Specific Base Paper Properties Affecting Coating

Specific Base Paper Properties Affecting Coating 

Base paper characteristics have a strong effect on the quality of coated paper and board and process economy. The main properties are as follows  

Porosity If porosity is very high, absorption of coating is also high and coating weight can increase dramatically and drying problems may also occur. 

Formation This property refers to small-scale basis weight variations in paper. There are areas that are denser and less absorbent to the coating than other areas. To reach uniform coating penetration, base paper requires even formation, otherwise mottling may occur in printing. 

Smoothness Smooth base paper gives a uniform and closed coated surface. The various coating processes have slightly different smoothness requirements. Air knife coaters require a relatively smooth surface because, in that method, coating 

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Specific Base Paper Properties Affecting Coating... 

In this paper, we present a study in which combustion catalysts based on silica-coated metal monoliths were prepared. The aim of this study was to prepare washcoated metal monoliths with controlled properties. The properties varied are specific surface area of the washcoat and washcoat thickness or washcoat loading. Furthermore, we discuss how the preparation procedure affects the resulting catalyst properties and related performance. We deposited washcoats based on colloidal silica sols. Colloidal silica sols give porous materials with rather narrow pore size distributions when dried and calcined. This gives us excellent control over the pore size distribution of the washcoat, as will be discussed. The technique presented here, allows deposition of washcoats with controllable thickness in one step, unlike techniques based on pure silica sols, reported elsewhere [7,8]. Washcoats were impregnated with paUadium salts to make active catalysts that were tested in methane combustion. The effects of the preparation procedure of the silica and of the impregnation procedure were studied using particulate catalysts. 

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