Papermaking Cellulose Pulps from Cotton Raw Materials, 1998 North America Nonwood Fiber Symposium Proceedings

The principal sources of raw material for papermaking cellulose pulps based on cotton available in dry, sheeted, baled form are first cut and second cut cotton linters and staple fiber from denim rags and cuttings. The staple fiber and linter fiber differ greatly in morphology. Raw material selection, alkaline digesting, bleaching, and both wet and dry mechanical cleaning are aspects of pulping and purification. Data are presented to show effects of alkaline digesting variables on cotton cellulose DP. The principal attributes which determine the papermaking properties of cotton pulps are staple fiber content, viscosity and initial fiber length. All papermaking pulps from cotton cellulose are pre-refined. Staple fiber pulps with high viscosity and high initial fiber length yield exceptional fold and other tensile related properties. First cut cotton linter pulps find a niche as a result of their staple fiber content.

Second cut cotton linter pulps can be tailored in terms of viscosity and initial fiber length to situations and applications to address refining capacity available, formation requirements, and strength requirements. These cellulose materials are also useful in bulky, porous papers. The brightness, cleanliness, purity, diversity and morphology of cotton-based pulps make them suitable for many applications in fine and technical papers.