| Abstract: | CONCLUSION. Topic of this diploma thesis is to follow effect of zirconium compounds on permanance and durability of paper as well as to observe of using of zirconium compounds for deacidification and thus to increase permanence and durability of acid papers. In relation to permanence and durability of paper, the accelerated ageing proceeding at 105 °C in neutral sheets and in those impregnated with aluminium sulphate, acid sheets treated with zirconium compound and neutral sheets treated with zirconium compound, all produced from bleached soft hardwood pulp, has been studied. From zirconium compounds used at present time, solution of potassium zirconium carbonate was choose for our experiment. Samples were aged 0, 1, 4, 8 and 12 days because the dependance of observed changes during the ageing was required. From the results of experiments is obviouse acid degradation of paper. This argument is supported by the fact, that paper strength decreases down to the level of paper strength. Either the optical properties of acid sheets are influenced by ageing process what can be further shown in decrease of whiteness and in increase of opacity. It is possible to we can state that potassium zirconium carbonate doesn´t accelerated ageing of sheets and that optical properties are been stabilized by addition of zirconium salts. Addition of potassium zirconium carbonate eliminates degradation effect on acid paper and thus papers stays permanent and they keep their strength even after 12 days of ageing. At present time, papers are still in ageing chamber, where they have been left for the purpose of following long term protection of permanence and durability. |
|---|
