| Author | Sutjipto, Erik Rusdi |
| Call Number | AIT Thesis no.PP-06-11 |
| Subject(s) | Kraft paper--Recycling
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| Note | A thesis submitted in pmtial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | In this thesis, 3 types of pulp were used as material, commercial softwood and hardwood kraft pulp, laboratory softwood and hardwood kraft pulp and chemithermomechanical pulp (CTMP). White water circulation system was used during the sheet making to avoid the loss of fines during the process. Each of the pulp was recycled three times and during each cycle strength and optical properties were observed. Refining was done for commercial and laboratory kraft pulp'at the virgin state. PFI mill was used for refining up to 25 SR. It was found that different pulp types showed different recycling effects. CTMP fibres became flatter and more flexible giving a denser stronger sheet. This could be caused by washed away of extractives from the fiber surface, the relative bonded area increased. Tensile, TEA and tear were observed on commercial and laboratory kraft pulp both softwood and hardwood. Reduce in tear index happen only on commercial hardwood. Increased in bending and density was also observed. The change in the hemicellulose content especially arabinose could be the cause of this behavior. The principal effect of recycling on chemical pulp is a loss of fibre bonding ability. This is most noticeable in the first cycle. It may be due to the changes in the fibre surface propeliies. Further research in the swelling ability of recycled fiber is needed. Small change in extractives content of commercial softwood kraft pulp was observed during recycling. Initial value of 0.068% during the virgin state and 0.047% after the third cycle. Fully bleached commercial kraft pulp extractive content was removed mostly during the cooking and bleaching, recycling won't reduce the extractives content for bleached kraft pulp. On the other hand, major decreased in extractives content was observed for CTMP. Initial value of 0.13% extractives contents during the virgin state and 0.016% after the third cycle. The xylose and pentosan content for commercial softwood kraft pulp is relatively unchanged, on the other hand, the xylose and pentosan content for mechanical pulp show a decrease trend each time we recycled the pulp |
| 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) | Lehtinen, Esa;Vilpponen, Aki |
| Scholarship Donor(s) | Government of Finland - AIT Fellowship |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2006 |