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Combined effects of copper and oil treatment on the properties of Scots pine wood

Can A., Sivrikaya H.

Drewno : prace naukowe, doniesienia, komunikaty

2017

vol. 60, nr 199

89--103

Due to its toxic effect on fungi, for the last 50 years copper has been one of the most widely used materials in the impregnation industry. The ban on CCA (copper-chrome-arsenic), known as an effective deterrent against fungi and insects, has led to the development of new and environmentally-friendly alternatives. Copper-azole (CuA), which is one of the most widely used of the newly-developed materials, is very effective against fungi and insects. However, one of its most serious problems is the fact that copper is leached from the wood. Various factors affect the leaching of copper from wood. One of the most important effects is the duration of fixation. In this study, samples impregnated with copper azole were exposed to a secondary impregnation process using tall oil and linseed oil 24 hours and 5 days, respectively, after the first impregnation. The effects of different fixation durations and oiled impregnation procedures on Scotch pine were investigated. For this purpose, biological, physical and chemical analyses of the wood were performed. Moreover, the amount of copper residual after leaching was also examined. According to the results obtained, it was observed that the duration of fixation had no significant effect on the physical properties, and that the linseed oil improved the physical properties of the wood. Through the copper and oil combination, an improvement in the physical and biological properties of the wood was observed, as well as a decrease in the amount of copper leached out.

Effect of sodium ascorbate on weathering performance of NaOH pulping and paper

Gencer A., Onat S. M., Can A., Ozgul U., Sivrikaya H., Yurdakurban F.

Drewno : prace naukowe, doniesienia, komunikaty

2016

vol. 59, nr 198

49--60

This study aimed to decelerate the weathering of paper from light by utilizing the antioxidant property of sodium ascorbate (SA), which is an ascorbic acid salt. Three different sessions of cooking were carried out by adding 2.5%, 5.0% and 7.5% of SA in proportion to the weight of a completely dried chip in addition to 24% NaOH in order to identify the influence of SA on cooking. It was observed that the pulp yield decreased when SA was added to the cooking. For that reason, it was decided to add SA into the control pulps instead of adding the digester. The same amount of SA was added to the control. The SA-added pulps were held in the agitator initially first for 2 hours and then 12 hours before making paper. So as to determine the influence of the treatment on the process. The paper was treated for 72, 144 and 256 hours and values of ΔL, Δa, Δb and ΔE were identified in order to determine the period of the SA’s efficacy against weathering. The total discoloration in all the samples of paper, displayed an increase with an extension of the time period. The lowest discoloration after a 256-hour time period was seen in the sample group where 7.5% of SA was added and soaked in the water. The final results indicated that the most appropriate concentration was 5% and that pulp suspension must be retained for 12 hours to improve mechanical properties.