CMP pulps of willows for newsprint part 1: Pulps evaluation

MONTEOLIVA S.; AREA, M.C.; FELISSIA, F.E.

CELLULOSE CHEMISTRY AND TECHNOLOGY

Romanian Academy, Publishing House of the Romanian Academy

Año: 2007 vol. 41 p. 263 - 272

0576-9787

Pulping characteristics of six Salix clones were investigated using alkaline sulfite chemimechanical pulping (CMP). The clones studied were S. babylonica var sacramenta named "American willow", and five hybrids, S. babylonica x S. alba `A 250-33´, `A 131-25´, `A 131-27´ and S. matsudana x S. alba `A 13-44´, `NZ 26992´, implanted in 2 sites of culture in Argentina. The sampling sites included a floodable place in the Paranaense Delta, Entre Ríos province, and one continental site in Buenos Aires province. Following wood characterization, 12 alkaline sulfite pulps were prepared using these conditions: pre-vaporization; impregnation with 2.6% o.d. NaOH and 2.6% o.d. Na2SO3; liquor/wood ratio of 5.5/1; 80°C; 40 minutes; and refining. Pulps were refined with a target value of 50-55 ºSR (post-screening). Pulp properties were compared for their use in newsprint. Pulp properties varied significantly, in general, between clones and sites. American willow (tear strength of 3.20 mNm2/g, tensile of 28.2 Nm/g and opacity of 98.6%), 250-33 (tear strength: 4.03 mNm2/g; tensile of 26.8 Nm/g; opacity: 98.6%) and 26992 (torn: 3.51 mNm2/g; traction; 27.6 Nm/g; and opacity of 98.5%), all from Delta site were the predominant ones. Whereas pulp whiteness was generally higher in the Continental site, (reaching 50 %ISO), Delta site was better in mechanical strengths.