STUDIES ON THE WET STRENGTH PAPER

I. WET STRENGTH PAPER PRODUCTION BY MELAMINE FORMALDEHYDE RESIN

Abstract

These papers are devoted to the progress and problems involved in the use of melamine and urea resins for the practical production of wet strength paper. The preparations and properties of melamine formaldehyde, urea melamine formaldehyde copolycondensate, and sulphomethylated urea formaldehyde resin colloidal solutions for the production of wet strength paper, and then the effect of these resin colloidal solutions on the strength of the sheet, and their uses in paper-mill conditions are discussed. The comprehensive investigations reported to date and the fundamental information are available, but unfortunately, very little of the details of both resin preparation and paper production by these various resins are available to date especially in practical mill application. Therefore, the preparation of melamine resin acid colloid solution and the production of wet strength paper by it were tried at first in mill scales.
Examined points are as follows :
1. The effect of the use of rosin size on the strength of the resin treated paper.
2. The effect of HCl or Al₂ (SO₄) ₃ added to paper stock by way of pH control.
3. The effect of the kinds of pulp (K.P or S.P) on the strength.<BE>This paper tells the results of these examinations.