Abstract: Cellulose dissolved in a suitable solvent and added to an aqueous suspension of paper-making cellulose fibers provides paper of improved dry strength.

Abstract: Chitosan is used to improve the flat crush resistance of corrugating medium. A solution of chitosan in dilute acid is added to corrugating medium pulp containing at least about 0.05%, based on the dry fiber weight, of spent semichemical pulping liquor. The corrugating medium pulp is then formed into corrugating medium sheets, dried and manufactured into corrugating medium.

Abstract: Hardboard is produced by a process wherein wood solubles or sugars released principally during the pulp preparation stage are retained in a closed water system by collecting the process waters released during mechanical dewatering of the pulp to form a mat and returning such water to the system. The mat is dried by thermal evaporation with substantial quantities of sugars being deposited on the mat surfaces as a result. The mat is then pressed under conditions such as to cause flowing and caramelization of the surface sugars thus forming a crust or skin of the sugars on the mat surfaces, which sugars improve the board surface characteristics. A paper overlay may be applied to the mat prior to pressing and bonded thereto by the sugars to provide a paper overlaid hardboard.