| Author | Monurizzaman, Md. |
| Call Number | AIT RSPR no.PP-09-03 |
| Subject(s) | Waste paper--Recycling
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| Note | A research submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Pulp and Paper Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The consumption rate of recycled fibers is increasing in the world. Especially, chemical recycled fibers or paper have lower strengths than virgin and mechanically recycled fiber. The main reason is that due to recycle of chemical fiber become stiffer; therefore, it becomes resistant to swelling (horrification). As a result flexibility as well as bonding potential has been lost. But, nowadays, many of the scientists don’t believe that fiber bonding can only be lost due to hornification because fiber to fiber bonding is only responsible for fiber surface. Therefore, they have emphasized on surface modification of recycled fiber to restore the fiber i.e. paper properties. In this modification context, Layer by Layer (LbL) is a new method that has been conducted for soft wood bleached recycled Kraft (SBK) pulp (pine). In this experiment, hand sheet made at first cycle C1 from SBK were recycled in three cycles respectively C1, C2, C3.The mechanical strength and optical properties for each cycle were investigated. All mechanical strengths were low at 3rd cycle; for example tensile index, internal bond, apparent density is low and bending stiffness is high. But optical has been improved at 2nd cycle C2. In order to restore the paper properties, recycled C2 were modified by LbL technique. The C2 were investigated for 2, 4, and 6 bi-layers (bl) and was considered respectively as 2blC3,4blC3,6blC3.In LbL technique 1% Chitosan (CS) and 1% Carboxymethylcellulose (CMC) were used on the basis of oven dry pulp. The optimum results were obtained at 6blC3 and the tensile index at 6blC3 was 50.025 N-m/g where as the tensile index at C2 was 40.21N-m/g. Other mechanical strength like wise tear, internal bond, apparent density, increased at 6blC3; moreover, bending stiffness also becomes decreased at this position. However, the zeta potential for both CS and CMC has been increased in positive and negative zone respectively. Additionally, pH for CS is stating in acidic zone and for CMC it staying in basic zone. Importantly, CS and CMC has great role to modify the stiffer surface and on bonding potential of the fibers. Therefore, surface modification is important in recycled Paper Industry. |
| Year | 2009 |
| Type | Research Study Project Report (RSPR) |
| 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) | Viljakainen, Esa ;Lehtinen, Esa; |
| Scholarship Donor(s) | Finland;Asian Institute of Technology Fellowship; |
| Degree | Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 2009 |