| Author | Le Tien Dung |
| Call Number | AIT Thesis no.PP-06-16 |
| Subject(s) | Ink-jet printing
|
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The scaling is one serious problem in paper machine that used deinked pulp. The major source was claimed to be sticky and carryover chemical from DIP plan. These factors depend strongly on the performance of deinking process. This study was carried out to investigate the influence of water hardness and sodium silicate on the performance of flotation as well as their scaling potential. In these studies, water hardness and sodium silicate dosage were varied. The properties of pulp after repulping and flotation were measured (brightness, ERIC, Extractive content). The scaling potential of sodium silicate and water hardness was assessed by Result from experiment shows that, in the system that uses soap, water hardness have negative effect on the ink detaclm1ent from fiber in the re-pulping stage. It reacts and reduces the performance of soap and increases ink re-deposition. However it improves the ink-removal performance of flotation cell. In practice, when the water hardness is low, some DIP plan adds CaCl2 before flotation stage to achieve high ink removal. Sodium silicate has good effect on ink detachment on re-pulping stage as well as ink removal in flotation stage. It reduces the extractive content of the pulp. Regarding to the scaling problem, Experiment data indicates high water hardness has high potential to fonTI scaling with sodium silicate residual. Too high sodium silicate dosage will lead to deposition on the equipment due to the reaction of sodium silicate with organic compound or with metal earth or with the sock of pH. This reaction produces the gel-like. This gel-like deposit has good affinity with metal surface. Increase the carryover chemical from DIP plan to paper machine will surely increase the scaling potential, especially when system has high silicate residual at the neutralizing point, or system have close white water loop that lead to increase the sodium silicate and other chemical concentration (e.g. metal ion, dissolved organic compound ..) |
| Year | 2006 |
| Type | Thesis |
| 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 | Pulp and Paper Technology (PP) |
| Chairperson(s) | Nazhad, Mousa M. |
| Examination Committee(s) | Malinen, Raimo O.;Lehtinen, Esa |
| Scholarship Donor(s) | Government ofFinland-AIT Fellowship |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2006 |