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The purpose of this study was to evaluate the feasibility of using highly filled powders as electrostatically applied paper coatings. Powders prepared by two different methods were suitable for electrostatic deposition and they attached to the paper surface with a grounded backing. Pressing at elevated temperatures turned out to be a crucial process step for improving the adhesive and cohesive strengths of the powder coating layer on paper. Limited mechanical interlocking with the base paper and an uneven pressure profile were factors impairing the surface strength of the coated paper. On the other hand, factors such as higher polymer content, higher pressing temperature, pre-heating the paper prior to coating, and increasing the number of hot roll nips increased adhesion between the coating and the base paper. Powder coatings as such had uneven thickness, and they displayed a relatively broad pore size distribution. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the feasibility of using highly filled powders with 100 parts per weight of calcium carbonate and 10 parts per weight of polymer, acting as binder, as electrostatically applied paper coatings. Such powders prepared by different methods were evaluated as being suitable for electrostatic coating. Powders compacted at elevated temperatures demonstrated cohesion superior to that of calcium carbonate, and at best similar to that of aqueous coatings. Cohesion, porosity and thus absorption properties of compacted powders were affected by the powder preparation method, compaction process, and powder composition. Powders containing semicrystalline polymer turned out to be the most interesting for further testing. [ABSTRACT FROM AUTHOR]

Abstract: Mercury intrusion is frequently used for the characterization of porous materials, giving access to parameters such as porosity and pore size distribution as well as density (skeletal and bulk).The present work aims at studying the suitability of the mercury intrusion technique to evaluate the pore structure and related information of different kinds of woods used for pulp production, pulp handsheets and commercial paper sheets. Differences in wood structure, pulp composition and paper composition and structure could be easily detected by changes in the measured parameters, thus enabling a better understanding and/or prediction of the behaviour of these materials. [Copyright &y& Elsevier]

Many industrial units apply wanted or unwanted impact loads to particles. Such units include comminution units as ball-mill, pin-mill or jet-mill, as well as conveying systems such as pneumatic conveying pipelines and chutes. Regardless of whether the impact load is wanted or unwanted, it causes damage to the particles. The number of collisions also has a major effect on the damage caused to the particles. Since systems commonly used in industry are similar in many ways (differing only by the range of impact velocities and number of impacts) their effect on the damage caused to the particles could be commonly evaluated based on the impact velocity and the number of collisions.In this paper, the fatigue behavior of the same material tested in four impact comminution and attrition units is compared for the first time. Fatigue curves common to the four impact units are presented. The ability to plot a single fatigue curve for various impact systems enables to predict the expected size reduction in any new impact system based on past experience with other impact systems, as will be demonstrated in the paper. [Copyright &y& Elsevier]