Characterization of filled powders for powder coating of paper

• Powders with 100 parts (per weight) of CaCO3 and 10 parts of polymer were studied.
• Electrical properties evaluated suitable for charging, transfer and attachment
• Cohesive strength and porosity similar to paper coatings can be achieved.
• Compaction of powders affected both by powder properties and compaction process
• Semicrystalline polymer as binder proved to show the most potential.

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.

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