The characterization of hemp (Cannabis sativa L.) chemical pulp and paper.
Published: 2004
Language: eng
Number of pages: 154
Description: Hemp, a non-forest based plant, is an ideal fibrous resource that is suited for use in the Pulp and Paper products sector. It is an annual plant that can be harvested within 90 days of seeding and has both morphological characteristics (long and short cells within its stem) and chemical composition (low lignin, high holocellulose) conducive for high quality papermaking. The focus of this research is to provide an evaluation of hemp fibre as a furnish for pulp and paper applications in the Canadian context.Laboratory scale experiments were carried out to study the degradation of hemicellulose constituents during chemical (Kraft) pulping processes. The neutral sugars of L-rhamnose, L-arabinose, D-galactose, D-glucose, D-xylose, and D-mannose were quantified using high pH anion exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). The primary hemicellulose constituent in hemp raw material was xylose and glucose. The analysis of the pulps indicated an initial dissolution of 25% of the primary hemicellulose constituents of hemp, a significant improvement over traditional pulp wood species of aspen and spruce, which showed an initial hemicellulose dissolution of 41% and 81% respectively. Following initial dissolution, the hemp hemicelluloses were unaffected during the Kraft pulping until the temperature reached 170&deg;C. At this temperature, the measured concentration of the major constituents was significantly higher than at the lower temperatures, suggesting that during the alkali hydrolysis, more hemicellulose fragments were produced.Handsheets produced with aspen/hemp fibre blends displayed different structural characteristics in comparison to pure aspen sheets. The density distribution of the aspen/hemp blended sheets was investigated using an X-Ray method developed in the course of this research project. The blended aspen/hemp paper showed a significantly higher average sheet density, which accounted for the higher strength values observed.Using a pilot-scale digester, hemp pulp was produced and blend with aspen Kraft pulp. The reinforcing potential of the hemp fibre within the pulp blend was studied utilizing measures such as tensile index, tear index, burst index and sheet bulk, which were used to asses the strength changes in the blended paper produced. Of these measured characteristics, tensile strength was the most responsive to successive increases in the hemp content in the sheet.
Notes: Adviser:  D. N. Roy.

Thesis (Ph.D.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Dissertation Abstracts International, Volume: 65-10, Section: B, page: 4916.