Hüseyin Kirci

Suitability of kiwi (Actinidia sinensis Planch.) prunings for particleboard manufacturing

Abstract The aim of this study was to investigate the suitability of kiwi prunings as a raw material for particleboard manufacturing. The kiwi is a new cultivation in the East Black Sea Region of Turkey. Kiwi pruning particles and industrial wood particles in various proportions were used as the raw material for the core and surface layers of the three-layer particleboard. Commercial urea formaldehyde (UF) adhesive was used as a binder. Anatomical descriptions, chemical properties (holocellulose, cellulose, lignin and ash contents, alcohol–benzene, hot and cold water solubility, solubility in dilute alkali (1% NaOH)) and basic characteristics of the kiwi stalks (density, weight proportion of bark, core and pith), physical (thickness swelling (TS), water absorption (WA)), and mechanical (modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB)) properties of particleboards were determined. The results showed that kiwi stalks had higher fiber length, width and wall thickness values than the wood of common forest species. They had higher solubility values, lignin and ash contents than those of the other plants. Increasing of kiwi pruning particles usage in the core negatively affects the board properties. Containing up to 50% kiwi pruning particles in the core, the MOR exceed the minimum requirements of the European standards, for general purpose. All of the particleboards produced from kiwi prunings had IB higher than the requirement. The WA and TS values were very high (poor).

A new modified pulping process alternative to sulphate method “Alkali-Sulfite-Antraquinone-Ethanol (ASAE)”

SummaryIn this study, ASAM method was modified by the use of ethanol instead of methanol. This new organosolv pulping method is referred to as ASAE. Brutia pine (Pinus brutia Ten.) was chosen as raw material in cooking because of its wide-spread usage in Turkish sulphate mills. 28 cooks were made by changing the cooking conditions systematically to achieve the most effective cooking parameters for yield and physical properties of ASAE pulps. Also, a control sulphate cook was made. After statistical evaluations of the data optimum pulping conditions were determined to be 20% Na2SO3 with 50% ethanol ratios and 150 min cooking time at maximal temperature. It was found that ASAE pulps had higher yield, viscosity, brigthness and strength properties than sulphate control pulps with the exception of breaking length. Furthermore bad-odour problems were absent during the blowing and washing process in the laboratory trials.

Effect of anthraquinone on brightness value and crystalline structure of pulp during soda processes

The dependence of crystalline structure and optical properties of pulp on anthraquinone (AQ) added to the soda process at different cooking times was determined in this study. Wheat (Triticum aestevum L.) straw was used as the raw material for pulp. Soda and soda-AQ processes were selected for pulping at 80 min and 120 min. The soda-AQ process improved the yield and viscosity of pulp delignification ratio for pulping in comparison with the soda process. Crystallinity of pulp samples decreased by adding anthraquinone to the soda process because of stabilized less ordered cellulose and amorphous hemicelluloses in pulp. It was determined that crystallinity of pulp samples decreased with longer cooking time, from 80 min to 120 min, in both soda and soda-AQ processes. Monoclinic structure was dominant in pulp samples; however, the triclinic structure ratio increased in both soda and soda-AQ processes compared to raw material. It was found that brightness and lightness values in pulp samples decreased when using anthraquinone depending on the changes of the crystalline structure.

Influence of plum gum and sodium perborate addition on spruce kraft pulp properties during oxygen delignification

The aim of this study was to investigate the effects of plum gum liquor and sodium perborate addition to oxygen delignification process on spruce kraft pulp properties. Yields and viscosity of pulp were protected against oxidative attack, when kappa number of pulp was not changed by adding plum gum to oxygen delignification process. Delignification ratio improved by 7.4% without any viscosity loss by adding only 0.25% sodium perborate as active oxygen with plum gum liquor to the oxygen delignification process. It was found that crystallinity of pulp was improved by adding plum gum and sodium perborate to oxygen delignification. It was also determined that sodium perborate had an affirmative effect on delignification ratio, when plum gum affected pulp viscosity positively.