The use of chitosan in the production of high quality printing paper | |
| Author | Pranee Lertsutthiwong |
| Call Number | AIT Diss. no.BP-02-01 |
| Subject(s) | Chitosan Paper--Printing properties Paper--Quality |
| Note | A dissertation submitted in partial fulfillment of the requirement for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. BP-02-01 |
| Abstract | ln this study, the production of high quality printing paper has been investigated by application of the cationic biopolymer chitosan as a dry strength and surface sizing agent. The effect of the chitosan on paper quality is influenced by its physico-chemical properties. These properties are in tum influenced by the specific process conditions during the extraction of chitin from its natural source, shellfish biowaste and during the conversion of chitin into chitosan. This study is separated into 3 parts: the first part is to investigate the effect of different extraction conditions on the properties of chitosan; the second is to evaluate the use of chitosan as a dry strength agent; the last is to determine the effect of chitosan on the surface properties of paper, on the quality of offset printing using a proof offset machine and on the properties of chitosan paper during aging. High molecular weight chitosan added at the wet-end was used for the determination of the effect of chitosan on the properties of handsheets made from bleached eucalyptus pulp. The dosage of chitosan and the pH conditions affect the properties of the handsheets. The results demonstrate that addition of chitosan up to 1% improves the mechanical properties of the paper. The improvement of the strength properties is higher in chitosan concentration from O to 0.5% compared to 0.5 to 1%. Chitosan is an effective dry strength additive either in acidic or neutral condition, but is less effective at alkaline condition. The utilization of chitosan in sizing to improve surface properties of paper for offset printing depends on the concentration and the molecular weight of the chitosan. The results show that chitosan in a concentration of 2% and a molecular weight of one million dalton gave the highest improvement of air resistance, surface strength and printability. The effect of chitosan has been compared with oxidized starch and polyvinyl alcohol. The result shows that chitosan, oxidized starch and polyvinyl alcohol separately or in combination can improve printability to various extend. Small amounts of chitosan have a relatively large effect. It is recommended to use chitosan as an additive to oxidized starch in large scale surface sizing of printing paper. The effect of chitosan on offset printing quality in terms of dot gain has been investigated using a proof offset machine. Papers sized with oxidized starch containing 0.4% chitosan show better printing quality than those sized with 10% oxidized starch or 10% polyvinyl alcohol. The properties of printing paper change during aging. In the conventional alkali process, oxidized starch is used for surface sizing application. From the results of this experiment, the use of chitosan in optimum dosage in oxidized starch formulation did not show significant difference in brightness, yellowness and pH compared with the use of oxidized starch afier aging. Therefore, chitosan can be used in surface sizing formulation for permanent paper. The overall conclusion is that chitosan is an attractive biodegradable agent to be used in the wet-end production and in the surface sizing of high quality printing paper. Chitosan is especially recommended to be used as an additive in conventional surface sizing formulation. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. BP-02-01 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bioprocess Technology (BP) |
| Chairperson(s) | Stevens, Willem F.; |
| Examination Committee(s) | Suwalee Chandrkrachang;Nazhad, Mousa M.;Ruhanen, Mauno;Kolehmainen, Heikki;Udomchai Chinadit;Kobayashi, Yoshinari; |
| Scholarship Donor(s) | Asian Institute of Technology; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2002 |