Analyses on Chemical Composition Fiber Morphology and Pulping Properties of Broussonetia papyrifera Bark Produced in Dry-hot Valley of the Jinshajiang River

The chemical compositions, fiber morphology and physical pulping characteristics of Broussonetia papyrifera bark produced in dry-hot valley of the Jinshajiang River were analyzed. The results are as follows:The lignin content was low and the holocellulose content was high in the bast part of the bark. The fiber of the bark was of great utilization value for its cellulose content reached 43.06%. The fiber length ranged from 3.3mm to 16.94mm with the average length 9.37 mm, and the ratio of fiber length to width was 509, indicating the bark fiber should be an excellent raw material for long-fiber making. According to the laboratory measurements, the pulp yield was 42.47%,the hardness (the Kappa value) was 6.70, the burst resistance index was 2.23 kPa·m/g, the tearing index was 34.53 mN·m/g, the folding endurance value was 192, and the tension resistance value was 27.67 N·m/g. These indexes showed that the bark of Broussonetia papyrifera produced in dry-hot valley of the Jinshajiang River was well suitable for pulp making.