1994 Fiscal Year Final Research Report Summary
Research on Deinking of Toner Printed Paper during Recycling
| Project/Area Number |
05806024
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
林産学
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
OKAYAMA Takayuki Tokyo University of Agriculture and Technology, Associate Professor, 農学部, 助教授 (70134799)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Waste Paper / Deinking / Flotation / Brightness / Toner / Oxygen-alkali Treatment |
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| Research Abstract |
(1) On the adhesion of toner to paper surface
A simple joint-strength measurement of paper heat-bonded to polymeric toner was used to evaluate whether the paper-polymer adhesion is sufficient. It was demonstrated that the bonding strength to the paper-polymer interface strongly depends on the sizing treatment. The bonding strength once increased with amount of alkyl ketene dimer sizing agent, followed by a large decrease. The change in bonding strength correlated with change in surface free energy of paper, particularly dispersive force component, as measured by the two liquid contact angle method.
(2) Deinking of toner printed waste paper using oxygen-alkali treatment
The oxygen-alkali treatment was investigated for deinking toner printed waste papers. The oxygen-alkali treatment at 70ﾟC peformed a higher deinkability of toner printed paper compared with the conventional flotation deinking process. The oxygen-alkali treated pulp showed over 82% in brightness and over 96% in ink removal efficiency. Also visible large ink specks over 60 mum was substantially removed by the oxygen-alkali deinking process.
(3) Dry disintegration method of toner printed waste paper
Conventional deinking processes such as washing and flotation are not satisfactory to produce pulp clean enough for reclaiming speck-free pulp. A laboratory pulverizer "Turbo-mill" was employed to fiberize the toner printed waste paper in dry state. As a result, toners in the fiberized pulp were also pulverized into fine particles around 40 mum. However, strength properties such as tensile, tear and folding were considerably lowered by the dry disintegration method.
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