TAPPI UM 579

Abstract

This method describes a procedure for measuring water repellence of paper, paperboard, or combined board which has been treated to produce water repellency. The method can be used for a wide range of products, from sheets having only slight water repellency to sheets with wax sizings or coatings that have a high degree of water repellency. This method is useful for sheets treated with such materials as a stearic chrome complex, polyvinylidine chloride, polyvinyl compounds, commercial varnishes, paraffin wax impregnations, and paraffin wax coatings. The sheets may be produced directly on the paper machine or subsequently coated. The method is not practical for plastic extrusion coatings, heavily wax-coated, nor certain curtain-coated grades which have a hard wax/resin type of coating, for which the test period becomes prohibitively lengthy.