering, interviews with experts, 5-Whys, Pareto charts, cause and effect diagram, and critical ratio control charts. The approach was implemented on seven projects obtained from a leading international paper machine supplier. As a result, it was found that the main causes behind cost and schedule deviations are products’ related; including technical accidents in the Press section, damaged parts, design issues, optimization of the machine and missing parts. Based on the results, prevention measures were perceived.