Paper surface wetting

The chief source of acidity in paper is the alum used in the papermaking process. Paper (largely cellulose) i6 a very hydrophilic substance, and its surface has a high specific energy. Thus, water readily wets paper surfaces. The very porous structure of paper makes it act like a sponge in the presence of liquids. Hence, various chemicals have been developed to make paper reasonably water... 

Uses Defoamer, processing aid for elimination of entrained air and surface foam for pulp/paper industry, wet-end processes, size press sol ns., calender stack, waste treatment and effluent systems, paints, food-con-tact paper/paperboard Features Water-based high-efficiency Regulatory FDA 21 CFR 176.210... 

ASTMD724-99 Standard Test Method for Surface Wettability of Paper— This method covers the quantitative determination of the resistance of paper surfaces to wetting by measuring the behavior of a drop of liquid applied directly to the paper surface. 

TAPPI T458 Surface Wettability of Paper—In this method, the contact angle between air and liquid on a paper surface is taken as a measure of the resistance of the paper surface to wetting by the liquid. The initial angle of contact or initial wettability is considered to be a measure of the ruling quality of the paper. The rate of change in the wettability is considered to be a measure of the writing quality. 

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