Profiling the wood and pulping properties of southern pine thinning resources

摘要

This study established the chemical and physical properties of chips and kraft pulps made from southern softwood thinnings and mature wood.Differences in physical pulp properties were established and shown to be due to the effects of the wood furnish.Carbohydrate analysis demonstrated distinct differences in wood carbohydrates,including increased levels of glucose and reduced levels of xylan for mature wood samples.When we used constant kraft pulping conditions,the mature wood samples provided a 1% increase in screened pulp and 12% reduction in pulp kappa number.Mixtures of thinnings and mature wood provided pulps that were a composite average between the two extremes of 100% mature and 100% thinning wood fiber resources.The differences in wood carbohydrates were shown to influence pulp carbohydrate profiles,hexenuronic acids,and fiber charge.Fiber quality analysis indicated that the kraft pulps prepared from wood thinnings were approx30% shorter;this yielded handsheets that were denser and had higher tensile strengths.